OREGON STATE UNIVERSITY

Stratovolcano

Asama

Latitude (dd): 
36.40
Longitude (dd): 
138.53
Elevation (m): 
2568
Country: 
Japan
State (Province, etc): 
Honshu
Type: 
Complex Volcano

 

 

A temple sits astride the Onioshidashi lava flow on the north flank of Asama volcano.
Photo by Richard Fiske, 1961 (Smithsonian Institution).

Asama, Honshu's most active volcano, overlooks the resort town of Karuizawa, 140 km NW of Tokyo. The volcano is located at the junction of the Izu-Marianas and NE Japan volcanic arcs. Asama is Honshu's most active volcano, and has an historical record dating back more than 1300 years.

Asama is a stratovolcano. Three overlapping bodies make up this volcano. It consists of a young stratovolcano with two craters lying on a shield volcano. The shield volcano rests on an older stratovolcano.

Kurohu-yama is the name of the western crater rim of the older stratovolcano. It stands 7888 ft (2405 m) high. Erosion has enlarged this crater to 1.25 miles (2 km) around. Water rests in the crater and is drained to the southwest. The eastern part of this stratovolcano has been down-faulted and buried under a shield volcano. A younger stratovolcano also lies on top of this shield.

Asacha

Latitude (dd): 
52.36
Longitude (dd): 
157.83
Elevation (m): 
1910
Country: 
Russia
State (Province, etc): 
Kamchatka
Type: 
Stratovolcano

 

 

 

Asacha is a composite stratovolcano that is made up of several extinct cones. Its best preserved crater is located on the south-eastern most cone. Asacha is located north of Khodutka and over time has been eroded into four summits, which have inner slopes that are steep and rocky. Pyroclastic flows from Asacha form a large pumice plain around it. Asacha has never erupted in historical times.

 

 

 

 

 

Some other volcanoes that are located in this general area include: Opala, Gorely and Mutnovsky.

 

 

 

 

Sources of Information:

Kozhemyaka, N.N., "Quaternary Pumice Tuff-Ignimbrite Fields and Centers of Eruption in Southern Kamchatka," Akad Nauk USSR, Bulletin of Volcanology, Station No. 57, 1979.

Arenal

Latitude (dd): 
10.46
Longitude (dd): 
-84.70
Elevation (m): 
1670
Country: 
Costa Rica
Type: 
Stratovolcano

 

Conical Volcan Arenal is the youngest stratovolcano in Costa Rica and one of its most active. The 1657-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.


Photo by Scott Rowland.

Ararat

Latitude (dd): 
39.70
Longitude (dd): 
44.30
Elevation (m): 
5165
Country: 
Turkey
Type: 
Stratovolcano

 


Space Shuttle Image taken 9.14.94. Image Credit: NASA

Ararat is the largest and highest volcano in Turkey. Ararat is a stratovolcano. In the above image, north is to the lower left. The border with Armenia is 10 miles (16 kilometers) from the summit and is roughly along the left edge of the image. Ararat has not erupted in historic time. The most recent eruption was probably in the last 10,000 years. The volcano is thought to be the resting place of Noah's ark. The observation of vessel-shaped features in aerial photographs of Ararat caused a stir in the late 1950s. Expeditions found the features to be landslides and lava flows.

The cause of volcanism in eastern Turkey has not been established. Some geologists argue that the Arabian plate is being subducted beneath the Eurasian plate. However, the region lacks moderate and deep earthquake activity common to most subduction zones. An alternative model proposes renewed subduction of continental lithosphere. A third model proposes that volcanism is related to shear along the contact of the two plates.

 

Antisana

Latitude (dd): 
-0.48
Longitude (dd): 
-78.14
Elevation (m): 
5753
Country: 
Ecuador
Type: 
Stratovolcano

 

 

 

Aneityum

Latitude (dd): 
-20.20
Longitude (dd): 
169.78
Elevation (m): 
852
Country: 
Vanuatu
Type: 
Stratovolcano

Sources of information on the volcanoes of Vanuatu (New Hebrides Islands).

