Volcano Information
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Agrigan
- Current Update, last updated Jan 25, 2013 11:09 ChST:
In a satellite image from January 22, NOAA's Washington Volcanic Ash Advisory Center spotted a possible volcanic plume from Agrigan. Neither USGS nor NOAA have received confirmation of a volcanic source for this anomaly and it is likely the cloud was weather-related.
Agrigan, the next island volcano north of Pagan, is a stratovolcano truncated by a mile-wide caldera. The only known eruption in 1917 was a significant explosive event that buried a village in more than three feet of ash. There are no ground-based monitoring instruments on Agrigan. 
Volcanic History Overview: The highest of the Marianas arc volcanoes, Agrigan contains a 500-m-deep, flat-floored caldera. The elliptical island is 8 km long; its 965-m-high summit is the top of a massive 4000-m-high submarine volcano, the second largest in the Marianas Islands. Deep radial valley dissect the flanks of the thickly vegetated stratovolcano. The elongated caldera is 1 x 2 km wide and is breached to the NW, from where a prominent lava flow extends to the coast and forms a lava delta. The caldera floor is surfaced by fresh-looking lava flows and also contains two cones that may have formed during the volcano's only historical eruption in 1917. This eruption deposited large blocks and 3 m of ash and lapilli on a village on the SE coast, prompting its evacuation. (from the Smithsonian Global Volcanism Program)
Location: Mariana Islands, Mariana Islands
Latitude: 18.77
Longitude: 145.67
Elevation: 965 m
Recent Eruption: 1917- 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
Volcanic Alert Level: UNASSIGNED Aviation Color Code: UNASSIGNED
