Volcanoes on the Mariana Islands are mainly stratovolcanoes. It is located in the western part of the Pacific Ocean, stretching from Hawaii to the Philippines. The collision of the Pacific plate and the Philippine plate created the Mariana trench and the islands with the volcanoes. The Northern islands have active volcanoes. The islands Anatahan, Asuncion, Pagan, and Farallon de Pajaros were formed by lava overflow.

Anatahan

The most active volcano on the Mariana Islands is Anatahan. It has the largest known caldera on the islands, with a crater in the middle of the caldera, formed during its first eruption on May 10, 2003. Anatahan created earthquakes and typhoons leading up to this eruption. It blew clouds of ash to about 6 kilometers. Small amounts of ash had fallen onto the other islands. Anatahan has explosive eruptions, and rhyolitic lava. Its frequent eruptions caused the island to be evacuated and nobody lives there anymore.
Anatahan is capable of producing very large eruptions, with pyroclastic flows and higher ash clouds causing more ash to fall on the surrounding islands. Eruptions from Anatahan cause little damage seeing as it is not populated.

Neighboring Volcanoes:

Agrihan: stratovolcano, 965 meters, only eruption in 1917
Alamagan: stratovolcano, 744 meters
Asuncion: stratovolcano, 861 meters, last erupted in 1906, explosive eruption
Farallon de Pajaros: stratovolcano, 360 meters, last erupted in 1967.
Guguan: has two volcanoes, only one is active, stratovolcano, 287 meters, erupted between 1819 and 1901, most famous eruption between 1802 and 1804 created northern volcano.
Maug Islands: stratovolcano, 227 meters, no known eruptions
Pagan: two stratovolcanoes, 570 meters, largest eruption in 1981 led to evacuation of island, last erupted in 2006.
Sarigan: stratovolcano, 538 meters

Other sites on Anatahan:

http://hvo.wr.usgs.gov/volcanowatch/2003/03_05_15.html

http://www.volcano.si.edu/world/

Bibliography

www.volcanolive.com/mariana.html
volcano.oregonstate.edu/vwdocs/volc_images/southeast_asia/mariana/basic_geology.html
http://hvo.wr.usgs.gov/volcanowatch/2003/03_05_15.html

Pacific Islands, Katherine Kristen

http://www.volcano.si.edu/world/region.cfm?rnum=0804