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Maug Islands

Find U.S. Volcano

Three small elongated islands up to 2.3 km long mark the northern, western, and eastern rims of a largely submerged 2.5-km-wide caldera. 

Quick Facts

Location: Commonwealth of the Northern Mariana Islands
Latitude: 20.02° N
Longitude: 145.22° E
Elevation: 227 (m) 745 (f)
Volcano type: Stratovolcano
Composition: Basalt - Dacite
Most recent eruption: Unrest in the Holocene
Threat Potential: Low/Very Low*

*based on the National Volcano Early Warning System

Summary

Maug Island Volcano
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Maug Islands Volcano.

Three small elongated islands up to 2.3 km long mark the northern, western, and eastern rims of a largely submerged 2.5-km-wide caldera. The highest point of the Maug Islands reaches only 227 m above sea level; the submerged southern notch on the caldera rim lies about 140 m below sea level. The caldera has an average submarine depth of about 200 m and contains a twin-peaked central lava dome that rises to within about 20 m of the sea surface. The Maug Islands form a twin volcanic massif with Supply Reef, about 11 km N. The truncated inner walls of the caldera on all three islands expose lava flows and pyroclastic deposits that are cut by radial dikes; bedded ash deposits overlie the outer flanks of the islands. No eruptions are known since the discovery of the islands by Espinosa in 1522. The presence of poorly developed coral reefs and coral on the central lava dome suggests a long period of general quiescence, although it does not exclude mild eruptions. A 2003 NOAA expedition detected possible evidence of submarine geothermal activity. From the Smithsonian Global Volcanism Program.

Publications

Volcanic hazards in the Pacific U.S. Territories

The Commonwealth of the Northern Mariana Islands, Guam, and American Samoa lie along the western side of the famed Pacific Ring of Fire. Here, the processes of active island and submarine volcanoes produce activity both underwater and in the atmosphere that poses potential hazards to the daily lives of residents and travelers. Since 2000, CNMI volcanoes have erupted six times, and one submarine vo
Authors
Gabrielle Tepp, Brian Shiro, William W. Chadwick
By
Volcano Hazards Program, Volcano Science Center, Agrigan, Ahyi Seamount, Alamagan, Anatahan, Asuncion, Daikoku Seamount , East Diamante, Esmeralda Bank, Farallon de Pajaros, Fukujin Seamount , Guguan, Kasuga 2, Maug Islands, Ofu-Olosega, Pagan, Ruby, Sarigan, South Sarigan Seamount, Supply Reef, Ta'u Island, Tutuila Island, Zealandia Bank, Subduction Zone Science

2018 update to the U.S. Geological Survey national volcanic threat assessment

When erupting, all volcanoes pose a degree of risk to people and infrastructure, however, the risks are not equivalent from one volcano to another because of differences in eruptive style and geographic location. Assessing the relative threats posed by U.S. volcanoes identifies which volcanoes warrant the greatest risk-mitigation efforts by the U.S. Geological Survey and its partners. This update

Authors
John W. Ewert, Angela K. Diefenbach, David W. Ramsey
By
Volcano Hazards Program, Volcano Science Center, Agrigan, Ahyi Seamount, Alamagan, Anatahan, Asuncion, Belknap, Black Butte Crater Lava Field, Black Rock Desert Volcanic Field, Blue Lake Crater, Carrizozo Lava Flow, Cascade Range Weekly Update, Cinnamon Butte, Clear Lake Volcanic Field, Coso Volcanic Field, Crater Lake, Craters of the Moon Volcanic Field, Daikoku Seamount , Davis Lake Volcanic Field, Devils Garden Lava Field, Diamond Craters Volcanic Field, Dotsero Volcanic Center, East Diamante, Esmeralda Bank, Farallon de Pajaros, Fukujin Seamount , Glacier Peak, Guguan, Haleakalā, Hell's Half Acre Lava Field, Hualālai, Indian Heaven Volcanic Field, Jordan Craters Volcanic Field, Kama‘ehuakanaloa, Kasuga 2, Kīlauea, Lassen Volcanic Center, Long Valley Caldera, Mammoth Mountain, Markagunt Plateau Volcanic Field, Maug Islands, Mauna Kea, Mauna Loa, Medicine Lake, Mono Lake Volcanic Field, Mono-Inyo Craters, Mount Adams, Mount Bachelor, Mount Baker, Mount Hood, Mount Jefferson, Mount Rainier, Mount Shasta, Mount St. Helens, Newberry, Ofu-Olosega, Pagan, Red Hill-Quemado Volcanic Field, Ruby, Salton Buttes, San Francisco Volcanic Field, Sand Mountain Volcanic Field, Sarigan, Soda Lakes, South Sarigan Seamount, Supply Reef, Ta'u Island, Three Sisters, Tutuila Island, Ubehebe Craters, Uinkaret Volcanic Field, Valles Caldera, Wapi Lava Field, Weekly Update, West Crater Volcanic Field, Yellowstone, Zealandia Bank, Zuni-Bandera Volcanic Field

Volcanic investigations in the Commonwealth of the Northern Mariana Islands, April to May 1994

A team of U.S. Geological Survey geologists, a seismologist, and technicians gathered new geologic, seismic, and deformation data in the Commonwealth of the Northern Mariana Islands (CNMI). Nine volcanic islands on the active East Mariana Ridge north of Saipan were examined between April 20 and May 3, 1994. In addition, a new radio-telemetry seismic station was installed on the island of Agrihan (

Authors
M. K. Sako, F. A. Trusdell, R. Y. Koyanagi, George Kojima, R. B. Moore
By
Natural Hazards Mission Area, Volcano Hazards Program, Volcano Science Center, Agrigan, Ahyi Seamount, Alamagan, Anatahan, Asuncion, Daikoku Seamount , East Diamante, Esmeralda Bank, Farallon de Pajaros, Fukujin Seamount , Guguan, Kasuga 2, Kīlauea, Maug Islands, Pagan, Ruby, Sarigan, South Sarigan Seamount, Supply Reef, Zealandia Bank
View All

Quick Facts

Location: Commonwealth of the Northern Mariana Islands
Latitude: 20.02° N
Longitude: 145.22° E
Elevation: 227 (m) 745 (f)
Volcano type: Stratovolcano
Composition: Basalt - Dacite
Most recent eruption: Unrest in the Holocene
Threat Potential: Low/Very Low*

*based on the National Volcano Early Warning System

Volcanoes Hazards Program Links