Séisme en Haïti - 12 janvier 2010
Dossier réalisé par Marie-José Broussaud et Caroline Prevot
pour Eduterre-usage- INRP.
Cette création est mise à disposition sous un contrat Creative Commons.

Aide à la navigation
Informations techniques à respecter :
1) Dans "Infos pratiques" ou "Données géographiques" : tout décocher
2) Dans l'onglet "Outils..."/Option/Vue 3D cocher" Afficher le Relief" et modifier le facteur d'élévation entre 0.5 et 3
3) Dans l'Onglet"Outils..."/Options/Général cocher "Afficher les résultats web dans un navigateur externe
4) Pour ouvrir un dossier cliquer sur +, un - apparait alors.
5)- Un clic sur le nom du dossier permet d'afficher un texte
- Deux clics permettent de se rendre au lieu désiré
6) Les couches de données se superposent à l'écran selon l'ordre dans lequels vous les affichez. Par exemple si vous voulez superposer les structures à une carte, il faut les afficher en dernier.
7) Au fur et à mesure, décocher les données non utilisées et les cartes qui ne sont pas à la bonne échelle
8) Après chaque vision 3D se remettre à plat en utilisant le contrôle de navigation.
Attention!
- ne jamais perdre le Nord
- pour voir le relief, 2 possibilités :
a) Enfoncer la touche "shift" et avec la molette de la souris changer l'angle de vision
b) Utiliser les contrôles de navigation.
- En bas de certaines pages, ne pas tenir compte de :
Itinéraire : Vers ce lieu - À partir de ce lieu
Prise en main :

Cartes topographique et bathymétrique

ETOPO1 Ice Surface
NOAA > NESDIS > NGDC > MGGD > Global Relief
ETOPO1 Global Relief Model
Preliminary Release - in Review (Minor Revision August 29, 2008)
ETOPO1 is a 1 arc-minute global relief model of Earth's surface that integrates land topography and ocean bathymetry. It was built from numerous global and regional data sets.
Available Versions:
ETOPO1 Ice Surface: Grid of Earth's surface that depicts the top of the Antarctic and Greenland ice sheets.
ETOPO1 Bedrock: Grid of Earth's surface that depics the bedrock underneath the ice sheets.
Relief for the rest of the world is the same in both versions.
Custom Grids: Custom regional grids can be created online from ETOPO1 using NGDC's 'Create Custom Grids' tool.
How to cite ETOPO1:
Amante, C. and B. W. Eakins, ETOPO1 1 Arc-Minute Global Relief Model: Procedures, Data Sources and Analysis, National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce, Boulder, CO, August 2008.
Imagery of ETOPO1 Ice Surface by J. Varner and E. Lim, Cooperative Institute for Research in Environmental Sciences, at University of Colorado at Boulder and NOAA National Geophysical Data Center.

NOAA NGDC logo

Scale

Haiti (Epicentre du séisme-12/01/2010)
M 7.0, Haiti region

Séismes en temps réel - USGS
Séismes récents ( latitude, longitude, magnitude, profondeur) ,
de moins de 7 jours. mis à jour toutes les 5 minutes.
Site : USGS Real-time Earthquakes

Légende
Profondeur des séismes

USGS Logo

Séismes epicentres

Séismes (historiques)

FID = 1859
LATITUDE = 37,272
LONGITUDE = -116,36
PROFONDEUR = 0
MAGNITUDE = 5,5

FID = 2258
LATITUDE = 34,131
LONGITUDE = -116,408
PROFONDEUR = 0
MAGNITUDE = 5,6

FID = 1902
LATITUDE = 51,637
LONGITUDE = -130,978
PROFONDEUR = 0,2
MAGNITUDE = 6,5

PROFONDEUR = 1

PROFONDEUR = 1,1
MAGNITUDE = 5

PROFONDEUR = 1,2

MAGNITUDE = 5

LATITUDE = -20,082
LONGITUDE = 134,025

LATITUDE = -20,225
LONGITUDE = 133,825

LATITUDE = -15,679

LONGITUDE = 26,7

LATITUDE = -19

LONGITUDE = -104

LATITUDE = 53

LONGITUDE = -177

LATITUDE = 42

LONGITUDE = -176

LATITUDE = -56

LATITUDE = -18

LATITUDE = 1

LONGITUDE = 161

M 5.7 - Jun 4, 2008, Japan region
M 5.7, Hokkaido, Japan region

M 4.2 - Oct 7, 2010, eastern Sea of Japan
M 4.2, eastern Sea of Japan

LONGITUDE = 151

LONGITUDE = 145

M 4.3 - Aug 13, 2010, Sea of Japan

M 6.0 - Feb 13, 2000, eastern Russia-northeastern China border region
M 6.0, eastern Russia-northeastern China border region

M 7.3, Jilin-Heilongjiang border region, China

M 5.9 - Sep 16, 2006, Sea of Japan

M 6.3, Primor'ye, Russia

Volcans du monde (Holocène)
Smithsonian Institution National Museum of Natural History NMNH
http://www.volcano.si.edu/

West Indies

Saba
Volcano types:
Stratovolcano
Lava domes
Summit Elev: 887 m
Latitude: 17.63°N
Longitude: 63.23°W
Saba, the northernmost active volcano of the West Indies, is a small 5-km-diameter island forming the upper half of a large stratovolcano that rises 1500 m above the sea floor. Its eruptive history is characterized by the emplacement of lava domes and associated pyroclastic flows. The summit of the volcano, known as Mount Scenery (or The Mountain), is a Holocene lava dome that overtops a major collapse scarp that formed about 100,000 years ago. Flank domes were constructed on the SW, SE, east, and NE sides of the island near the coast. A large andesitic lava flow entered the sea on the NE flank, forming the Flat Point Peninsula, the only site level enough on which to locate the island's airport. The village of The Bottom overlies pyroclastic-surge deposits that contain European pottery fragments and were radiocarbon dated at 280 +/- 80 years before present. The village was settled in 1640 on grassy meadows on the volcano's flanks reflecting initial vegetation recovery following destruction of tropical rainforests by pyroclastic flows and surges. Lava dome growth may also have occurred during this SW-flank eruption.
About Volcano Data | Larger photo with caption and credit.
Smithsonian Volcano Information | Seismic Research Unit, Univ. West Indies

The Quill
Statia
Volcano types:
Stratovolcano
Lava dome
Summit Elev: 601 m
Latitude: 17.478°N
Longitude: 62.960°W
The Quill is a large dominantly andesitic stratovolcano that forms the SE end of St. Eustatius (Statia) Island. The 601-m-high volcano was formed about 32,000-22,000 years ago by rhyolitic eruptions on a shallow-water limestone bank 3 km offshore of an older 0.2 million years old volcanic center exposed at the NW end of the island. The interaction of rhyolitic magma with sea water produced pyroclastic-surge deposits, rich in limestone fragments, that joined the two islands and blanket the entire slopes of The Quill. The surges also swept across the older island and incorporated carbonized plant remains, shell fragments, and remains of fossil hermit crabs. A likely cryptodome tilted up limestones at Sugarloaf on the southern coast. A steep-sided crater, 760 m wide and more than 300 m deep caps The Quill; a notch on the western rim of the crater has directed the youngest pyroclastic flows towards the island's capital, Orangestad. The last dated eruption of The Quill produced pyroclastic flows about 1600 years ago.
About Volcano Data | Larger photo with caption and credit.
Smithsonian Volcano Information | Seismic Research Unit, Univ. West Indies

Liamuiga
St. Kitts
Volcano types:
Stratovolcano
Lava domes
Summit Elev: 1156 m
Latitude: 17.37°N
Longitude: 62.80°W
Mount Liamuiga volcano, comprising the NW end of St. Kitts Island, contains a steep-walled, 1-km-wide summit crater, which contained a shallow lake until 1959. Two lava domes are located on the upper western flank, and intrusion of a 3rd dome, Brimstone Hill, on the lower SW flank uplifted a Pleistocene limestone block. Liamuiga volcano (sometimes referred to as Mount Misery) is the youngest of 3 NW-migrating volcanic centers on St. Kitts. Its most recent major eruptions less than 2000 years ago produced pyroclastic flows and mudflows whose deposits underlie populated coastal areas. Reports of possible historical eruptions in 1692 and 1843 are considered uncertain. An earthquake swarm occurred from late 1988 to early 1989, causing small landslides in the summit crater; another earthquake swarm took place in 1999-2000. Active fumaroles are found in the summit crater of Liamuiga.
About Volcano Data | Larger photo with caption and credit.
Smithsonian Volcano Information | Seismic Research Unit, Univ. West Indies

Nevis Peak
Nevis
Lava domes
The conical island of Nevis, lying across a narrow channel from St. Kitts (St. Christopher) Island, is a composite cone with overlapping summit craters. An unnamed lava dome is located NE of the rims of the two craters. Nevis Peak, the 985 m high point of the island, is located on the outer crater rim. The inner crater truncates the western rim of the earlier crater and is widely breached on the west side. A small lava dome was emplaced within the inner crater in recent pre-Columbian time, and pyroclastic flows and mudflows were deposited on the lower slopes of the cone. Four lava domes were constructed on the flanks of the volcano. Madden's Mount and Butlers Mountain were built on the NE and eastern flanks, respectively; Mount Lily lies on the NW coast and Saddle mountain on the southern coast. No historical eruptions are known from Nevis, and the youngest dated eruption was about 100,000 years ago. Active fumaroles and hot springs are found on the island (the most recent of these formed in 1953 and remains active), and seismic swarms have occurred on several occasions during the 20th century.

Soufrière Hills
Montserrat
The complex, dominantly andesitic Soufrière Hills volcano occupies the southern half of the island of Montserrat. The summit area consists primarily of a series of lava domes emplaced along an ESE-trending zone. English's Crater, a 1-km-wide crater breached widely to the east, was formed during an eruption about 4000 years ago in which the summit collapsed, producing a large submarine debris avalanche. Block-and-ash flow and surge deposits associated with dome growth predominate in flank deposits at Soufrière Hills. Non-eruptive seismic swarms occurred at 30-year intervals in the 20th century, but with the exception of a 17th-century eruption that produced the Castle Peak lava dome, no historical eruptions were recorded on Montserrat until 1995. Long-term small-to-moderate ash eruptions beginning in that year were later accompanied by lava-dome growth and pyroclastic flows that forced evacuation of the southern half of the island and ultimately destroyed the capital city of Plymouth, causing major social and economic disruption.
Smithsonian Volcano Information | Montserrat Volcano Observatory

Bouillante Chain
Guadeloupe
Maars
The Bouillante Chain along the west-central coast of Basse Terre consists of a N-S-trending chain of phreatomagmatic craters and offshore submarine cones that were active about 0.8-0.25 million years ago (Komorowski et al., 2005). The Bouillante geothermal field and numerous submarine hot springs attest to its recent activity.
About Volcano Data |
Smithsonian Volcano Information

Soufrière Guadeloupe
Guadeloupe
La Soufrière de la Guadeloupe volcano occupies the southern end of Basse-Terre, the western half of the butterfly-shaped island of Guadeloupe. Construction of the Grand Découverte volcano about 0.2 million years ago (Ma) was followed by caldera formation after a plinian eruption about 0.1 Ma, and then by construction of the Carmichaël volcano within the caldera. Two episodes of edifice collapse and associated large debris avalanches formed the Carmichaël and Amic craters about 11,500 and 3100 years ago, respectively. The presently active La Soufrière volcano subsequently grew within the Amic crater. The summit consists of a flat-topped lava dome, and several other domes occur on the southern flanks. Most historical eruptions have originated from NW-SE-trending fissure systems that cut across the summit and upper flanks. A relatively minor phreatic eruption in 1976-77 caused severe economic disruption when Basse-Terre, the island's capital city, which lies immediately below the volcano, was evacuated.
Smithsonian Volcano Information | IPGP Observatoire Volcanologique et Sismologique de Guadeloupe

Morne aux Diables
Dominica
The relatively unknown 861-m-high Morne aux Diables (Devils' Peak) stratovolcano forms the northern tip of the island of Dominica. Several nested craters and a 90-m-high, 335-m-wide lava dome are located within a larger 1.2-km-wide crater. A chain of lava domes, two of which form a peninsula on the SW flank, form an E-W belt across the southern flank of the volcano. Bathymetry shows a double-peaked lava dome (known informally as Twin Peaks) off the northern coast, which is truncated by a 4-km-long fault-bounded cliff. No eruptions are known from Morne aux Diables in historical time, although the volcano has a youthful appearance and activity at flank domes likely continued into the late-Pleistocene and Holocene. The youngest (NW) summit crater contains an active thermal area with bubbling springs. Severe earthquake swarms in 1841 and 1893 were associated with either Morne aux Diables or Morne Diablotins to the south.

Morne Diablotins
Dominica
Summit Elev: 1430+ m
Morne Diablotins, a relatively unknown volcano in northern Dominica, is the largest and highest on Dominica and the second highest peak of the Lesser Antilles. A complex of at least five coalescing lava domes forms the broad summit of roughly 1430-m-high Morne Diablotins, and other domes are found to the SE. Pyroclastic-flow deposits emplaced about 22,000-40,000 years ago, known as the Grand Savanne Ignimbrite, extend in five radial tongues around the volcano as far as the coast. Precolumbian block-and-ash flow aprons on the NW flank are relatively unmodified by erosion. No historical eruptions are known from Morne Diablotins, although numerous hot springs, both onshore and submarine, are found near Glanvillia, on the NW flank. Severe earthquake swarms in 1841 and 1893 originated either from Morne Diablotins or Morne aux Diables to the north.

Morne Trois Pitons
Dominica
Complex volcano
Caldera
Two large lava-domes complexes, Morne Trois Pitons and Micotrin, rise NE of the capital city of Roseau in central Dominica. Micotrin (Morne Macaque) dome lies immediately south of the larger 1387-m-high Morne Trois Pitons; small lakes are located in the saddle between the two domes and on the eastern flank of Micotrin. The domes are located along the margin of a large semi-circular depression on the western coast of central Dominica, whose origin has been variously attributed to caldera collapse, gravity sliding, or the juxtaposition of several independent volcanic centers. The area is the source of the voluminous, mostly submarine Roseau Tuff, a thick sequence of pyroclastic flows erupted between about 40,000 and 25,000 years ago. It is considered to have originated from calderas at Morne Trois Piton and Wotten Waven, the latter an elliptical NE-SW-trending caldera containing Microtin at its NE end. Explosive eruptions at the Trois Piton-Microtin complex producing pyroclastic flows continued into the late Pleistocene and Holocene. The youngest dated eruption took place about 800 AD, but other smaller eruptions may have occurred since.

Morne Watt
Stratovolcanoes
Morne Watt (Watt Mountain) volcano lies SE of the Trois Piton/Micotrin lava-dome complex in SE Dominica, east of the capital city of Roseau. The two best-known volcanic features on Dominica, the Valley of Desolation and the Boiling Lake thermal areas, lie on the flank of Morne Watt; both are major tourist attractions within the national park on Dominica. Morne Anglais stratovolcano lies 4 km SW of Morne Watt and Grand Soufrière Hills volcano, with dated pyroclastic-flow producing eruptions about 10,000 years ago, lies 3 km to the east. A major eruption from Morne Watt producing pyroclastic flows took place about 1300 years ago. A moderately large phreatic explosion took place at the Valley of Desolation thermal area NE of Morne Watt in 1880, when ash fell over a 4-km-wide sector at the coast, 10 km from the vent. A smaller phreatic explosion occurred in July 1997, when ashfall was confined to the Valley of Desolation area. These mark the only known historical eruptions on the island of Dominica.

