No latest activity reported for Alamagan.

Below is a summary of eruption dates and Volcanic Explosivity Indices (VEI).

The following references are the sources used for data regarding this volcano. References are linked directly to our volcano data file. Discussion of another volcano or eruption (sometimes far from the one that is the subject of the manuscript) may produce a citation that is not at all apparent from the title. Additional discussion of data sources can be found under Volcano Data Criteria.

Bloomer S H, Stern R J, Smoot N C, 1989. Physical volcanology of the submarine Mariana and Volcano arcs. {Bull Volc}, 51: 210-224

Corwin G, 1971. Quaternary volcanics of the Mariana Islands. {Unpublished manuscript}, 137 p

Katsui Y (ed), 1971. List of the World Active Volcanoes. {Volc Soc Japan draft ms}, (limited circulation), 160 p

Kuno H, 1962. Japan, Taiwan and Marianas. {Catalog of Active Volcanoes of the World and Solfatara Fields}, Rome: IAVCEI, 11: 1-332

Meijer A, Reagan M, 1983. Origin of K2O-SiO2 trends in volcanoes of the Mariana arc. {Geology}, 11: 67-71

Moore R B, Trusdell F A, 1993. Geologic map of Alamagan volcano, northern Mariana Islands. {U S Geol Surv Map I-2408}, 1:12,500 scale

Alamagan is the emergent summit of a large stratovolcano in the central Mariana Islands with a roughly 350-m-deep summit crater east of the center of the island. The exposed cone is largely Holocene in age. A 1.6 x 1 km graben cuts the SW flank. An extensive basaltic-andesite lava flow has extended the northern coast of the island, and a lava platform also occurs on the south flank. Pyroclastic-flow deposits erupted about 1000 years ago have been dated, but reports of historical eruptions were considered invalid (Moore and Trusdell, 1993).