| Country: | United States | ||
| Subregion Name: | Mariana Islands | ||
| Volcano Number: | 0804-16= | ||
| Volcano Type: | Stratovolcano | ||
| Volcano Status: | Historical | ||
| Last Known Eruption: | 1917 | ||
| Summit Elevation: | 965 m | 3,166 feet | |
| Latitude: | 18.77°N | 18°46'0"N | |
| Longitude: | 145.67°E | 145°40'0"E | |
| 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. | |||