Morne Plat Pays
Caldera
The Morne Plat Pays volcanic complex occupies the southern tip of the island of Dominica and has been active throughout the Holocene. An arcuate caldera that formed about 39,000 years ago as a result of a major explosive eruption and flank collapse is open to Soufrière Bay on the west. This depression cuts the SW side of Morne Plat Pays stratovolcano and extends to the southern tip of Dominica. At least a dozen small post-caldera lava domes were emplaced within and outside this depression, including one submarine dome south of Scotts Head. The latest dated eruptions at the Morne Plat Pays complex occurred from the Morne Patates lava dome about 1270 AD, although younger deposits have not yet been dated. The Morne Plat Pays complex is the site of extensive fumarolic activity, and at least ten swarms of small-magnitude earthquakes, none associated with eruptive activity, have occurred since 1765 at Morne Patates.

Pelée
Martinique
Calderas
Renowned Montagne Pelée, forming the northern end of the island of Martinique, is the most active volcano of the Lesser Antilles arc. Three major edifice failures since the late Pleistocene, the last about 9000 years ago, have left large horseshoe-shaped calderas breached to the SW inside which the modern volcano has been constructed. More than 20 major eruptions have occurred at Pelée during the past 5000 years. Extensive pyroclastic-flow deposits, incised by steep-walled ravines, mantle the slopes of the volcano. The l'Etang Sec summit crater is filled by two lava domes emplaced during the 1902 and 1929 eruptions. Historical eruptions date back to the 18th century; only two modest phreatic or phreatomagmatic eruptions took place prior to 1902. The catastrophic 1902 eruption, which destroyed the city of St. Pierre, the "Pearl of the Lesser Antilles," became the type-example of pelean eruptions and marked the onset of modern volcanological studies of the behavior of pyroclastic flows.
Smithsonian Volcano Information | IPGP Observatoire Volcanologique de la Montagne Pelée

Qualibou
St. Lucia
Caldera
Tuff rings
The Qualibou caldera on the SW side of St. Lucia provides the setting for the Pitons, two steep-sided pre-caldera lava domes that form one of the scenic highlights of the West Indies. The 3.5 x 5-km-wide Qualibou caldera formed about 32-39,000 years ago in conjunction with the eruption of the Choiseul Tuff. A larger depression has been interpreted to have formed by edifice collapse, and bathymetry has identified large submarine debris-avalanche deposits off the west coast of the island. This depression and associated volcanic vents and geothermal areas is also known as the Soufrière volcanic centre. Numerous resurgent post-caldera lava domes fill the caldera floor. The latest dated magmatic eruptions took place about 20,000 years ago, but younger undated lava domes and explosion craters are present. The only known Holocene eruptive activity was a minor phreatic eruption in the Sulfur Springs geothermal area in 1766 AD that ejected a thin ash layer over a wide area. A volcanic earthquake swarm centered 6 km ESE of the caldera occurred in 1990.

Soufrière St. Vincent
St. Vincent
Lava dome
Soufrière St. Vincent is the northernmost and youngest volcano on St. Vincent Island. The 1.6-km wide summit crater, whose NE rim is cut by a crater formed in 1812, lies on the SW margin of the 2.2-km-wide Somma crater, which is breached widely to the SW as a result of slope failure. Frequent explosive eruptions since about 4300 years ago produced pyroclastic deposits of the Yellow Tephra Formation, which blanket much of the island. The first historical eruption of the volcano took place during 1718; it and the 1812 eruption produced major explosions. Much of the northern end of the island was devastated by a major eruption in 1902 that coincided with the catastrophic Mont Pelée eruption on Martinique. A lava dome was emplaced in the summit crater in 1971 during a strictly effusive eruption, forming an island in a lake that filled the crater prior to an eruption in 1979. The lake was then largely ejected during a series of explosive eruptions, and the dome was replaced with another.

Kick 'em Jenny
Grenada-N of
Submarine volcano
Tuff cones
Summit Elev: -185 m
Kick 'em Jenny, a historically active submarine volcano 8 km off the north shore of Grenada, rises 1300 m from the sea floor. Recent bathymetric surveys have shown evidence for a major arcuate collapse structure that was the source of a submarine debris avalanche that traveled more than 15 km to the west. Bathymetry also revealed another submarine cone to the SE, Kick 'em Jack, and submarine lava domes to its south. These and subaerial tuff rings and lava flows at Ile de Caille and other nearby islands may represent a single large volcanic complex. Numerous historical eruptions, mostly documented by acoustic signals, have occurred at Kick 'em Jenny since 1939, when an eruption cloud rose 275 m above the sea surface. Prior to the 1939 eruption, which was witnessed by a large number of people in northern Grenada, there had been no written mention of Kick 'em Jenny. Eruptions have involved both explosive activity and the quiet extrusion of lava flows and lava domes in the summit crater; deep rumbling noises have sometimes been heard onshore. Historical eruptions have modified the morphology of the summit crater.

St. Catherine
Grenada
Explosion craters
The island of Grenada is composed of five Pliocene-to-Pleistocene volcanic centers, the youngest and highest of which is Mount St. Catherine on the northern end of the island. A complex of lava domes is located within a horseshoe-shaped crater breached to the east at the summit of 840-m-high Mount St. Catherine. Pyroclastic-flow deposits extend to the NW from the extensively weathered volcano. The most recent activity on Grenada originated from a group of young maars, tuff rings, and scoria cones that extend SSW-NNE across the length of the 30-km-long island. Kick 'em Jenny, the historically active submarine volcano 8 km north of Grenada, is listed separately in this compilation along with adjacent submarine and subaerial cones that may represent a single volcanic complex. No eruptions of St. Catherine are known in historical time, although the most recent eruption along a NE-SW-trending fault cutting across the island produced a scoria cone near Radix village that could be less than 1000 years old. Hot springs and fumaroles are present at several locations on Mount St. Catherine.

México and Central America

México

Cerro Prieto
Northwestern México
Lava dome
The Cerro Prieto geothermal field is located at the head of the Gulf of California, 35 km south of the city of Mexicali. Cerro Prieto lies in an active continental rift that is transitional between the transform San Andreas fault system to the north and a spreading ridge of the East Pacific Rise in the Gulf of California to the south. The only surficial volcanic feature at Cerro Prieto, which is located near sea level on the Colorado River delta, is a small, 223-m-high compound dacitic lava dome. A 200-m-wide crater is located at the summit of the NE-most dome. The Cerro Prieto dome was roughly estimated from paleomagnetic evidence to have formed during a series of events between 100,000 and 10,000 years ago. Cucupas Indian legends described a monster that covered the land with hot rocks, which grew through the soil and emitted fire tongues, a possible reference to the growth of the volcano.
Smithsonian Volcano Information | CENAPRED, México

Pinacate
Northwestern México
Cinder cones
Maars
Tuff rings
Summit Elev: 1200+ m
Pinacate is a large, roughly 55 x 60 km volcanic field in the Sonoran desert of NW México. It contains numerous youthful maars, tuff rings, and cinder cones of late-Pleistocene to Holocene age. The 2000 sq km volcanic field is prominent in satellite images of this arid, sparsely populated region between the Arizona border and the head of the Gulf of California. An older volcanic episode constructed the 1200-m-high Santa Clara basaltic-to-trachytic shield volcano. This was followed by the eruption of more than 500 basaltic cinder cones and lava flows that blanket the slopes of Santa Clara and the surrounding desert. Among the principal features of the Pinacate volcanic field are Elegante crater, a 1.6-km-wide maar, and Cerro Colorado, a 110-m-high, 1.1-km-wide tuff ring. Papago (Tohono O'odham) Indian legends tell of eruptions, however historical accounts of ash-and-steam eruptions in the 20th century are questionable.
Smithsonian Volcano Information | CENAPRED, México

San Quintín Volcanic Field
Baja California (México)
Cinder cones
Summit Elev: 260+ m
San Quintín volcanic field on the NW coast of Baja California consists of 11 late-Pleistocene to Holocene volcanic complexes. Low lava shields, initially submarine, are capped by well-preserved scoria cones. San Quintín rocks are similar to intraplate or oceanic island alkalic rocks and differ from other Baja alkalic volcanic suites. San Quintín is the only Quaternary volcanic field in Baja California where lower-crustal and upper-mantle xenoliths are found. The field is located at the margins of the Y-shaped San Quintín Bay and includes a northern and southern group of cones, Monte Mazo (connected to the mainland by a long tombolo), and Isla San Martín, 5 km offshore to the west. The youngest craters overlie deposits thought to be dated at 5-6000 years before present, and Gastil et al. (1975) considered the southern cones of Vizcaino and Sudoeste to possibly be less than 3000 years old. However, later Argon/Argon dating (Ortega-Rivera et al., 2004) restricted eruptions to a range of between about 20,000 to 180,000 years ago.
Smithsonian Volcano Information | CENAPRED, México

Isla San Luis
Baja California (México)
Tuff cone
Tuff rings
Summit Elev: 180? m
Isla San Luis is the largest of the seven Encantada islands at the NW end of the Guaymas lineament in the northern part of the Gulf of California. The roughly 180-m-high island (also known as La Encantada Mayor, or Salvatierra) is located 3 km off the eastern shore of Baja California north of Punta Bufeo. The small 4.5 sq km island has an irregular shoreline with a narrow peninsula forming its SW tip. Initial basaltic-andesite and andesitic submarine surtseyan eruptions producing palagonite tuffs were followed by the effusion of subaerial dacitic lava flows and the formation of dacitic tuff rings. The latest eruptions formed two rhyolitic obsidian domes, the younger in a tuff cone at the center of the island and at the older at the NW tip of the island. Although the age of the domes is not known precisely, Medina et al. (1989) suggested that they could be less than a century old.

Jaraguay Volcanic Field
Baja California (México)
Cinder cones
Summit Elev: 960? m
The Jaraguay volcanic field is the northernmost of a group of large young alkalic volcanic fields in Baja California. Located primarily on the Pacific Ocean side of northern Baja between Jaraguay and Arroyo San José, the Jaraguay field contains numerous youthful-looking cinder cones and associated basaltic and basaltic-andesite lava flows. Some lava flows are less vegetated than flows of the San Quintín volcanic field to the north that overlie 5000-6000 year-old midden deposits (Rogers et al., 1985). Several Holocene lava flows were erupted near the south side of Arroyo San José at the SW end of the Jaraguay volcanic field.

Coronado
Volcán Coronado is a small stratovolcano at the northern tip of Coronado Island, 3 km off the eastern coast of Baja California in the Canal de los Ballenas. The roughly 440-m-high volcano forms a 2-km-wide peninsula at the northern end of the elongated NNW-SSE-trending island and contains a 300 x 160 m wide crater. The age of the most recent eruptive activity from Volcán Coronado is not known, although fumarolic activity was reported in September 1539 (Medina et al., 1989).

Guadalupe
W of Baja California (México)
Shield volcano
Elongated Guadalupe Island lies atop a fossil oceanic ridge crest about 300 km west of Baja California. The seamount, which rises above the Pacific Ocean surface to an elevation of 1100 m, contains two shield volcanoes, the northern of which is the youngest. Chains of cinder cones constructed along fissures oriented both NW-SE and NE-SW and associated lava flows overlie both shield volcanoes. The longest of these fissures cuts across the caldera of the northern volcano and extends beyond it to the SE. Other pyroclastic cones were constructed along an arcuate fissure near the southern caldera rim. The shield volcanoes and products of the fissure eruptions form a complete alkali basaltic-to-trachytic series reflecting a transition from submarine to subaerial volcanism. The 1100-m-high northern basaltic shield volcano was considered to be of Holocene age (Medina et al. 1989). Trachytic lava domes are found within the caldera of the northern shield volcano, and together with very fresh-looking alkali basalt lava flows, form the youngest volcanic rocks on the island.

San Borja Volcanic Field
The San Borja volcanic field, also known as the El Rosarito volcanic field, is located in central Baja California NE of the Vizcaino Peninsula. Holocene lava flows occur at Rosarito and Morro San Domingo at the western end of the San Borja volcanic field along the coast north of the Vizcaino Peninsula. Some lava flows of the San Borja volcanic field are less vegetated than flows of the San Quintín volcanic field to the north that overlie 5000-6000 year-old midden deposits (Rogers et al., 1985). The Holocene lava flows in the western part of this alkalic volcanic field are of basaltic-andesite and andesitic composition.

El Aguajito
México-Baja Calif
El Aguajito caldera (also known as Santa Ana caldera) is located along the Gulf of California immediately NE of Tres Vírgenes volcano and NW of La Reforma caldera. The rim of the approximately 10-km-wide resurgent caldera is not exposed, but an arcuate line of andesitic-to-rhyolitic lava domes covers its northern margin. Formation of the rhyolitic caldera was associated with the eruption of ignimbrites, K-Ar dated at 0.76 +/- 0.06 million years ago (Ma), most of which were deposited in the Gulf of California. Rhyolitic lava domes on the northern margin have been dated at 0.5 +/- 0.04 Ma; dacitic lava domes on the southern side of the caldera appear to be older. The regional NNE-SSW-trending Cimarron fault cuts across the center of the caldera. Hot springs are located along the southern caldera margin, and active seismicity was noted during geothermal exploration.
Smithsonian Volcano Information

Tres Vírgenes
Stratovolcanoes
Pyroclastic cones
The Tres Vírgenes volcanic complex contains the only large stratovolcanoes in Baja California. The roughly 1940-m-high complex rises above the Gulf of California in the east-central part of the peninsula. Three volcanoes, El Viejo, El Azufre, and La Vírgen were constructed along a NE-SW line and are progressively younger to the SW. The youngest volcano, La Vírgen, is an andesitic stratovolcano with numerous dacitic lava domes and lava flows on its flanks. A major plinian explosive eruption from a SW-flank vent was radiocarbon dated at about 6500 years ago, but Helium exposure and Uranium-series dates give a late-Pleistocene age for this event. An ash plume was reported from Tres Vírgenes volcano by a Spanish Jesuit priest while navigating the Gulf of California in 1746. No tephra deposits from such a young eruption have been found, but young undated andesitic lava flows at the summit could potentially be related to this event. A geothermal plant is located at the northern end of the complex near the margin of the Pleistocene El Aguajito caldera.

Isla Tortuga
Shield volcano
A youthful shield volcano forms Isla Tortuga, which lies in the Gulf of California 40 km off the Baja coast. A circular, 1-km-wide caldera, west of the center of the oval, 4-km-long island, truncates the small shield volcano, which reaches only about 210 m above sea level. Circumferential faults cut the rim of the >100-m-deep caldera, which is floored by a solidified lava lake and contains youthful-looking spatter cones. The shield volcano was constructed during two north-migrating periods of activity that began with submarine eruptions and included formation of a circular tuff-ring complex enclosing the caldera. The sides of a small volcanic horst in the center of the caldera display lava flows overlying a 2-m-thick halite bed, formed when sea water filled the caldera, creating an evaporite basin. Recent lava flows cover most of the flanks of the volcano, and fumarolic activity has continued into historical time.

Punta Púlpito
México
Punta Púlpito is a Pleistocene obsidian dome dated at about 0.5 million years that forms a small peninsula along the Gulf of California, east of the southern tip of Bahía Concepción in southern Baja California. The Saquicismunde geothermal area with hydrothermal springs and steaming ground lies close to the dome, and the larger Los Volcanes geothermal area, lying along the coast about 5 km south of Punta el Púlpito, contains 18 fumaroles along a NW-SE alignment.
Smithsonian Volcano Information

Comondú-La Purísima
Volcanic field
The Comondú-La Purísima volcanic field, located in southern Baja California, west of the Sierra de la Giganta, dates back to the Miocene. However, the youthful morphology of some cinder cones suggested possible Holocene ages (Sawlan, 1991). The youngest lavas form blocky flows with flow ridges and are mostly located in the area between Comondú and the La Purísima river. Vents usually occur along NNW-trending faults, and many lava flows are offset, sometimes repeatedly, along grabens. Both basaltic and andesitic lava flows are present. The former are typically 5-10 m thick, and the latter are up to 60-80 m thick and form dense, glassy flows with subhorizontal fractures.