Department of Geology, Mines and Water Resources, Vanuatu.
ORSTOM assists with the monitoring of the active volcanoes in Vanuatu.

Crawford, A.J., Greene, H.G., and Exon, N.F., 1988, Geology, petrology, and geochemistry of submarine volcanoes around Epi Island, New Hebrides island arc in Greene, H.G., and Wong, F.L., eds., Geology and Offshore Resources of Pacific Island Arcs-Vanuatu Region, Circum-Pacific Council Energy Min. Resource Earth Sci. Ser., 8: p. 301-307.

Colley, H., and Warden, A.J., 1974, Petrology of the New Hebrides: Geological Society of America Bulletin, v. 85, p. 1635-1646.

Fisher, N.H., 1957, Part V, Melanesia: Catalogue of the active volcanoes of the world, International Association of Volcanology, Rome, Italy, 105 p.

Kibblewhite, A.C., 1966, The acoustic detection and location of an underwater volcano [unnamed SW pacific volcano]: New Zealand Journal of Science, v. 9, p. 178-199.

McCall, G.J.H., LeMaitre, R.W., Malahoff, A., Robinson, G.P., and Stephenson, P.J., 1970, The geology and geophysics of the Ambrym Caldera, New Hebrides: Bulletin Volcanology, v. 34, p. 681-696.

Anatahan

Latitude (dd): 
16.35
Longitude (dd): 
145.67
Elevation (m): 
790
Country: 
Mariana Islands
Type: 
Stratovolcano

 

The two coalescing volcanoes forming the elongated, 9-km-long island of Anatahan in the central Mariana Islands are apparent in this aerial view from the south. The low point in the center of the island results in part from overlapping 2.3 x 5 km wide calderas, the largest in the Mariana Islands. The larger western caldera is 2.3 x 3 km wide and extends eastward from the 788-m-high summit of the western volcano (left). The volcano's first historical eruption in 2003 took place from a small crater within the 2-km-wide eastern caldera.  Photo by U.S. Geological Survey, 1994.

 


 

Alid

Latitude (dd): 
14.88
Longitude (dd): 
39.92
Elevation (m): 
904
Country: 
Eritrea
Type: 
Stratovolcano

 

 

 

 

 

Alid is a little-visited volcanic structure in the Danakil depression of Eritrea and covers an area of about 20 sq. miles (30 sq Km). Based on brief visits by Italian geologists early this century Alid was thought to be a stratovolcano with a broad caldera, and basaltic lava fields on its northwest and southeast slopes. New studies by US Geological Survey scientists and Eritrean colleagues show that Alid is actually a structural uplift - a dome - whose summit has collapsed. There have also been explosive eruptions which deposited pyroclastic flows around the uplift. So Alid is a very peculiar type of volcano-tectonic structure.

Alid has been very important geographically. Before Alid was uplifted the Red Sea covered part of Afar. After the Alid activity the sea could not enter Afar and gradually the water there evaporated, leaving behind vast plains of white salts.

 

 

 

 

 

 

 

Ale Bagu

Latitude (dd): 
13.52
Longitude (dd): 
40.63
Elevation (m): 
1031
Country: 
Ethiopia
Type: 
Stratovolcano

Alamagan

Latitude (dd): 
17.60
Longitude (dd): 
145.83
Elevation (m): 
744
Country: 
Mariana Islands
Type: 
Stratovolcano

Alamagan is a stratovolcano about 30 km south of the island of Pagan.
Two historic eruptions are suspected in 1864 and 1887.
Photograph by Norm Banks, U.S. Geological Survey, May, 1981.

Alamagan, looking to the southeast. Photograph by Frank Trusdell, U.S. Geological Survey.

 

The Mariana Islands are a classic example of an island arc, a curved line of stratovolcanoes that rise up from the ocean floor.


The Mariana trench, ridge, and islands. Based on Schmidt (1957), U.S. Geological Survey.

The islands owe their origin to subduction, the tectonic process that thrusts one plate beneath another.


Simplified cross-section of the subduction zone of the Mariana arc.