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A single large asymmetrical stratovolcano, steeper on the NE side, forms 3-km-wide Asuncion Island.

Quick Facts

Location: Commonwealth of the Northern Mariana Islands

Latitude: 19.671° N

Longitude: 145.406° E

Elevation: 857 (m) 2,812 (f)

Volcano type: Stratovolcano

Composition: Andesite

Most recent eruption: 1906 CE

Threat Potential: Moderate*

*based on the National Volcano Early Warning System


Asuncion Island Volcano photo by Annette DesRochers of NOAA
Photo of Asuncion Island Volcano. 

A single large asymmetrical stratovolcano, steeper on the NE side, forms 3-km-wide Asuncion Island. The steep NE flank of the 857-m-high volcano terminates in high sea cliffs. The gentler SW flanks have low-angle slopes bounded by sea cliffs only a few meters high. The southern flank is cut by a large landslide scar. The southern flanks and western flanks are mantled by ash deposits that may have originated during eruptions in historical time. An explosive eruption in 1906 also produced lava flows that descended about half way down the western and SE flanks, but several other historical eruption reports are of uncertain validity. Few invesitgations have been done on the Cheref and Poyo seamounts, 30 and 50 km SE, respectively. From the Smithsonian Global Volcanism Program.


Volcanic hazards in the Pacific U.S. Territories

The Commonwealth of the Northern Mariana Islands, Guam, and American Samoa lie along the western side of the famed Pacific Ring of Fire. Here, the processes of active island and submarine volcanoes produce activity both underwater and in the atmosphere that poses potential hazards to the daily lives of residents and travelers. Since 2000, CNMI volcanoes have erupted six times, and one submarine vo
Gabrielle Tepp, Brian Shiro, William W. Chadwick

2018 update to the U.S. Geological Survey national volcanic threat assessment

When erupting, all volcanoes pose a degree of risk to people and infrastructure, however, the risks are not equivalent from one volcano to another because of differences in eruptive style and geographic location. Assessing the relative threats posed by U.S. volcanoes identifies which volcanoes warrant the greatest risk-mitigation efforts by the U.S. Geological Survey and its partners. This update

John W. Ewert, Angela K. Diefenbach, David W. Ramsey

Volcanic investigations in the Commonwealth of the Northern Mariana Islands, April to May 1994

A team of U.S. Geological Survey geologists, a seismologist, and technicians gathered new geologic, seismic, and deformation data in the Commonwealth of the Northern Mariana Islands (CNMI). Nine volcanic islands on the active East Mariana Ridge north of Saipan were examined between April 20 and May 3, 1994. In addition, a new radio-telemetry seismic station was installed on the island of Agrihan (

M. K. Sako, F. A. Trusdell, R. Y. Koyanagi, George Kojima, R. B. Moore