Bárcena
Revillagigedo Islands (México)
Volcán Bárcena, formed by eruptions during 1952-53, is the most prominent feature of Isla San Benedicto, the NE-most of the Revillagigedo Islands, 350 km south of the tip of Baja California. San Benedicto island, elongated in a NE-SW direction, contains a series of Pleistocene trachytic lava domes at the north end. The southern end of the 4.5-km-long island is formed by Bárcena and Montículo Cinerítico, a smaller tephra cone that preceded and was largely overtopped by Bárcena. Montículo Cinerítico may also have been constructed during the past few hundred years and formed the high point of the island prior to the formation of Bárcena. Growth of the 300-m-high Bárcena tephra cone beginning in August 1952 was accompanied by strong explosive eruptions and pyroclastic flows. The eruption concluded the following year with the emplacement of two small lava domes in the crater and extrusion of a prominent coastal lava delta at the SE base of the cone.

Socorro
Revillagigedo Islands (México)
Shield volcano
Socorro, the SE-most of the Revillagigedo Islands south of Baja California, is the summit of a massive, predominately submarine basaltic shield volcano capped by a largely buried, 4.5 x 3.8-km-wide summit caldera. A large tephra cone and lava dome complex, Cerro Evermann, forms the 1050-m-high summit of the volcano, and along with other cones and vents, fills much of the Pleistocene caldera. Rhyolitic lava domes have been constructed along flank rifts oriented to the north, west, and SE, and silicic lava flows from summit and flank vents have reached the coast and created an extremely irregular shoreline. Late-stage basaltic eruptions produced cones and flows near the coast. Only minor explosive activity, some of which is of uncertain validity, has occurred from flank vents in historical time dating back to the 19th century. In 1951 a brief phreatic eruption ejected blocks, and the gas column reached 1200 m elevation. A submarine eruption occurred during 1993-94 from a vent 3 km west of the island during which large scoriaceous blocks up to 5 m in size floated to the surface without associated explosive activity.

Durango Volcanic Field
México
Maars
The broad Durango volcanic field covers 2100 sq km at the NW corner of the Meseta Central near the eastern edge of the Sierra Madre Occidental of north-central México. The expansive undissected lava plain lies within the Mexican Basin and Range province and is located NE of the city of Durango. The Durango volcanic field is dotted with about 100 Quaternary basanitic cinder and lava cones as well as several important xenolith localities. La Breña-El Jagüey maar complex consists of two intersecting maars, the largest of which (La Breña) contains a series of nested cinder cones. The maar complex is one of the youngest eruptive centers of the Durango volcanic field and was considered by Aranda-Gómez et al. (1992) to be only a few thousand years old.

Sangangüey
Pyroclastic cones
Sangangüey, the highest volcano of the NW-SE-trending Tepic-Zacoalco graben, is an eroded andesitic and dacitic stratovolcano that contains a prominent lava spine at its summit. The NW and SE flanks of the Pleistocene edifice of Volcán Sangangüey are dotted with 45 cinder cones that erupted during the past 300,000 years along 5 parallel lines. Some of the cinder cones appear morphologically similar to cones on nearby Ceboruco volcano that are known to be less than 1000 years old. There are no confirmed historical eruptions from Sangangüey. An incorrect report of an eruption in 1859 from San Juan (a synonym of Sangangüey) refers to the nearby Pleistocene San Juan volcano. An Indian tradition records an eruption of Sangangüey in 1742 (Sapper, 1917). If these legends are true, they may refer to an eruption from one of the young flank cinder cones of Sangangüey.

Ceboruco
Volcán Ceboruco is the only historically active volcano in the NW part of the Mexican Volcanic Belt. The complex stratovolcano rises above the floor of the Tepic graben and is truncated by two concentric summit calderas. Eruption of the voluminous rhyodacitic Jala Pumice, the largest known in México during the Holocene, formed the initial 4-km-wide caldera about 1000 years ago. The second caldera, 1.5 km wide, was formed by collapse of part of the large Dos Equis dacitic lava dome, which partly filled the earlier caldera. About 15 basaltic and andesitic cinder cones and lava flows have erupted along a NW-SE-trending line cutting across Ceboruco. The massive, sparsely vegetated El Norte lava flow, probably erupted in the past few hundred years, blankets the entire northern flank of the volcano. The last eruption of Ceboruco took place during 1870-75. Explosive eruptions from a vent on the upper west flank accompanied extrusion of a 1.1 cu km dacitic lava flow that covers a large area on the lower western flank.

Mascota Volcanic Field
A group of calc-alkaline andesitic and minette cinder cones and lava domes, both with associated lava flows, is located near the town of Mascota, in the Jalisco tectonic block about 50 km east of Puerto Vallarta. Mascota is the youngest of a group of potassic volcanic fields in extensional grabens of the Jalisco block south of the Río Ameca. Most volcanism in the Mascota volcanic field is confined to two NNW-SSE-trending grabens cutting Cretaceous ash-flow tuffs. The youngest eruption, at Volcán Malpaís, north of Mascota, produced a fresh-looking basaltic-andesite lava flow. The lack of soil development and sparse vegetation suggest that it may be only a few thousand years old (Carmichael et al., 1996). The volcanic field is noted for its unusual diversity of volcanic rocks, and Mascota contains Earth's youngest known minettes, with radiometric ages down to 0.07 +/- 0.08 million years.

Sierra la Primavera
The Sierra la Primavera volcanic complex is located immediately west of México's second-largest city, Guadalajara. Following the eruption of rhyolitic lava flows and domes beginning about 120,000 years before present (BP), an 11-km-wide caldera was formed as a result of the eruption of the 20 cu km Tala Tuff about 95,000 years BP. La Primavera caldera subsequently filled with water, forming a lake, through which several lava domes were emplaced. The eruption of a series of older ring domes along the margin of the caldera about 95,000 years ago was followed about 75,000 years ago by the eruption of a younger series of ring domes. Uplift and sedimentation filled the lake, and a final series of lava domes was erupted along the southern margin of the caldera beginning about 60,000 years BP. The youngest lava dome was dated at about 30,000 years BP. Steam vents and hot springs currently are active throughout the volcanic complex.

Colima
Stratovolcanoes
Calderas
The Colima volcanic complex is the most prominent volcanic center of the western Mexican Volcanic Belt. It consists of two southward-younging volcanoes, Nevado de Colima (the 4320 m high point of the complex) on the north and the 3850-m-high historically active Volcán de Colima at the south. A group of cinder cones of late-Pleistocene age is located on the floor of the Colima graben west and east of the Colima complex. Volcán de Colima (also known as Volcán Fuego) is a youthful stratovolcano constructed within a 5-km-wide caldera, breached to the south, that has been the source of large debris avalanches. Major slope failures have occurred repeatedly from both the Nevado and Colima cones, and have produced a thick apron of debris-avalanche deposits on three sides of the complex. Frequent historical eruptions date back to the 16th century. Occasional major explosive eruptions (most recently in 1913) have destroyed the summit and left a deep, steep-sided crater that was slowly refilled and then overtopped by lava dome growth.
Smithsonian Volcano Information | Colima Volcano Observatory | CENAPRED, México (in Spanish)

Michoacán-Guanajuato
Shield volcanoes
The widespread Michoacán-Guanajuato volcanic field contains over 1400 vents, including the historically active cinder cones of Parícutin and Jorullo, covering a 200 x 250 km wide area of Michoacán and Guanajuato states in west-central México. Cinder cones are the predominant volcanic form, but small shield volcanoes, lava domes, maars and tuff rings (many in the Valle de Santiago area), and coneless lava flows are also present. The shield volcanoes are mostly Pleistocene in age, and have morphologies similar to small Icelandic-type shield volcanoes, although the Michoacán-Guanajuato shields have higher slope angles and smaller basal diameters. Jorullo, which was constructed in the 18th century, and Parícutin, which grew above a former cornfield during 1943-52, are the two best known of the roughly 1000 small volcanic centers scattered throughout the volcanic field.

Los Azufres
The Los Azufres volcanic center is one of several silicic volcanic complexes with active geothermal systems that lie north of the axis of the Mexican Volcanic Belt. Located about 200 km NW of Mexico City, the Los Azufres center consists of a 18 x 20 km wide early Pleistocene caldera that was later partially filled by resurgent dacitic-to-rhyolitic lava domes. Two magmatic cycles lasting about 200,000 years each took place between 1.4 and 0.8 Ma (million years), consisting of silicic, followed by basaltic volcanism. The latest magmatic cycle, beginning about 0.6 Ma, involved resurgent doming of the southern part of the caldera, the eruption of chemically diverse basaltic-to-rhyolitic products, and the emplacement of dacitic-rhyolitic lava domes. The latest paroxysmal eruptions produced ignimbrites between 38,000 and 26,000 years ago. Hot springs and fumaroles are located along E-W-trending faults, and Los Azufres is an active producing geothermal field.

Zitácuaro-Valle de Bravo
Pyroclastic cones
The Zitácuaro-Valle de Bravo volcanic field in the central part of the Mexican Volcanic Belt consists of a broad region of shield volcanoes, lava domes, and cinder cones surrounding the city of Heroica de Zitácuaro. The Zitácuaro volcanic complex itself, located SE of the city, was constructed within the 30-km-wide Las Tres Chicas caldera of Miocene age, which later underwent three post-caldera episodes of intra-caldera lava dome resurgence and included the intrusion of dacitic central lava domes, the emplacement of pyroclastic flows, and the eruption of andesitic lava flows. The youngest dated activity at the complex produced La Dieta airfall deposit about 31,000 years ago, and persistent local seismicity continues at Zitácuaro. The Valle de Bravo area to the south contains dominantly andesitic lava domes and flows, many of which were erupted along regional faults. The youngest flows were erupted at the bottom of a fault-controlled canyon; the most recent of these, west of the Valle de Bravo lake, has been Argon-Argon dated at about 5200 +/- 2300 years, and morphology suggests a Holocene age for other cones.

Jocotitlán
Jocotitlán is an isolated composite volcano that rises 1300 m above the Toluca basin 60 km WNW of Mexico City. The 3900-m-high volcano was constructed during the Pleistocene of andesitic-to-dacitic lava flows. A major obsidian-bearing dacitic plinian eruption was followed by the emplacement of a dacitic lava-dome complex, accompanied by lava effusion, pumice-fall eruptions, and pyroclastic surges. The most prominent feature of the volcano is a horseshoe-shaped escarpment open to the NE that formed as a result of gravitational failure of the summit during the early Holocene. The resulting debris-avalanche deposit covers an 80 sq km area to the NE. Lava dome emplacement accompanied by pyroclastic flows and surges subsequently filled much of the avalanche scarp. The latest known eruption occurred about 700 years ago and produced block-and-ash flows and pyroclastic surges.

Nevado de Toluca
Nevado de Toluca, México's fourth highest peak, rises above the Toluca basin about 80 km west of Mexico City. The broad, complex andesitic-dacitic stratovolcano, also known by the Nahuatl Indian name Xinantécatl, has a 1.5-km-wide summit crater that is open to the east. A large dacitic lava dome in this crater separates two lakes, known as the lakes of the Sun and Moon. At least three major edifice collapses during the Pleistocene produced large debris-avalanche and lahar deposits that affected broad areas below the volcano. Four major explosive eruptions during the late Pleistocene produced widespread ashfall and pyroclastic-flow deposits at about 36,000, 21,700, 12,100, and 10,500 years ago, producing the Ochre and the Lower, Middle, and Upper Toluca Pumice deposits, respectively. Recent work has revealed evidence for at least one Holocene eruption, about 3300 years ago, that produced pyroclastic flows and surges.

Chichinautzin
Volcanic field
The massive Chichinautzin volcanic field covers a 90-km-long, E-W-trending area immediately south of Mexico City. The Sierra Chichinautzin, formed primarily of overlapping small cinder cones and shield volcanoes, creates a broad topographic barrier at the southern end of the Basin of Mexico that extends from the eastern flank of Nevado de Toluca to the western flank of Iztaccíhuatl volcano. The volcanic field contains more than 220 Pleistocene-to-Holocene monogenetic vents. The best-known eruption occurred about 1670 radiocarbon years ago from the Xitle scoria cone, NE of the Volcán Ajusco lava-dome complex, which at 3930 m forms the highest peak of the Sierra Chichinautzin. The Xitle eruption produced a massive basaltic tube-fed lava flow that covered agricultural lands as well as pyramids and other structures of Cuicuilco and adjacent prehispanic urban centers. The southern part of Mexico City and the National University of México lie atop the distal end of the 13-km-long lava flow.

Papayo
The 3600-m-high postglacial Papayo lava dome, constructed along the crest of the Sierra Nevada range, is dwarfed by its massive neighbor Iztaccíhuatl volcano, 15 km to the SW. Papayo has been the source of voluminous dacitic lava flows that have traveled about 10 km from the vent both to the WSW and ENE. The steep-sided Cerro Papayo dacitic lava dome, rising 230 m above the surrounding lava flows, marks the vent. The 84 sq km compound lava field has a volume of about 21 cu km and includes flows that traveled long distances in opposite directions into the Valley of Mexico and toward the Puebla basin. Papayo lavas overlie glacial moraines about 12,000 years old (Nixon 1989). On the western side the flows surround the glaciated late-Pleistocene lava and pyroclastic cone of Iztaltetlac.

Iztaccíhuatl
Iztaccíhuatl, the "Woman in White," presents the profile of a sleeping woman as seen from the Valley of Mexico. A series of overlapping cones constructed along a NNW-SSE line to the south of the Pleistocene Llano Grande caldera forms the summit ridge of the massive 450 cu km volcano. Andesitic and dacitic Pleistocene and Recent volcanism has taken place from vents at or near the summit of Volcán Iztaccíhuatl. Valley headwalls near the summit vent (El Pecho) are draped with flows and tuff beds post-dating an 11,000 years before present glaciation. The youngest vents are located at the summit and a depression at 5100 m along the summit ridge midway between El Pecho and Los Pies (White 1986). Nixon (1989) considered all summit lavas to be Pleistocene in age, but noted a postglacial dacitic vent on the south flank of Iztaccíhuatl, north of the saddle between it and Popocatépetl.

Popocatépetl
Volcán Popocatépetl, whose name is the Aztec word for smoking mountain, towers to 5426 m 70 km SE of Mexico City to form North America's 2nd-highest volcano. The glacier-clad stratovolcano contains a steep-walled, 400 x 600 m wide crater. The generally symmetrical volcano is modified by the sharp-peaked Ventorrillo on the NW, a remnant of an earlier volcano. At least three previous major cones were destroyed by gravitational failure during the Pleistocene, producing massive debris-avalanche deposits covering broad areas south of the volcano. The modern volcano was constructed to the south of the late-Pleistocene to Holocene El Fraile cone. Three major plinian eruptions, the most recent of which took place about 800 AD, have occurred from Popocatépetl since the mid Holocene, accompanied by pyroclastic flows and voluminous lahars that swept basins below the volcano. Frequent historical eruptions, first recorded in Aztec codices, have occurred since precolumbian time.

