Volcano Information

    Alamagan
    Volcanic Alert Level: UNASSIGNED Aviation Color Code: UNASSIGNED

    • Volcanic History Overview: 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). From the Smithsonian Global Volcanism Program.
    • Location: Mariana Islands, Mariana Islands

      Latitude: 17.6
      Longitude: 145.83
      Elevation: 744 m

      Recent Eruption: 1000 years ago
    • Hazard Assessments: Sako, M. K.; Trusdell, F. A.; Koyanagi, R. Y.; Kojima, George; Moore, R. B., 1995, Volcanic investigations in the Commonwealth of the Northern Mariana Islands, April to May 1994, USGS Open-File Report 94-705.
    • Link to monitoring data: NMI Web Site