La Malinche
Tuff cones
La Malinche is an eroded stratovolcano, cut by deep canyons, that rises to 4461 m NE of the city of Puebla. Malinche occupies an isolated position between the Popocatépetl-Iztaccíhuatl and Orizaba-Cofre de Perote volcanic ranges. Much of the andesitic-dacitic volcano was constructed during the Pleistocene, and the summit exhibits evidence of glacial erosion. This volcano remains relatively unstudied, however, recent work has identified tephra layers of Holocene age that originated from Volcán la Malinche. Several tuff cones and explosion craters, at least one of Holocene age, are found on the flanks of the volcano; one of the most prominent of these is the Xalapaxco tuff cone complex on the lower NE flank. Holocene lahars from La Malinche associated with an eruption about 3100 years ago reached the Puebla basin and affected precolumbian settlements.

Serdán-Oriental
Tuff cones
The Serdán-Oriental is a broad closed basin at the eastern end of the Mexican Altiplano dotted with rhyolitic lava domes, tuff cones, tuff rings, lava flows, and scoria cones of late-Pleistocene to Holocene age. The basin, filled by extensive large lakes during the Pleistocene, is bounded by the Cofre de Perote-Orizaba range on the east and Los Humeros caldera to the north. The most prominent features of the Serdán-Oriental volcanic field are the twin Las Derrumbadas lava domes, surrounded by an apron of debris-avalanche deposits, and the sharp-peaked Cerro Pizarro lava dome at the northern end of the basin. Several of the tuff rings, such as Laguna Atexcac and Laguna Alchichica, are filled with scenic lakes. A major explosive eruption from a vent inferred to be buried within the basin produced the Quetzalapa plinian pumice-fall deposit roughly 20,000 years ago.

Los Humeros
Calderas
Scoria cones
Los Humeros is the easternmost of a series of silicic volcanic centers with active geothermal systems located north of the axis of the Mexican Volcanic Belt. The first major silicic eruption produced the 230 cu km Xáltipan Ignimbrite about 460,000 years before present (BP), which covered about 3500 sq km and resulted in formation of the 15 x 21 km Los Humeros caldera. The emplacement of post-caldera lava domes and eruption of the 40 cu km Faby Tuff about 240,000 years BP was followed by eruption of the Zaragoza Tuff about 100,000 years BP and formation of the nested 10-km-wide Los Potreros caldera. A third and much smaller caldera (El Xalapazco) was formed about 40,000-20,000 years BP. The most recent eruptions at Los Humeros produced extensive morphologically youthful basaltic lava flows that are undated, but are younger than a 20,000 years BP rhyolitic lava flow and could be in part of early Holocene age (Negendank et al., 1985). Hot springs and fumarolic activity continues at Los Humeros, which is a producing geothermal field, the second developed in the Mexican Volcanic Belt.

Los Atlixcos
Los Atlixcos, also known as Cerro el Abra, consists of a shield volcano topped by two large pyroclastic cones and associated lava fields at the eastern end of the Mexican Volcanic Belt along the Gulf of Mexico about 80 km NW of the city of Veracruz. The two pyroclastic cones, both known as Cerro los Atlixcos, lie along an E-W line about 2 km apart; both cones are breached to the east. A broad apron of basaltic lava flows extends primarily to the north and east, reaching as far as the coast. The extent of the lava shield is defined by the Río Santa Ana on the NE and the Río El Tecuán on the south. The youthful morphology of the cones caused Negendank et al. (1985) to consider them to be of Holocene age. Other pyroclastic cones of Quaternary age are located to the NW, and a group of cones and silicic lava domes of Tertiary-to-Quaternary age were constructed along the coast to the SE.

Naolinco Volcanic Field
The Naolinco volcanic field in the Sierra de Chiconquiaco range north of Jalapa (Xalapa), the capital city of the state of Veracruz, consists of a broad area of scattered Quaternary pyroclastic cones and associated dominantly basaltic lava flows. Late-Pleistocene to Holocene pyroclastic cones cover an E-W-trending area on both sides of the town of Naolinco de Victoria. The largest cone is 2000-m-high Cerro Acatlán, located NE of Naolinco de Victoria. This and other nearby cones have fed voluminous lava flows that traveled down regional gradients to the south and SE. The Coacoatzintla lava flow from the Rincón de Chapultepec scoria cone in the western part of the field was erupted about 3000 years ago and is the youngest flow of the Naolinco volcanic field.

Cofre de Perote
Shield volcanoes
Cofre de Perote is a massive Quaternary andesitic-dacitic shield volcano that anchors the NNE end of a volcanic chain extending southward to Pico de Orizaba (Citlaltépetl) volcano. Lava flows dominated in formation of the broad compound shield volcano, which is largely of Pleistocene age and is morphologically distinct from the steep-sided stratovolcanoes of the Mexican Volcanic Belt. Glaciation at the summit has left a steep-sided, box-like peak, which is sometimes referred to as the "Treasure Chest of Perote." A large compound escarpment formed in part by multiple edifice collapses cuts the eastern side of the volcano. Numerous monogenetic cinder cones, likely related to regional volcanism, were erupted through the flanks of Cofre de Perote volcano. A cluster of very youthful basaltic cinder cones is located on the NE flank, and young lava flows have traveled eastward to beyond the major city of Xalapa (Jalapa), the capital of the state of Veracruz. The youngest lava flow, from the compound El Volcancillo vent on the lower NE flank, was radiocarbon dated at about 900 years ago.

La Gloria
Volcanic field
A broad area of Quaternary volcanic rocks lies in a sparsely populated highland between Cofre de Perote and Las Cumbres volcanoes. Two large arcuate east-facing scarps of uncertain origin are the most prominent features of the La Gloria volcanic field, whose name originates from the town at its NW base. The complex is also known as the Desconocido-Tecomales volcanic field. Numerous pyroclastic cones, some of which have a youthful morphology, are scattered throughout the complex on both sides of the escarpments. The age of the most recent eruptions in this poorly studied region is not known, although some lava flows were classified by Negendank et al. (1985) as Holocene based on their youthful morphology.

Las Cumbres
The Las Cumbres volcanic complex, a Quaternary center about 15 km NNE of Pico de Orizaba, contains a 3.5-4.5 km wide summit caldera narrowly breached on the east side. A dacitic lava dome (Cerro Gordo or El Cumbre Grande) lies in the center of the caldera. A group of monogenetic cones, explosion craters, and andesitic and rhyolitic lava domes is located north and south of Cerro las Cumbres. Three of these, Xalista and El Rodeo to the north, and Ixetal to the south, are obsidian domes. A major rhyolitic explosive eruption producing the Quetzalapa Pumice about 20,000 years ago originated from a vent on the lower NW flank of the Las Cumbres complex. Eruptive activity at the main Las Cumbres complex ceased during the late Pleistocene, although activity on the flanks of the edifice continued into the Holocene. The rhyolitic Yolotepec lava dome, north of Las Cumbres, has been radiocarbon dated at about 5900 years before present.

Pico de Orizaba
Pico de Orizaba (Volcán Citlaltépetl), México's highest peak and North America's highest volcano, was formed in three stages beginning during the mid-Pleistocene. Orizaba lies at the southern end of a volcanic chain extending north to Cofre de Perote volcano and towers up to 4400 m above its eastern base. Construction of the initial Torrecillas and Espolón de Oro volcanoes was contemporaneous with growth of Sierra Negra volcano on the SW flank and was followed by edifice collapses that produced voluminous debris avalanches and lahars. The modern Citlaltépetl volcano was constructed during the late Pleistocene and Holocene of viscous andesitic and dacitic lavas, forming the current steep-sided cone. Repetitive explosive eruptions beginning during the early Holocene accompanied lava dome growth and lava effusion. Historical eruptions have consisted of moderate explosive activity and the effusion of dacitic lava flows. The latest eruption of the volcano occurred during the 19th century.

San Martín
Volcán de San Martín, part of the Tuxtla volcanic field, is a broad alkaline shield volcano that rises above the Gulf of Mexico. The massive volcano, also known as San Martín Tuxtla, is elongated in a NW-SE direction and is capped by a 1-km-wide summit crater. The upper part of the 1650-m-high volcano is covered with dense tropical rain forests. The summit and flanks of San Martín are dotted with more than 250 pyroclastic cones and maars. Well-preserved cinder cones are abundant between the summit of the volcano and Laguna Catemaco on the SE flank. Holocene cones in this area produced ash deposits that buried recently discovered stone pyramids. The two largest historical eruptions of San Martín took place in 1664 and 1793. The 1793 eruption occurred from two cinder cones in the summit crater and produced widespread ashfall and lava flows that extended 3.5 km down the NE flank.

El Chichón
Explosion crater
Summit Elev: 1150? m
El Chichón is a small, but powerful trachyandesitic tuff cone and lava dome complex that occupies an isolated part of the Chiapas region in SE México far from other Holocene volcanoes. Prior to 1982, this relatively unknown volcano was heavily forested and of no greater height than adjacent nonvolcanic peaks. The largest dome, the former summit of the volcano, was constructed within a 1.6 x 2 km summit crater created about 220,000 years ago. Two other large craters are located on the SW and SE flanks; a lava dome fills the SW crater, and an older dome is located on the NW flank. More than ten large explosive eruptions have occurred since the mid-Holocene. The powerful 1982 explosive eruptions of high-sulfur, anhydrite-bearing magma destroyed the summit lava dome and were accompanied by pyroclastic flows and surges that devastated an area extending about 8 km around the volcano. The eruptions created a new 1-km-wide, 300-m-deep crater that now contains an acidic crater lake.

Tacaná
México-Guatemala border
Tacaná is a 4060-m-high composite stratovolcano that straddles the México/Guatemala border at the NW end of the Central American volcanic belt. The volcano rises 1800 m above deeply dissected plutonic and metamorphic terrain. Three large calderas breached to the south, and the elongated summit region is dominated by a series of lava domes intruded along a NE-SW trend. Volcanism has migrated to the SW, and a small adventive lava dome is located in the crater of the youngest volcano, San Antonio, on the upper SW flank. Viscous lava flow complexes are found on the north and south flanks, and lobate lahar deposits fill many valleys. Radial drainages on the Guatemalan side are deflected by surrounding mountains into the Pacific coastal plain on the SW side of the volcano. Historical activity at Tacaná has been restricted to mild phreatic eruptions, but more powerful explosive activity, including the production of pyroclastic flows, has occurred as recently as about 1950 years ago.

Guatemala

Tajumulco
Guatemala
Compound volcano
Tajumulco is Guatemala's highest peak and the highest volcano in Central America. Two summits, one with a 50-70 m wide crater, lie along a NW-SE line. A lava flow from the 4220-m-high NW summit traveled down a deep valley on the NW flank. The andesitic-dacitic volcano was constructed over the NW end of a large arcuate SW-facing escarpment of uncertain origin. Tajumulco has had several unconfirmed reports of historical eruptions. Sapper (1917) considered Tajumulco to have erupted during historical time, but without accurate dates. The volcano was reported to eject many rocks, destroying houses on October 24, 1765, but this may have been a rock avalanche. Juarros reported some eruptions before 1808, and there are unlikely reports of eruptions in 1821 (or 1822), 1863, and 1893 (Incer 1988, unpublished manuscript).
Smithsonian Volcano Information | INSIVUMEH, Guatemala

Santa María
Guatemala
Symmetrical, forest-covered Santa María volcano is one of the most prominent of a chain of large stratovolcanoes that rises dramatically above the Pacific coastal plain of Guatemala. The 3772-m-high stratovolcano has a sharp-topped, conical profile that is cut on the SW flank by a large, 1.5-km-wide crater. The oval-shaped crater extends from just below the summit of Volcán Santa María to the lower flank and was formed during a catastrophic eruption in 1902. The renowned plinian eruption of 1902 that devastated much of SW Guatemala followed a long repose period after construction of the large basaltic-andesite stratovolcano. The massive dacitic Santiaguito lava-dome complex has been growing at the base of the 1902 crater since 1922. Compound dome growth at Santiaguito has occurred episodically from four westward-younging vents, the most recent of which is Caliente. Dome growth has been accompanied by almost continuous minor explosions, with periodic lava extrusion, larger explosions, pyroclastic flows, and lahars.
Smithsonian Volcano Information | INSIVUMEH, Guatemala

Almolonga
Volcán de Almolonga is an andesitic stratovolcano with a 3.3-km-wide late-Pleistocene central caldera that is located along the Zunil fault zone. The caldera is surrounded by a ring-dike configuration of dacitic and rhyolitic lava domes. The youngest and only historically active dome complex is Cerro Quemado (whose name means Burned Peak), located immediately south of Guatemala's second largest city, Quezaltenango. About 1200 radiocarbon years ago, part of the andesitic-to-dacitic Cerro Quemado dome collapsed, producing a debris avalanche and an associated lateral explosion that swept across the valley to the west as far as the flanks of Siete Orejas volcano. The latest eruption in 1818 produced a blocky 2.5-km-long lava flow. Hot springs are located on the northern and eastern flanks of Cerro Quemado, and the Zuníl geothermal field, the site of a geothermal exploration project, lies on the SE flank of Cerro Quemado.
Smithsonian Volcano Information | INSIVUMEH, Guatemala

Santo Tomás
Volcán Santo Tomás (also known as Volcán Pecul) is a large eroded stratovolcano located across a valley SE of Santa María volcano. The summit of the volcano is capped by late-Quaternary andesitic tephra. A winding ridge connects Santo Tomás to Volcán de Zunil, 4.5 km to the NE, a 3542-m-high stratovolcano that forms the topographic high point of the Santo Tomás - Zunil complex. Volcán de Zunil is located on the SW rim of the 4-km-wide, 600-m-deep Tzanjuyub caldera, which is breached to the south by the Río Masa. Several dacitic-rhyolitic lava domes are located on the caldera's northern flank and the NW flank of Volcán de Zunil. The youngest dome, Cerro Zunil, was last active about 84,000 years ago (K-Ar dating). No Holocene eruptions are known from Santo Tomás, although it was included in the Catalog of Active Volcanoes of the World (Mooser et al., 1958) based on its geothermal activity. Solfataras and thermal springs are located on the west side of the ridge between Santo Tomás and Zunil.

Atitlán
Twin volcano
Volcán Atitlán is one of several prominent conical stratovolcanoes in the Guatemalan highlands. Along with its twin volcano Tolimán to the north, it forms a dramatic backdrop to Lake Atitlán, one of the scenic highlights of the country. The 3535-m-high summit of Atitlán directly overlies the inferred margin of the Pleistocene Atitlán III caldera and is the highest of three large post-caldera stratovolcanoes constructed near the southern caldera rim. The volcano consequently post-dates the eruption of the voluminous, roughly 85,000-year-old rhyolitic Los Chocoyos tephra associated with formation of the Atitlán III caldera. The historically active andesitic Volcán Atitlán is younger than Tolimán, although their earlier activity overlapped. In contrast to Tolimán, Atitlán displays a thick pyroclastic cover. The northern side of the volcano is wooded to near the summit, whereas the upper 1000 m of the southern slopes are unvegetated. Predominantly explosive eruptions have been recorded from Volcán Atitlán since the 15th century.

Tolimán
Twin volcano
Volcán Tolimán is a large andesitic stratovolcano that rises above the south shore of Lake Atitlán. Tolimán was constructed within the Pleistocene Atitlán III caldera, near its inferred southern margin. A shallow elliptical crater truncates the summit, and a minor subsidiary peak to the SSW also has a shallow crater. In contrast to the tephra-covered surface of its twin volcano to the south, Volcán Atitlán, the surface of Tolimán is draped by prominent thick lava flows. Many of the flows were erupted from vents on the volcano's flanks and form a highly irregular shoreline on the south side of Lake Atitlán. No historical eruptions are known from Tolimán. However, a lava flow that entered Lake Atitlán from the parasitic lava dome of Cerro de Oro on the northern flank was considered by Newhall et al. (1987) to be less than a few thousand years old based on the thickness of sediment accumulated on the sublacustral part of the flow.

Acatenango
Twin volcano
Acatenango, along with its twin volcano to the south, Volcán Fuego, overlooks the historic former capital city of Antigua, Guatemala. Acatenango, which has two principal summits, was constructed during three eruptive periods post-dating the roughly 85,000-year-old Los Chocoyos tephra from Atitlán caldera. An ancestral Acatenango volcano collapsed to the south sometime prior to 43,000 years ago, forming La Democracia debris-avalanche deposit, which covers a wide area of the Pacific coastal plain. Construction of Yepocapa, the northern summit of Acatenango, was completed about 20,000 years ago, after which growth of the southern and highest cone, Pico Central (also known as Pico Mayor), began. The first well-documented eruptions of Acatenango took place from 1924 to 1927, although earlier historical eruptions may have occurred. Francisco Vasquez, writing in 1690, noted that in 1661 a volcano that lay aside of Fuego "opened a smoking mouth and still gives off smoke from another three, but without noise."

Fuego
Volcán Fuego, one of Central America's most active volcanoes, is one of three large stratovolcanoes overlooking Guatemala's former capital, Antigua. The scarp of an older edifice, Meseta, lies between 3763-m-high Fuego and its twin volcano to the north, Acatenango. Construction of Meseta volcano dates back to about 230,000 years and continued until the late Pleistocene or early Holocene. Collapse of Meseta volcano may have produced the massive Escuintla debris-avalanche deposit, which extends about 50 km onto the Pacific coastal plain. Growth of the modern Fuego volcano followed, continuing the southward migration of volcanism that began at Acatenango. In contrast to the mostly andesitic Acatenango volcano, eruptions at Fuego have become more mafic with time, and most historical activity has produced basaltic rocks. Frequent vigorous historical eruptions have been recorded at Fuego since the onset of the Spanish era in 1524, and have produced major ashfalls, along with occasional pyroclastic flows and lava flows.

Agua
The symmetrical, forested Volcán de Agua stratovolcano forms an impressive backdrop to the historic former capital city of Antigua Guatemala, opposite the twin volcanoes of Fuego and Acatenango. The 3760-m-high basaltic-andesite to andesite Agua volcano has an isolated position that makes it a prominent landmark from all directions. A small, 280-m-wide circular crater is breached on the NNE side. Six small pit craters are located on the NW flank, and two small cones lie on the south flank. Agua's symmetrical profile implies a relatively young age, although currently no dated Holocene tephra deposits are known. Agua has had no historical eruptions, but its name (the water volcano) originates from a devastating mudflow on September 11, 1541. The mudflow destroyed the first Guatemalan capital city established by the Spanish Conquistadors, which is now known as Ciudad Vieja. The catastrophe prompted the establishment of a new capital city at nearby Antigua.

Pacaya
Complex volcano
Eruptions from Pacaya, one of Guatemala's most active volcanoes, are frequently visible from Guatemala City, the nation's capital. Pacaya is a complex basaltic volcano constructed just outside the southern topographic rim of the 14 x 16 km Pleistocene Amatitlán caldera. A cluster of dacitic lava domes occupies the southern caldera floor. The post-caldera Pacaya massif includes the Cerro Grande lava dome and a younger volcano to the SW. Collapse of Pacaya volcano about 1100 years ago produced a debris-avalanche deposit that extends 25 km onto the Pacific coastal plain and left an arcuate somma rim inside which the modern Pacaya volcano (MacKenney cone) grew. A subsidiary crater, Cerro Chino, was constructed on the NW somma rim and was last active in the 19th century. During the past several decades, activity at Pacaya has consisted of frequent strombolian eruptions with intermittent lava flow extrusion that has partially filled in the caldera moat and armored the flanks of MacKenney cone, punctuated by occasional larger explosive eruptions that partially destroy the summit of the cone.

Cuilapa-Barbarena
The Cuilapa-Barbarena volcanic field contains approximately 70 Quaternary cinder cones, generally less than 100 m high. Many of the mostly basaltic cones are located along the strike of the major regional Jalpatagua fault, which extends SE from Guatemala City, north of the chain of stratovolcanoes stretching across Guatemala. The cones were erupted from fracture systems related to the intersection of the Jalpatagua fault with the southern and western margins of the Miocene Santa Rosa de Lima caldera and overlie pyroclastic-flow deposits from Amatitlán caldera to the NW. The age of the most recent eruptions is not known, although the youngest cones post-date the last phase of eruptive activity at Tecuamburro volcano and could be of Holocene age (Reynolds, 1987). Williams (1960) considered the most recent eruptions from the Cuilapa-Barbarena volcanic field to have occurred within the last few thousand years.

Tecuamburro
Tuff ring
Tecuamburro is a small, forested stratovolcano or large lava-dome complex of mostly Pleistocene age. It is located about 50 km ESE of Guatemala City, about 20 km south of the main volcanic chain. An ancestral andesitic stratovolcano, Miraflores, was formed about 100,000 years ago. Tecuamburro and other lava domes were constructed during the late Pleistocene or early Holocene within a horseshoe-shaped, east-facing caldera produced by structural failure of the older Miraflores stratovolcano prior to about 38,000 years ago. One of the largest of these domes, Peña Blanca, overtops the NW rim of the collapse scarp. Two nested craters, the larger of which is Chupadero, lie at the NW end of the complex. The smaller crater is a phreatic tuff ring, Laguna Ixpaco, that was formed about 2900 years ago during the latest dated eruption of the Tecuamburro complex. Numerous fumaroles, hot springs, and boiling mud pots are found in the area around the acidic lake. No historical eruptions are known from Tecuamburro.

Jumaytepeque
Jumaytepeque is a small basaltic stratovolcano located NNE of the city of Cuilapa, north of the major NW-SE-trending Jalpatagua fault that cuts diagonally across SE Guatemala. The 1815-m-high volcano was constructed near the SE rim of the large Miocene Santa Rosa de Lima caldera. Jumaytepeque volcano is not overlain by a ca. 23,000-year-old tephra unit from nearby Ayarza caldera, and its erosionally unmodified form suggests that Holocene activity is possible (Reynolds 2007, pers. comm.). Two older cinder cones to the north are covered with Ayarza tephra.

Moyuta
Moyuta is the easternmost of a chain of large stratovolcanoes extending along the volcanic front of Guatemala. Like Tecuamburro volcano, Moyuta is offset about 20 km south of the main volcanic chain and lies south of the Jalpatagua Fault, overlying the southern boundary of the Jalpatagua Graben. The 1662-m-high volcano is capped by a cluster of at least three forested, steep-sided, coalescing andesitic lava domes that from some distant perspectives give the summit a flat-topped appearance. Numerous cinder cones in various stages of erosion are located on the flanks of the complex. The age of the latest eruption of Moyuta volcano is not known, although the summit domes were considered to have been emplaced in relatively recent times (Williams et al., 1964). Small fumaroles are found on the northern and southern flanks of the volcano, and hot springs are located near Azulco at the NE base and along rivers on the SE side of Moyuta.

Flores
Volcán de Flores is one of the largest of a cluster of small stratovolcanoes located in SE Guatemala behind the volcanic front. Volcán de Flores, also known as Volcán Amayo, lies about 10 km west of the city of Jutiapa, at the SW end of the SE Guatemala volcanic platform. The 1600-m-high summit rises up to 600 m above a basement of Cretaceous and Tertiary sedimentary rocks and contains a shallow crater breached on its eastern side. Satellitic cones occur at the southern and eastern base of the dominantly basaltic Flores volcano. Youthful lava flows occur at the NE base of the volcano, near El Aguacite.

Tahual
Cinder cone
Deeply dissected Volcán Tahual rises about 700 m above plains south of the town of Monjas. The summit of the 1716-m-high forested stratovolcano is cut by a broad erosional crater that extends to the base of the volcano and is narrowly breached to the NE. A Holocene pyroclastic cone near the NE base of Volcán Tahual fed a short basaltic lava flow (Williams et al., 1964). The scenic lake-filled Laguna de Hoyo lies north of the volcano. This steep-walled crater and the NE-flank cinder cone lie along faults bordering a graben that extends across the eastern base of the volcano to neighboring Retana caldera on the SE.

Cerro Santiago
A cluster of cinder cones and low shield volcanoes surrounds the city of Jutiapa in SE Guatemala. The most prominent feature is Cerro Santiago, one of two coalescing cinder cones capping a low shield volcano SE of Jutiapa. Youthful flows from the twin Los Cerritos cones NE of Jutiapa cross the Interamerican highway. Volcán Culma forms a steep-sided basaltic lava mound immediately east of the city. To the west lies Cerro Gordo (referred to by Williams et al., 1964 as Volcano Amayo), a craterless cinder cone surrounded by basaltic lava flows. It is one of several cinder cones to have produced lava flows that blanket the landscape between Jutiapa and Tertiary volcanic hills to the south.

Suchitán
Volcán Suchitán, NE of the city of Jutiapa, is one of the largest volcanoes in SE Guatemala. The 2042-m-high summit of the andesitic-to-basaltic stratovolcano is elongated in a N-S direction. Several large canyons cut the slopes of the dominantly andesitic edifice. A large parasitic cone, Cerro Mataltepe, is located on the upper northern flank, and two smaller cones are located on the lower northern flank. Two basaltic lava flows of Holocene age are located on the northern and NW flanks (Williams et al., 1964), and many flank vents are basaltic. Suchitán was constructed immediately to the east of the 5-km-wide basaltic-to-dacitic Retana caldera, formed in part in association with the eruption of a dacitic pumice deposit. Steep walls 60-250-m high rise above the flat caldera floor. One of the latest basaltic lava flows from Suchitán flowed through a low notch in the eastern caldera rim. Several lava cones and a maar are located along a N-S line north of Retana caldera. A reported eruption of Suchitán in 1469 is considered to have actually been from Atitlán volcano in the Guatemalan highlands.

Chingo
Volcán Chingo is a symmetrical stratovolcano that straddles the Guatemala/El Salvador border. The 1775-m-high conical volcano rises 900 m above its surroundings and is the most prominent regional landmark. A shallow, oval-shaped summit crater is breached on the western side. No historical eruptions are known from the Volcán Chingo volcanic field. Other small stratovolcanoes and cinder cones are located on both sides of the volcano along a major N-S-trending fault. Other youthful cones, such as Cerro de Olla, lie across the Salvadorian border to the south. To the north in Guatemala, Volcán las Viboras, a cinder cone that caps a basaltic shield volcano, is the most prominent of several fault-controlled cones near Laguna Atescatempo. Flank fissures have fed many youthful lava flows, particularly on the western flank of Chingo and the northern flank of Volcán las Viboras.

Ixtepeque
Ixtepeque volcano, which takes its name from the Aztec word for obsidian, is perhaps the largest obsidian field in North America. A 4 x 5 km wide rhyolitic obsidian lava field was erupted within the Ipala graben from a craterless vent along a NE-trending fissure that passes through adjacent rhyolitic lava domes and basaltic cinder cones. Obsidian from Ixtepeque has shown up at archaeological sites across Central America. Flat-lying pumice beds produced by explosive eruptions preceding lava effusion are found locally around the volcano. Other obsidian flows originated from lava domes NE of Ixtepeque. These rhyolitic vents are interspersed with basaltic cinder cones and lava flows. Laguna de Obrajuelo is a complex cone cut by a large crater more than a km in diameter. Initial basaltic eruptions were followed by the extrusion of obsidian flows and the eruption of rhyolitic pumice that were considered by Williams et al. (1964) to be only a few thousand years old.

Ipala
Ipala is a small but prominent stratovolcano that extends nearly across the full width of the Ipala graben and rises 750 m above the graben floor. The 1650-m-high summit of Volcán Ipala is truncated by a 1-km-wide crater whose steep, 150-m-high walls tower above a lake. A prominent parasitic cone, Monte Rico, is located on the southern flank; it and other cones on the northern flank lie along a N-S-trending fracture that continues well beyond the southern flank of the volcano. The eastern flank of Ipala is cut by a 17-km long, NNE-SSW fissure that produced a conspicuous line of Holocene cinder cones that fed basaltic lava flows covering about 20 sq km. Diaz reported that in 1865 Ipala ejected ash from January 24 to June. He listed no source and the report seems improbable (Incer 1988, unpublished manuscript).

Chiquimula Volcanic Field
Lava cones
The Chiquimula volcanic field occupies a fault-bounded basin underlain by Cretaceous plutonic rocks in the Chiquimula Valley of SE Guatemala. Initial eruptions during the Pleistocene produced mesa-forming basaltic lava flows along the N-S-trending fault forming the eastern edge of the Ipala graben. These were followed by the eruption of widespread lava flows NW of Chiquimula town that covered about 12 sq km. The most recent eruptions produced basaltic cinder cones and lava flows near the northern edge of Chiquimula town. The cinder cones were constructed along a N-S-trending fracture, with Cerro Grande at the northern end being the largest and Cerro Chiquito at the southern end being the youngest. The lava flows from Cerro Chiquito are so fresh and sparsely vegetated they were considered by Williams et al. (1964) to possibly be less than 1000 years old.

Quezaltepeque
A series of youthful lava flows was erupted from vents cutting through Tertiary pyroclastic rocks WNW of Ipala volcano about 5 km south of the town of Quezaltepeque. These basaltic flows issued passively from vents along a N-S-trending fault without accompanying explosive activity. The vents are capped by low mounds of lava. The flows were considered to be of Holocene age by Williams et al. (1964).

El Salvador & Honduras

San Diego
El Salvador
An extensive volcanic field of fresh-looking basaltic cinder cones and barren lava flows near Lake Güija, which straddles the border between El Salvador and Guatemala, is named after its largest feature, 781-m-high Volcán de San Diego. A large basaltic lava flow from the San Diego cinder cone dammed the drainage and was responsible for the formation of Lake Güija. Volcanism is concentrated in two areas near Lake Güija--an area of volcanic cones including San Diego east of the lake, and an area of small cones north of the lake near the Guatemalan border, north of the Río Ostua. None of the eruptions in the San Diego volcanic field have been dated, but Williams and McBirney (1955) estimated that the latest eruption occurred within the past few thousand years. Quaternary volcanic rocks are also located across Lake Güija in Guatemala.
Smithsonian Volcano Information | Servicio Nacional de Estudios Territoriales

Cerro Singüil
El Salvador
Explosion craters
The most prominent feature of a volcanic field in the interior valley of El Salvador near the Guatemalan border SE of Volcán Chingo is Cerro Singüil. This 957-m-high scoria cone, also known as El Cerron, has a well-preserved summit crater and is part of a group of cinder cones and explosion craters mapped as Holocene in age by Weber and Wiesemann (1978). A young basaltic lava flow extends to the NNE down the valley of the Quebada La Presa, the headwaters of the Río Guajoyo. The volcanic field includes a line of three NNE-trending explosion craters north of the city of Chalchuapa, the highest of which is 1035-m-high Cerro Tablas.
Smithsonian Volcano Information | Servicio Nacional de Estudios Territoriales

Apaneca Range
El Salvador
The Apaneca Range (also known as the Cuyanausul Range) consists of an elongated group of roughly E-W-trending basaltic-to-andesitic Pleistocene and Holocene stratovolcanoes in western El Salvador between the Santa Ana complex and the Guatemala border. The 5 x 3.5 km wide Pleistocene dacitic-rhyolitic Concepción de Ataco caldera lies at the western end of the complex, along with post-caldera late-Pleistocene to Holocene andesitic-dacitic lava domes. The post-caldera cones of Cerro el Aguila (at 2036 m the highest peak of the complex) and Cerro los Naranjos volcano at the eastern end of the chain were mapped as Holocene by Weber and Weisemann (1978). Young craters on basaltic Laguna Verde stratovolcano may also have been active during the Holocene. Numerous fumarole fields are located on the northern flank of the range, and the Ahuachapán geothermal field has been producing since 1975. Several small hydrothermal explosions have occurred in historical time, including one in October 1990 at the Agua Shuca thermal area in which 26 persons were killed.
Smithsonian Volcano Information | Servicio Nacional de Estudios Territoriales

Santa Ana
Santa Ana, El Salvador's highest volcano, is a massive, 2381-m-high andesitic-to-basaltic stratovolcano that rises immediately west of Coatepeque caldera. Collapse of Santa Ana (also known as Ilamatepec) during the late Pleistocene produced a voluminous debris avalanche that swept into the Pacific Ocean, forming the Acajutla Peninsula. Reconstruction of the volcano subsequently filled most of the collapse scarp. The broad summit of the volcano is cut by several crescentic craters, and a series of parasitic vents and cones have formed along a 20-km-long fissure system that extends from near the town of Chalchuapa NNW of the volcano to the San Marcelino and Cerro la Olla cinder cones on the SE flank. Historical activity, largely consisting of small-to-moderate explosive eruptions from both summit and flank vents, has been documented since the 16th century. The San Marcelino cinder cone on the SE flank produced a lava flow in 1722 that traveled 13 km to the east.

Izalco
Volcán de Izalco, El Salvador's youngest volcano, was born in in 1770 AD on the southern flank of Santa Ana volcano. Frequent strombolian eruptions from Izalco provided a night-time beacon for ships, causing the volcano to be known as El Faro, the "Lighthouse of the Pacific." During the two centuries prior to the cessation of activity in 1966, Izalco built a steep-sided, 650-m-high stratovolcano truncated by a 250-m-wide summit crater. Izalco has been one of the most frequently active volcanoes in North America, and its sparsely vegetated slopes contrast dramatically with neighboring forested volcanoes. Izalco's dominantly basaltic-andesite pyroclasts and lava flows are geochemically distinct from those of both Santa Ana and its fissure-controlled flank vents. Lava flows from Izalco were mostly erupted from flank vents and were deflected southward by the slopes of Santa Ana volcano, traveling as far as about 7 km from the summit of Izalco.

Coatepeque Caldera
The 7 x 10 km Coatepeque caldera, its eastern side filled by a caldera lake, was formed by collapse of a group of stratovolcanoes immediately east of Santa Ana volcano. The height of the caldera rim increases to 800 m on the west, where it partially truncates Santa Ana volcano. The caldera was formed during a series of major rhyolitic explosive eruptions between about 72,000 and 57,000 years ago. Post-caldera eruptions included the formation of basaltic cinder cones and lava flows near the western margin of the caldera and the extrusion of a half dozen rhyodacitic lava domes along a NE-SW line near the caldera lake margins. The highest of the domes forms the wooded island of Isla de Cabra, or Cerro Grande. The age of the domes is not known precisely, but the youngest dome, Cerro Pacho, was estimated to have formed less than 10,000 years ago. Hot springs occur near the lake margins, but no verified historical eruptions have occurred from Coatepeque.

San Salvador
The massive compound San Salvador volcano dominates the landscape west of El Salvador's capital city of San Salvador. The dominantly andesitic Boquerón stratovolcano has grown within a 6-km-wide caldera, whose rim is partially exposed at Picacho and Jabalí peaks, that formed by collapse of an older San Salvador volcano about 40,000 years ago. The summit of Boquerón is truncated by a steep-walled crater 1.5 km wide and about 500 m deep that formed during a major eruption about 800 years ago. It contained a crater lake prior to an eruption during 1917 that formed a small cinder cone on the crater floor; a major north-flank lava flow also erupted in this year. Three fracture zones that extend beyond the base of San Salvador volcano have been the locus for numerous flank eruptions, including two that formed maars on the WNW and SE sides. Most of the four historical eruptions recorded since the 16th century have originated from flank vents, including two in the 17th century from the NW-flank cone of El Playón, during which explosions and a lava flow damaged inhabited areas.

Cerro Cinotepeque
Cerro Cinotepeque is the largest and most prominent of a group of four pyroclastic cones of Holocene age mapped by Weber and Weismann (1978) in low-lying areas on either side of the Río Lempa, about 40 km north of San Salvador. Cerro Cinotepeque (also spelled Cinotepec) lies south of the river; two other cones, Cerro Santiago and Cerro Mosquito, lie immediately north of the river. A fourth cone is located along the Río Gualchayo about 10 km farther north. A large group of small Pleistocene stratovolcanoes and pyroclastic cones constructed along NW-SE-trending faults is located west and south of Cerro Cinotepeque and west of Guazapa volcano.

Guazapa
Guazapa is a massive, eroded Pleistocene stratovolcano that rises 1000 m above the surrounding countryside NE of the capital city of San Salvador. The 1438-m-high basaltic volcano has no trace of its original summit crater, and deep canyons cut its flanks. Several young Holocene pyroclastic cones and lava flows of similar composition are found at the base of the volcano (Williams and Meyer-Abich, 1955). The Macanze scoria cone at the SE base of the volcano was considered to have probably been active only a few thousand years ago, however Weber and Wiesemann (1978) did not map Holocene vents in this area.

Ilopango
The scenic 8 x 11 km Ilopango caldera, filled by one of El Salvador's largest lakes, has a scalloped 150-500 m high rim. The caldera, which lies immediately east of the capital city of San Salvador, is strongly controlled by regional faults of the central Salvador graben. Four major dacitic-rhyolitic explosive eruptions during the late Pleistocene and Holocene produced extensive pyroclastic-flow and pyroclastic-fall deposits that blanket much of El Salvador. The latest collapse of Ilopango caldera resulted from the massive 5th century AD Terra Blanca Joven (TBJ) eruption, which produced widespread pyroclastic flows and devastated early Mayan cities. Post-caldera eruptions formed a series of glassy dacitic and andesitic lava domes within the lake and near its shore. The Islas Quemadas, a group of low islets in the center of the lake that mark the summit of a largely submerged lava dome, were formed in 1879-80 during the only historical eruption of Ilopango.

San Vicente
The twin peaks of San Vicente volcano, also known as Chichontepec, rise dramatically to the SE of Lake Ilopango. The modern andesitic stratovolcano was constructed within the Pleistocene La Carbonera caldera, whose rim is visible only on its SW side. San Vicente volcano, the second highest in El Salvador, grew within the caldera to form a paired volcano with summit craters oriented along a WSW-ENE line. The northern and southern flanks are covered by lava flows from the central vent, but lava flows on the eastern side originated from a vent on the upper flank. Volcanism has continued into the Holocene, but the latest lava flows are covered by deposits from the major ca. 260 AD eruption from neighboring Ilopango volcano. Reports of historical eruptions in 1643 and 1835 are false (Catalog of Active Volcanoes of the World; Sapper, 1917), but numerous hot springs and fumaroles are found on the northern and western flanks of the volcano.

Apastepeque Field
The Apastepeque volcanic field north of the city of San Vicente consists of a dense cluster of about two dozen chemically diverse Holocene volcanic vents, including lava domes, cinder cones, and maars. Andesitic-to-dacitic lava domes were emplaced in some vents following dacitic pumice eruptions. After the end of these more siliceous eruptions, a series of basaltic cinder cones was formed. Some of the basaltic eruptions concluded with the formation of steep-walled maars up to 100 m deep, some now occupied by lakes, such as Laguna de Apastepeque and Laguna Chalchuapán.

Taburete
Taburete volcano rises above the Pacific coastal plain east of the Río Lempa at the SW end of a cluster of volcanoes between San Vincente and San Miguel volcanoes. Basaltic to basaltic-andesite Volcán Taburete is elongated in a NW-SE direction and overlaps with Tecapa volcano to the NE. The 1172-m-high summit of Taburete forms a prominent peak that rises about 170 m above the southern crater rim. A well-preserved, 150-300 m deep summit crater has a low point on its eastern rim. A fairly recent lava flow descends the southern flank of the volcano (Williams and McBirney, 1955). Loma Pacha cone on the lower SE flank fed a thick lava flow that traveled 1 km to the SE. The age of the most recent eruption of Taburete is not precisely known, and Weber and Wiesemann (1978) did not map Holocene deposits from Taburete.

Tecapa
Tecapa is a complex basaltic-to-andesitic stratovolcano at the NW end of a cluster of volcanoes east of the Río Lempa between San Vicente and San Miguel volcanoes. The Berlín caldera, whose rim is visible on the west side of the complex, was formed during the eruption of the Blanca-Rosa dacitic pumice in the late Pleistocene. Following caldera formation the cones of Cerro Las Palmas, Cerro Pelón, Tecapa-Laguna de Alegria, and Cerro Alegria were constructed along a WSW-ENE line. The crater of Tecapa-Laguna de Alegria contains a deep notch on the eastern rim and is filled by Laguna de Alegria crater lake. The Tecapa volcanic complex currently displays fumarolic activity, and a producing geothermal plant is located at the Berlín geothermal field.

Usulután
Usulután volcano anchors the SE end of a cluster of basaltic to basaltic-andesite stratovolcanoes between San Vicente and San Miguel volcanoes. The flanks of the forested Usulután volcano are dissected, but youthful lava flows are present on its southern flanks. The younger summit rocks of 1449-m-high Usulután and Cerro Nanzal pyroclastic cone on the lower SE flank were mapped as Holocene (Weber and Wiesemann, 1978). A broad 1.3-km-wide crater is breached to the east from the summit of Usulután to its lower flank.

El Tigre
Cerro el Tigre is the highest, NE-most, and oldest of the cluster of coalescing basaltic to basaltic-andesite Quaternary volcanoes between the Río Lempa and San Miguel volcano. The summit crater of El Tigre has been destroyed by erosion, and the flanks of the volcano are deeply dissected. Two large NNW-trending valleys, parallel to other regional fissures, cross the volcano, which lies about 7 km SE of Tecapa volcano and a similar distance NE of Usulután volcano. Although El Tigre itself is Pleistocene in age, two young cones on its flanks were mapped as Holocene by Weber and Wiesemann (1978). Cerro Oromontique and Cerro la Manita were erupted on the western and southern flanks of El Tigre, respectively, along a NW-SE-trending fissure extending towards Tecapa volcano.

Chinameca
Cinder cone
The small stratovolcano of Chinameca (also known as El Pacayal) is dwarfed by its towering neighbor San Miguel, which lies across a low saddle to the SE. A 2-km-wide, steep-sided caldera, Laguna Seca el Pacayal, truncates the 1300-m-high summit of Chinameca volcano, whose flanks are draped with coffee plantations. The Holocene cone of Cerro el Limbo on the western flank rises to 1380 m, above the level of the caldera rim, and a Holocene lava flow extends from a NNW-flank vent into the lowlands to the north beyond the town of Chinameca (Weber and Weisemann, 1978). A group of fumarole fields is located on the north flank of the volcano surrounds the city of Chinameca, and the volcano has been the site of a geothermal exploration program.

San Miguel
The symmetrical cone of San Miguel volcano, one of the most active in El Salvador, rises from near sea level to form one of the country's most prominent landmarks. The unvegetated summit of the 2130-m-high volcano rises above slopes draped with coffee plantations. A broad, deep crater complex that has been frequently modified by historical eruptions (recorded since the early 16th century) caps the truncated summit of the towering volcano, which is also known locally as Chaparrastique. Radial fissures on the flanks of the basaltic-andesitic volcano have fed a series of historical lava flows, including several erupted during the 17th-19th centuries that reached beyond the base of the volcano on the north, NE, and SE sides. The SE-flank lava flows are the largest and form broad, sparsely vegetated lava fields crossed by highways and a railroad skirting the base of the volcano. The location of flank vents has migrated higher on the edifice during historical time, and the most recent activity has consisted of minor ash eruptions from the summit crater.

Laguna Aramuaca
Maar
A solitary, 1-km-wide, lake-filled maar, Laguna Aramuaca, occupies a low-lying area about 10 km SE of the city of San Miguel. The Pan-American highway swings around the south side of the maar immediately north of the Río Grande de San Miguel. Laguna Aramuaca was mapped as Holocene by Weber and Wiesemann (1978), but has not been studied in detail. The low rim of the maar rises about 50-100 m above the countryside and reaches only 181 m above sea level. Spectacular pyroclastic-surge deposits are exposed by quarries near the rim of the maar.

Conchagüita
Conchagüita volcano occupies a small, 4-km-wide island in the Gulf of Fonseca across a narrow strait from Conchagua volcano. Late-stage eruptions formed a small, sharp-topped cone with a 100-m-wide summit crater at the southern end of the low 505-m-high island, and a youthful peninsula also extends from the island's eastern side. A crescent-shaped crater open to the west is located at the northern end of the island. Minor ash emissions in 1892 marked the only historical eruption from Conchagüita, the easternmost Holocene volcano in El Salvador.

Isla el Tigre
Honduras
Isla El Tigre is a small, 5-km-wide island located across a narrow 2-km-wide strait south of Isla Zacate Grande in the Gulf of Fonseca. The conical, 783-m-high basaltic stratovolcano is the southernmost volcano of Honduras. El Tigre is less dissected than neighboring Zacate Grande volcano on the mainland to the north and is of probable Holocene age (Carr 1992, pers. comm.). A single satellitic cone, El Vigía, overlooks the village of Amapala on the NW flank.

Isla Zacate Grande
Honduras
Zacate Grande volcano forms a low 7 x 10 km wide island across a narrow strait from the end of a peninsula surrounded on three sides by the Gulf of Fonseca and Chismuyo bay. At least seven satellitic cones, some of which form small islands offshore, are located from the NE to SE base of the broad 640-m-high basaltic stratovolcano. Some of these, including the symmetrical cone of Isla Gueguensi in the tidal flats about 3 km east of the base of Zacate Grande, are of probable Holocene age (Carr 1992, pers. comm.). In contrast to neighboring Isla El Tigre volcano to the south, Zacate Grande itself is extensively eroded, and deep valleys extend from the summit ridges to the base of the volcano.

Lake Yojoa
Honduras
The Lake Yojoa volcanic field consists a group of Pleistocene-to-Holocene scoria cones and collapse pits at the northern end of the scenic north-central Honduras lake (Williams and McBirney, 1969). The volcanic field has produced rocks ranging from tholeiitic basalts to trachybasalts, trachyandesites, and trachytes. The principal NE-trending chain of cones cuts through Cerro Babilonia, the 1090 m high point of the volcanic field, along the same fault pattern that bounds the limestone mountains bordering arcuate Lake Yojoa. Most of the pyroclastic cones, consisting of basaltic scoria and agglutinate, are 100-200 m in height and several contain well-preserved craters. Lava flows radiate in all directions from the cones. The longest flow traveled northward to the village of Río Lindo, where a waterfall cascades down the terminus of the flow. A few Quaternary lava flows occur in the Sulu graben along the Carretara del Norte north of Lake Yojoa.

Utila Island
The island of Utila in the Carribean Sea off the northern coast of Honduras is the easternmost and lowest of the Bay Islands at the southern edge of the submarine Bartlett Trough. Utila is capped by a thin veneer of Holocene basaltic rocks at its eastern end (McBirney and Bass, 1969). Basaltic lavas and tuffs were erupted onto a coral-capped erosional surface. Stuert Hill (also spelled Stuart Hill) is a pyroclastic cone that was constructed at the center of the volcanic terrain, and Pumpkin Hill is a small littoral cone located along the NE coast of the island. The high point of the island is Pumpkin Hill, which rises only 74 m above sea level.

Nicaragua

Cosigüina
Nicaragua
Cosigüina is a low basaltic-to-andesitic composite volcano that is isolated from other eruptive centers in the Nicaraguan volcanic chain. The 872-m-high stratovolcano forms a large peninsula extending into the Gulf of Fonseca at the western tip of the country. Cosigüina (also spelled Cosegüina) has a pronounced somma rim on the northern side; a young summit cone of Cosigüina rises 300 m above the northern somma rim and buries the rim on other sides. The younger cone is truncated by a large elliptical prehistorical summit caldera, 2 x 2.4 km in diameter and 500 m deep, with a lake at its bottom. Lava flows predominate in the caldera walls, although lahar and pyroclastic-flow deposits surround the volcano. In 1835 Cosigüina was the source of a brief, but powerful explosive eruption that was Nicaragua's largest during historical time. Ash fell as far away as México, Costa Rica, and Jamaica, and pyroclastic flows reached the Gulf of Fonseca.
Smithsonian Volcano Information | Instituto Nicaragüense de Estudios Territoriales

San Cristóbal
Nicaragua
The San Cristóbal volcanic complex, consisting of five principal volcanic edifices, forms the NW end of the Marrabios Range. The symmetrical 1745-m-high youngest cone, named San Cristóbal (also known as El Viejo), is Nicaragua's highest volcano and is capped by a 500 x 600 m wide crater. El Chonco, with several flank lava domes, is located 4 km to the west of San Cristóbal; it and the eroded Moyotepe volcano, 4 km to the NE of San Cristóbal, are of Pleistocene age. Volcán Casita, containing an elongated summit crater, lies immediately east of San Cristóbal and was the site of a catastrophic landslide and lahar in 1998. The Plio-Pleistocene La Pelona caldera is located at the eastern end of the San Cristóbal complex. Historical eruptions from San Cristóbal, consisting of small-to-moderate explosive activity, have been reported since the 16th century. Some other 16th-century eruptions attributed to Casita volcano are uncertain and may pertain to other Marrabios Range volcanoes.
Smithsonian Volcano Information | Instituto Nicaragüense de Estudios Territoriales

Telica
Telica, one of Nicaragua's most active volcanoes, has erupted frequently since the beginning of the Spanish era. The Telica volcano group consists of several interlocking cones and vents with a general NW alignment. Sixteenth-century eruptions were reported at symmetrical Santa Clara volcano at the SW end of the Telica group. However, its eroded and breached crater has been covered by forests throughout historical time, and these eruptions may have originated from Telica, whose upper slopes in contrast are unvegetated. The steep-sided cone of 1061-m-high Telica is truncated by a 700-m-wide double crater; the southern crater, the source of recent eruptions, is 120 m deep. El Liston, immediately SE of Telica, has several nested craters. The fumaroles and boiling mudpots of Hervideros de San Jacinto, SE of Telica, form a prominent geothermal area frequented by tourists, and geothermal exploration has occurred nearby.
Smithsonian Volcano Information | Instituto Nicaragüense de Estudios Territoriales

Rota
The deeply eroded, forested Rota stratovolcano of Holocene age occupies the area between Cerro Negro volcano and the Telica volcanic complex in the central Marrabios Range. The 832-m-high volcano, also known as Orota, is truncated by a 1-km-wide circular crater whose rim is lowest on the southern side. The latest eruption from Rota produced thick andesitic lava flows from a NE-trending fissure NW of the summit. No historical eruptions are known from Volcán Rota, and Williams and McBirney (1965) considered the volcano to have been quiescent for many centuries. Seismic swarms occurred in 1986, 1989, and 1992. Two small NNW-SSE-trending lava domes, El Bosque (also known as Lomas San Ignacio del Bosque or Cerro Ojochal) are located on the plain 2 km north of the flank of Rota. They were constructed along the same trend as other eruptive fissures that extend transverse to the Marrabios Range volcanoes. An extensive lava field in this area was erupted from numerous small cones and maars.

Cerro Negro
Central America's youngest volcano, Cerro Negro, was born in April 1850 and has since been one of the most active volcanoes in Nicaragua. Cerro Negro is the largest, southernmost, and most recent of a group of four youthful cinder cones constructed along a NNW-SSE-trending line in the central Marrabios Range 5 km NW of Las Pilas volcano. Strombolian-to-subplinian eruptions at Cerro Negro at intervals of a few years to several decades have constructed a roughly 250-m-high basaltic cone and an associated lava field that is constrained by topography to extend primarily to the NE and SW. Cone and crater morphology at Cerro Negro have varied significantly during its eruptive history. Although Cerro Negro lies in a relatively unpopulated area, its occasional heavy ashfalls have caused damage to crops and buildings in populated regions of the Nicaraguan depression.

Las Pilas
Complex volcano
Las Pilas volcanic complex, overlooking Cerro Negro volcano to the NW, includes a diverse cluster of cones around the central vent, Las Pilas. A N-S-trending fracture system cutting across 1088-m-high Las Pilas (El Hoyo) is marked by numerous well-preserved flank vents, including maars, that are part of a 30-km-long volcanic massif. The Cerro Negro chain of cinder cones is listed separately in this compilation because of its extensive historical eruptions. The lake-filled Asososca maar is located adjacent to the conical 818-m-high Cerro Asososca cone on the southern side of the fissure system, south of the axis of the Marrabios Range. Two small maars west of Lake Managua are located at the southern end of the fissure. Aside from a possible eruption in the 16th century, the only historical eruptions of Las Pilas took place in the 1950s from a fissure that cuts the eastern side of the 700-m-wide summit crater and extends down the north flank.

Momotombo
Momotombo is a young, 1297-m-high stratovolcano that rises prominently above the NW shore of Lake Managua, forming one of Nicaragua's most familiar landmarks. Momotombo began growing about 4500 years ago at the SE end of the Marrabios Range and consists of a somma from an older edifice that is surmounted by a symmetrical younger cone with a 150 x 250 m wide summit crater. Young lava flows from Momotombo have flowed down the NW flank into the 4-km-wide Monte Galán caldera. The youthful cone of Momotombito forms a 391-m-high island offshore in Lake Managua. Momotombo has a long record of strombolian eruptions, punctuated by occasional larger explosive activity. The latest eruption, in 1905, produced a lava flow that traveled from the summit to the lower NE base. A small black plume was seen above the crater after an April 10, 1996 earthquake, but later observations noted no significant changes in the crater. A major geothermal field is located on the southern flank of the volcano.

Apoyeque
Pyroclastic shield
Maar
The Apoyeque volcanic complex occupies the broad Chiltepe Peninsula, which extends into south-central Lake Managua. The peninsula is part of the Chiltepe pyroclastic shield volcano, one of three large ignimbrite shields on the Nicaraguan volcanic front. A 2.8-km wide, 400-m-deep, lake-filled caldera whose floor lies near sea level truncates the low Apoyeque volcano, which rises only about 500 m above the lake shore. The caldera was the source of a thick mantle of dacitic pumice that blankets the surrounding area. The 2.5 x 3 km wide lake-filled Xiloá (Jiloá) maar, is located immediately SE of Apoyeque. The Talpetatl lava dome was constructed between Laguna Xiloá and Lake Managua. Pumiceous pyroclastic flows from Laguna Xiloá were erupted about 6100 years ago and overlie deposits of comparable age from the Masaya plinian eruption.

Nejapa-Miraflores
Fissure vents
The N-S-trending Nejapa-Miraflores alignment, located near the western margin of the Nicaraguan graben, cuts through the western part of Nicaragua's capital city, Managua. This alignment, which has erupted tholeiitic basaltic rocks similar to those from mid-ocean ridges, marks the right-lateral offset of the Nicaraguan volcanic chain. A series of pit craters and fissure vents extends into Lake Managua and is continuous with the volcanic vents on the Chiltepe peninsula. An area of maars and tuff cones perpendicular to the N-S trend of the lineament forms the scalloped shoreline of Lake Managua. Laguna Tiscapa crater is located several kilometers to the east near the central part of the city of Managua. The elongated Nejapa and Ticoma pit craters are surrounded by small basaltic cinder cones and tuff cones. The Nejapa-Miraflores alignment (also known as Nejapa-Ticoma) has been the site of about 40 eruptions during the past 30,000 years, the most recent of which (from Cerro Motastepe) occurred less than 2500 years ago.

Masaya
Masaya is one of Nicaragua's most unusual and most active volcanoes. Masaya lies within the massive Pleistocene Las Sierras pyroclastic shield volcano and is a broad, 6 x 11 km basaltic caldera with steep-sided walls up to 300 m high. The caldera is filled on its NW end by more than a dozen vents erupted along a circular, 4-km-diameter fracture system. The twin volcanoes of Nindirí and Masaya, the source of historical eruptions, were constructed at the southern end of the fracture system and contain multiple summit craters, including the currently active Santiago crater. A major basaltic plinian tephra was erupted from Masaya about 6500 years ago. Historical lava flows cover much of the caldera floor and have confined a lake to the far eastern end of the caldera. A lava flow from the 1670 eruption overtopped the north caldera rim. Masaya has been frequently active since the time of the Spanish Conquistadors, when an active lava lake prompted attempts to extract the volcano's molten "gold." Periods of long-term vigorous gas emission at roughly quarter-century intervals cause health hazards and crop damage.

Granada
Fissure vents
A semi-arcuate, N-S-trending fissure located between the city of Granada and the eastern rim of Apoyo caldera was the source of the Granada alignment of small cinder cones and craters. The lineament (also known as the La Joya alignment after La Joya explosions craters SW of Granada) cuts across the flanks of Apoyo caldera only 2 km from its rim. However, the Granada alignment is structurally distinct from the caldera and is analogous to the Nejapa-Miraflores alignment north of Masaya volcano. The lineament extends from north of Granada to the northern flanks of Mombacho volcano and is characterized by the eruption of basaltic lavas and tephras compositionally similar to mid-ocean ridge basalts. A series of interconnecting collapse-explosion pits similar to those at Nejapa-Miraflores lies immediately east of the Granada cinder cone alignment. The Granada lineament originated about 12,000 years ago, and the latest eruptions may have occurred as recently as about 2000 years ago.

Mombacho
Mombacho is an andesitic and basaltic stratovolcano on the shores of Lake Nicaragua south of the city of Granada that has undergone edifice collapse on several occasions. Two large horseshoe-shaped craters formed by edifice failure cut the summit on the NE and southern flanks. The NE-flank scarp was the source of a large debris avalanche that produced an arcuate peninsula and a cluster of small islands (Las Isletas) in Lake Nicaragua. Two small, well-preserved cinder cones are located on the volcano's lower northern flank. The only reported historical activity was in 1570, when a debris avalanche destroyed a village on the south side of the volcano. Although there were contemporary reports of an explosion, there is no direct evidence that the avalanche was accompanied by an eruption. Fumarolic fields and hot springs are found within the two collapse scarps and on the upper northern flank.

Zapatera
Zapatera is a small low shield volcano that forms a 7 x 10 km wide island on the western side of Lake Nicaragua just offshore from Mombacho volcano. The island contains some of the most significant archaeological sites in Nicaragua. The small, roughly circular 2-km-wide El Llano caldera is located near the center of the island, which is cut by a series of NE-trending faults that continue into Lake Nicaragua. The conical 305-m-high Cerro El Llano lava dome occupies the center of the caldera, and other lava domes are found on the southern and NE flanks. Numerous low-rimmed tuff rings and maars, of which Laguna de Zapatera on the NW flank is the best-preserved, are found on the northern and western sides of the densely forested 629-m-high island and across a narrow strait on the adjacent mainland.

Concepción
Volcán Concepción is one of Nicaragua's highest and most active volcanoes. The symmetrical basaltic-to-dacitic stratovolcano forms the NW half of the dumbbell-shaped island of Ometepe in Lake Nicaragua and is connected to neighboring Madera volcano by a narrow isthmus. A steep-walled summit crater is 250 m deep and has a higher western rim. N-S-trending fractures on the flanks of the volcano have produced chains of spatter cones, cinder cones, lava domes, and maars located on the NW, NE, SE, and southern sides extending in some cases down to Lake Nicaragua. Concepción was constructed above a basement of lake sediments, and the modern cone grew above a largely buried caldera, a small remnant of which forms a break in slope about halfway up the north flank. Frequent explosive eruptions during the past half century have increased the height of the summit significantly above that shown on current topographic maps and have kept the upper part of the volcano unvegetated.

Maderas
Volcán Maderas is a roughly conical, 1394-m-high stratovolcano that forms the SE end of the dumbbell-shaped Ometepe island in Lake Nicaragua. The basaltic-to-dacitic volcano is cut by numerous faults and grabens, the largest of which is a NW-SE-oriented graben that cuts the summit and has at least 140 m of vertical displacement. The small Laguna de Maderas lake occupies the bottom of the 800-m-wide summit crater, which is located at the western side of the central graben. The SW side of the edifice has been affected by large-scale slumping. Many pyroclastic cones are situated on the lower NE flank down to the level of Lake Nicaragua. The latest period of major growth of Maderas took place more than 3000 years ago. No confirmed historical eruptions are known from the volcano. A lahar in September 1996 killed six persons in an east-flank village, but associated volcanic activity was not confirmed.

Estelí
Fissure vents
Fresh-looking, sparsely vegetated lava flows mostly erupted from fissure vents are located in valleys in the northern interior highlands between the town of Estelí and the border with Honduras. McBirney and Williams (1965) considered basaltic flows in this area to be certainly of Quaternary, and possibly of Holocene age. The lava flows near Estelí were faulted and slightly tilted during formation of the Estelí structural basin. Other youthful basaltic lava flows, one of which was erupted from the Bonete de Carrao cone, are located between Estelí and Jinotega. Well-preserved cones are also located in the area west and south of Ocotal. Some of the youthful lava flows in northern Nicaragua contain granitic xenoliths and xenocrysts of quartz.

Cerro el Ciguatepe
Cerro el Ciguatepe is one of several Quaternary volcanoes that lie in the Nicaraguan interior highlands, east of the Nicaraguan depression. The steep-sided stratovolcano was constructed east of the Río Pacora, NE of Lake Managua at the boundary of the flat-lying Tertiary ignimbrite deposits with the fault-blocks bordering the Nicaraguan depression. A small lava flow extends a short distance beyond the base of the cone through a breach in the SW wall of the well-preserved 1.5-km-wide crater. A blocky plug dome occupies the center of the crater. The relatively well-preserved Cerro el Ciguatepe cone is morphologically similar to the youthful cones of the Nejapa alignment (van Wyk de Vries 1999, pers. comm.) and may be of Holocene age.

Las Lajas
Las Lajas is the largest volcano of possible Quaternary age east of the Nicaraguan graben. The broad, low, basaltic shield volcano is truncated by a 7-km-wide, steep-walled caldera. The 650-m-deep caldera is breached by a narrow canyon on the SE side that drains into Lake Nicaragua. Five coalescing andesitic-dacitic lava domes are located in the center of the caldera, and additional domes are present on the outer flanks. Las Lajas was considered to be of Holocene age on the basis of youthful morphology (McBirney and Williams, 1965), however Plank et al. (2002) obtained three radiometric dates of Miocene age, and the main edifice may be older than previously thought. Van Wyk de Vries (1999, pers. comm.) earlier noted that Las Lajas itself was of probable Pleistocene age, but that youthful cinder cones on the flanks are similar to those of the Nejapa alignment and may be of Holocene age.

Volcán Azul
Volcán Azul (Volcán Blue) consists of three youthful cinder cones on the jungle-covered Atlantic coastal plain of Nicaragua that were first noted by geologists during an aerial overflight in the 1960s. The three cones, located south of the Río Curinhuás and west of Pearl Lagoon, each have well-defined, steep-walled craters about 50-60 m across. In contrast to the circular rims of the other two cones, the rim of the easternmost cone is breached to the west. The well-defined craters and unusually low vegetation in an area of heavy rainfall and rapid weathering led Williams and McBirney (1965) to estimate that the cones were probably no more than a few thousand years old.

Costa Rica

Orosí
Costa Rica
Orosí is one of a cluster of four eroded and vegetated cones in the Guanacaste Range at the NW corner of Costa Rica. Volcán Orosí itself has a conical shape as viewed from the north or west, but its flanks are heavily eroded. The complex includes Orosí, Orosilito, Volcán Pedregal, and Cacao. The highest peak of the volcanic complex is 1659-m-high Volcán Cacao, 5.5 km SE of Orosí. The summit of Cacao is cut by two large horseshoe-shaped calderas breached to the SW and east related to edifice collapse. The age of the latest activity of the Orosí complex is not known. Historical eruptions were reported from Orosí in 1844 and 1849, but even at the time of the first volcanological observations at the end of the 19th century, Orosí was overgrown with large trees, and the eruptions may actually have been from neighboring Rincón de la Vieja volcano. The latest documented volcanic activity at Orosí produced mudflows (perhaps secondary) about 3500 years ago.
Smithsonian Volcano Information | OVSICORI-UNA, Costa Rica | OSIVAM-ICE, Costa Rica

Rincón de la Vieja
Costa Rica
Rincón de la Vieja, the largest volcano in NW Costa Rica, is a remote volcanic complex in the Guanacaste Range. The volcano consists of an elongated, arcuate NW-SE-trending ridge that was constructed within the 15-km-wide early Pleistocene Guachipelín caldera, whose rim is exposed on the south side. Rincón de la Vieja, sometimes known as the "Colossus of Guanacaste," has an estimated volume of 130 cu km and contains at least 9 major eruptive centers. Activity has migrated to the SE, where the youngest-looking craters are located. The twin cone of 1916-m-high Santa María volcano, the highest peak of the Rincón complex, is located at the eastern end of a smaller, 5-km-wide caldera and has a 500-m-wide crater. A plinian eruption producing the 0.25 cu km Río Blanca tephra about 3500 years ago was the last major magmatic eruption from the volcano. All subsequent eruptions, including numerous historical eruptions possibly dating back to the 16th century, have been from the prominent crater containing a 500-m-wide acid lake (known as the Active Crater) located ENE of Von Seebach crater.
Smithsonian Volcano Information | OVSICORI-UNA, Costa Rica | OSIVAM-ICE, Costa Rica

Miravalles
Miravalles is a 2028-m-high andesitic stratovolcano that is one of five post-caldera cones along a NE-trending line within the broad 15 x 20 km Guayabo (Miravalles) caldera. The caldera was formed during several major explosive eruptions that produced voluminous dacitic-rhyolitic pyroclastic flows between about 1.5 and 0.6 million years ago. Growth of post-caldera volcanoes in the eastern part of the caldera that overtopped much of the eastern and southern caldera rims was interrupted by edifice collapse that produced a major debris avalanche to the SW. Morphologically youthful lava flows cover the western and SW flanks of the post-caldera Miravalles complex, which rises above the town of Guayabo on the flat western caldera floor. The only reported historical eruptive activity was a small steam explosion on the SW flank in 1946. High heat flow remains, and Miravalles is the site of the largest developed geothermal field in Costa Rica.
Smithsonian Volcano Information | OVSICORI-UNA, Costa Rica | OSIVAM-ICE, Costa Rica

Tenorio
The 225 sq km dominantly andesitic Tenorio volcanic massif anchors the SE end of the Guanacaste Range and consists of a cluster of densely forested NNW-SSE-trending volcanic cones. Overlapping lava flows from the principal peak, Tenorio, blanket the NW-to-SW flanks and descend the NE flank. The NW-most of three craters of the central cone is sparsely vegetated and appears to be the most recently active. Volcán Montezuma to the north has twin craters, the northern of which fed a lava flow to the NE. Additional pyroclastic cones are found to the NE and SW of the central complex, and the Bijagua lava domes were constructed on the northern flank. A major debris avalanche covered about 100 sq km below the southern flank of the volcano. A legend exists of an eruption in 1816, but the volcano was densely forested at the time of an 1864 visit by Seebach and is not considered to have erupted in historical time. Fumarolic activity is present on the NE flank.

Arenal
Conical Volcán Arenal is the youngest stratovolcano in Costa Rica and one of its most active. The 1670-m-high andesitic volcano towers above the eastern shores of Lake Arenal, which has been enlarged by a hydroelectric project. Arenal lies along a volcanic chain that has migrated to the NW from the late-Pleistocene Los Perdidos lava domes through the Pleistocene-to-Holocene Chato volcano, which contains a 500-m-wide, lake-filled summit crater. The earliest known eruptions of Arenal took place about 7000 years ago, and it was active concurrently with Cerro Chato until the activity of Chato ended about 3500 years ago. Growth of Arenal has been characterized by periodic major explosive eruptions at several-hundred-year intervals and periods of lava effusion that armor the cone. Arenal's most recent eruptive period began with a major explosive eruption in 1968. Continuous explosive activity accompanied by slow lava effusion and the occasional emission of pyroclastic flows has occurred since then from vents at the summit and on the upper western flank.

Platanar
The Platanar volcanic center is the NW-most volcano in the Cordillera Central of Costa Rica. The massive complex covers about 900 sq km and is dominated by two largely Pleistocene stratovolcanoes, Platanar and Porvenir. These volcanoes were constructed within the Pleistocene Chocosuela caldera, which may have formed during a major slope failure. The 2183-m-high Cerro Platanar volcano (known locally as Volcán Congo) on the north side of the complex has prehistorical lava flows on its western flanks and is the youngest volcanic center. The highest peak of the complex is 2267-m-high Porvenir volcano, whose summit crater lies 3 km south of Platanar. A thin layer of phreatic ash suggested that an eruption from Platanar occurred within the past few thousand years (Stine and Banks, 1991). The Aguas Zarcas group of nine basaltic cinder cones, located on the north flank of the Platanar-Porvenir complex to as low as 160 m altitude, is in part Holocene in age.

Poás
The broad, well-vegetated edifice of Poás, one of the most active volcanoes of Costa Rica, contains three craters along a N-S line. The frequently visited multi-hued summit crater lakes of the basaltic-to-dacitic volcano, which is one of Costa Rica's most prominent natural landmarks, are easily accessible by vehicle from the nearby capital city of San José. A N-S-trending fissure cutting the 2708-m-high complex stratovolcano extends to the lower northern flank, where it has produced the Congo stratovolcano and several lake-filled maars. The southernmost of the two summit crater lakes, Botos, is cold and clear and last erupted about 7500 years ago. The more prominent geothermally heated northern lake, Laguna Caliente, is one of the world's most acidic natural lakes, with a pH of near zero. It has been the site of frequent phreatic and phreatomagmatic eruptions since the first historical eruption was reported in 1828. Poás eruptions often include geyser-like ejections of crater-lake water.

Barva
The central and least known of three massive volcanoes towering over the capital city of San José, Volcán Barva (Barba) is a complex volcano with multiple summit and flank vents. Its three principal summits visible from the Central Valley give it the common local name of Las Tres Marías. The voluminous andesitic-to-dacitic Tiribí Tuff, exposed in the Central Valley of Costa Rica, was erupted about 322,000 years ago from the Barva summit caldera. Four pyroclastic cones are constructed within the 2 x 3 km caldera at the central and NW part of the summit. The SW peak contains four cones, one of which has a crater lake. Satellitic cones are found on the northern and southern flanks. Lava flows blanket the south side of Barva volcano. The Los Angeles flow, one of the most recent, descends nearly to the city of Heredia. A large plinian eruption occurred at Barva during the early Holocene. Eruptions were reported in 1760 or 1766, 1776? (also a mudflow), and 1867, but later visits to the summit did not provide evidence of eruptions during historical time.

Irazú
Irazú, Costa Rica's highest volcano and one of its most active, rises to 3432 m immediately east of the capital city of San José. The massive volcano covers an area of 500 sq km and is vegetated to within a few hundred meters of its broad flat-topped summit crater complex. At least 10 satellitic cones are located on the southern flank of Irazú. No lava flows have been identified from Irazú since the eruption of the massive Cervantes lava flows from south-flank vents about 14,000 years ago, and all known Holocene eruptions have been explosive. The focus of eruptions at the summit crater complex has migrated to the west towards the historically active crater, which contains a small lake of variable size and color. Although eruptions may have occurred around the time of the Spanish conquest, the first well-documented historical eruption occurred in 1723, and frequent explosive eruptions have occurred since. Ashfall from the last major eruption of Irazú during 1963-65 caused significant disruption to San José and surrounding areas.

Turrialba
Turrialba, the easternmost of Costa Rica's Holocene volcanoes, is a large vegetated basaltic-to-dacitic stratovolcano located across a broad saddle NE of Irazú volcano overlooking the city of Cartago. The massive 3340-m-high Turrialba is exceeded in height only by Irazú, covers an area of 500 sq km, and is one of Costa Rica's most voluminous volcanoes. Three well-defined craters occur at the upper SW end of a broad 800 x 2200 m wide summit depression that is breached to the NE. Most activity at Turrialba originated from the summit vent complex, but two pyroclastic cones are located on the SW flank. Five major explosive eruptions have occurred at Turrialba during the past 3500 years. Turrialba has been quiescent since a series of explosive eruptions during the 19th century that were sometimes accompanied by pyroclastic flows. Fumarolic activity continues at the central and SW summit craters.

Panamá

Barú
Panamá
The westernmost volcano in Panamá, Barú, is a complex dominantly andesitic stratovolcano in the Talamanca Range near the Costa Rica border. The forested 3474-m-high Volcán Barú (also referred to as Volcán de Chiriqui) is the highest peak in Panamá, and the summit now bristles with communication towers. A large 6-km-wide summit caldera breached widely to the west was formed by a large volcanic landslide, which created a massive debris-avalanche deposit that extends onto the Pacific coastal plain. Post-collapse eruptions have constructed lava domes inside the caldera that have grown to a height exceeding that of the caldera rim. A strong explosive eruption at about 700 AD ended human occupation at the Cerro Punta archaeological site NW of the volcano. Montessus de Ballore (1884) reported a strong eruption at Barú in the mid-16th century. Sapper (1917) considered this report to be uncertain, but radiocarbon dates subsequently imply tephra deposits younger than about 500 years. Volcán Barú is the youngest major volcano in Panamá, and geothermal exploration projects have been undertaken to determine its energy potential.

La Yeguada
Panamá
La Yeguada, also known as Chitra-Calobre, is a massive volcanic complex in west-central Panamá north of the Azuero Peninsula that was active from the Miocene into the Quaternary. The youngest major feature of La Yeguada is located within a large fault-bounded horst that forms the high point of the volcanic complex east of Laguna La Yeguada. The latest eruptions took place from the northern part of the horst about 220,000 years ago at Cerro Corero lava dome (also known as Cerro de la Charca), north of El Castillo. The youngest feature of the La Yeguada complex is the Media Luna cinder cone, which was erupted through Tertiary ignimbrite deposits at the NW side of the complex. The oldest peat layer within a small lake dammed by a basaltic lava flow originating from the cone was radiocarbon dated at about 300-350 years ago. Warm springs are scattered throughout the complex, and the Chitra-Calobre geothermal field is one of three areas in Panamá that have been the object of intensive geothermal exploration.

El Valle
El Valle volcano, 80 km SW of Panama City, is a broad stratovolcano cut by a large compound Pleistocene caldera. The 6-km-wide El Valle de Antón caldera was formed about 1.1-1.3 million years ago. It has steep, 200-300 m high walls overlooking a flat floor underlain by deposits of a former caldera lake and currently occupied by the town of El Valle. Cerro Pajita, Cerro Gaital, and Cerro Caracoral form a dacitic lava dome complex that was constructed along an E-W-trending lineament within the caldera and forms the 1185 m high point of the volcano. Major phreatomagmatic plinian eruptions produced when magma interacted with caldera-lake water as recently as about 34,600 years ago generated pyroclastic flows that reached the Pacific coast, 25 km to the south. Phreatic eruptions have occurred since then (the most recent dated eruption took place about 13,000 years ago), and activity may have continued into the Holocene (IRHE, 1987). A geothermal exploration program is currently underway to evaluate the energy potential of the caldera.

Plaques tectoniques
Limites des Plaques tectoniques à n'observer qu'à une altitude de + de 1000 km
Cliquer ici pour accéder à This Dynamic Earth.
.L'histoire de la tectonique des plaques.

legende

Noms des plaques

Plaque africaine

Plaque Antarctique

Plaque Arabique

Plaque Australienne

Burma Plate

Plaque Caraîbes

Plaque Cocos

Plaque Eurasienne

Plaque Indienne

Paque Juan de Fuca

Plaque Nord Americaine

Plaque de Nazca

Plaque d'Okhotsk

Plaque Pacifique

Plaque des Philippine

Paque Rivera

Plaque Scotia

Plaque Sud Américaine

limites des plaques
Tectonic Plate Boundaries, detailed (US Geological Survey). from

Continental Rift Boundary

Oceanic Spreading Rift

Continental Transform Fault

Oceanic Transform Fault

Continental Convergent Boundary

Oceanic Convergent Boundary

Subduction Zone

Plate Convergence

Convergence Arrows

39 mm/yr
Convergence data are shown by arrows describing direction and speed, relative to the plate across the boundary.
For more information, see This Dynamic Planet.

58 mm/yr
Convergence data are shown by arrows describing direction and speed, relative to the plate across the boundary.
For more information, see This Dynamic Planet.

73 mm/yr
Convergence data are shown by arrows describing direction and speed, relative to the plate across the boundary.
For more information, see This Dynamic Planet.

Des sismogrammes
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Balises GPS
Il existe à la surface du globe des stations qui enregistrent leur position en latitude et en longitude grace au GPS (Global Positioning Sytem)
Sur les graphes, chaque point correspond à un enregistrement et une pente positive indique un déplacement vers le Nord ou vers l'Est et une pente négative un déplacement vers le Sud ou vers l'Ouest.
"Qu'est-ce que le GPS (anglais)"
Ensemble des stations GPS de la NASA : "NASA - GPS Time Series"

Plaque caraïbe

BARB
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Cliquer ici pour obtenir les enregistrements

GUAT
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JAMA

MOIN

TEGU

Plaque Nord Américaine

ELEN

KYVW

SCUB

Caraïbes
Carte géologique Extrait CCGM

Carte géologique des Caraïbes

Age de la croute océanique

Roches continentales

Carte topographique à proximité de l'épicentre
WFP/OMEP and ITOS
Topographic detail around the epicenter of the January 2010 earthquake in Haiti, including high resolution contours and rough population density.
Map compiled by WFP Emergency Preparedness Branch (OEMP) Jan 12, 2010
Topo data courtesy of ITOS.
Datasset processed and kml provided by Matt Fox at http://www.gelib.com
Note: geo-referencing of map may not be exact. For informational purposes only, not verified on the ground.

L'alea sismique en Haïti - Cadre géographique et temporel
par Eric Palais, Purdue universite
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Soyez patient, l'ouverture du document est un peu long.