Ofu-Olosega | U.S. Geological Survey Official websites use .gov .gov website belongs to an official government organization in the United States. Secure .gov websites use HTTPS lock ( or means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites. Ofu-Olosega Find U.S. Volcano Filters The map displays volcanoes, earthquakes, monitoring instruments, and past lava flows. Get Help Earthquake Plots To view an earthquake cross-sectional plot, click "Draw Plot" to start drawing on the map. Once the plot area is selected, click on "View Plot" to view chart or "Clear Plot" to start over. Map Layers Earthquake Colors Earthquake Depth Units Earthquake Time Units Results Filters The map displays volcanoes, earthquakes, monitoring instruments, and past lava flows. Get Help Earthquake Plots To view an earthquake cross-sectional plot, click "Draw Plot" to start drawing on the map. Once the plot area is selected, click on "View Plot" to view chart or "Clear Plot" to start over. Settings Map Layers Earthquake Colors Earthquake Depth Units Earthquake Time Units Map Legend Map Legend Results Current Updates and Notifications Ofu-Olosega green NORMAL, 2026-04-02 18:49:22 UTC Update Search Recent Notifications Ofu-Olosega Volcano Updates Multimedia Publications News Connect Ofu and Olosega are two islands formed from two shield volcanoes in the United States Territory of American Samoa. Volcanic activity in American Samoa is within the area of responsibility of the U.S. Geological Survey’s Hawaiian Volcano Observatory, based in Hilo on the Island of Hawai‘i. Volcanoes in American Samoa Facts Block Location: American Samoa Latitude: 14.18° S Longitude: 169.62° W Elevation: 639 (m) 2,096 (f) Volcano type: Shield Composition: Basalt Most recent eruption: unknown Nearby towns: Olosega, Ofu Threat Potential: Low* *based on the National Volcano Early Warning System Hawaiian Volcano Observatory (HVO) The USGS Hawaiian Volcano Observatory monitors volcanoes in American Samoa Learn about HVO HVO Quick Links Volcanic Hazards in Pacific U.S. Territories Fact Sheet Volcanoes of American Samoa Fact Sheet Media Newsroom Subscribe to Volcano Updates Volcano Watch - HVO's weekly article Media Sources/Usage: Public Domain. View Media Details NASA Astronaut image of Ofu-Olosega islands (Manu'a Islands, American Samoa) in the South Pacific Ocean. NASA Space Shuttle image ISS002-E-6878 ( ). Photo & Video Chronology – August 28-September 11, 2025 – Field work and community engagement in American Samoa September 18, 2025 Photo & Video Chronology – August 28-September 11, 2025 – Field work and community engagement in American Samoa Photo and Video Chronology – American Samoa – August 2023 August 15, 2023 Photo and Video Chronology – American Samoa – August 2023 Volcano Watch — USGS Hawaiian Volcano Observatory staff return to American Samoa August 3, 2023 Volcano Watch — USGS Hawaiian Volcano Observatory staff return to American Samoa View All August 8, 2024 Volcanoes of American Samoa Volcanoes of American Samoa Upu Amata (Introduction) O le Atu-Samoa o le tasi lenei o faʻasologa motu mauga mu i le Vasa Pasefika i Saute. O motu e pito i sasaʻe o nei faʻasologa mauga mu o le Atu-Samoa, o motu ia o Amerika Samoa. E tofu lava mauga mu taʻitasi o Amerika Samoa ma ona talaaga aemaise tulaga e tutupu e ono pa ai i le lumanai. O loʻo galulue faʻatasi le Ofisa o le U.S. Geological Survey (USGS) ma le... Authors Natalia I. Deligne, Drew T. Downs, Elinor Lutu-McMoore, Steven Sobieszczyk, Wendy K. Stovall By Volcano Hazards Program Volcano Science Center Ofu-Olosega Ta'u Island Tutuila Island July 19, 2019 Volcanic hazards in the Pacific U.S. Territories 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... 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 October 22, 2018 2018 update to the U.S. Geological Survey national volcanic threat assessment 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... Authors John W. Ewert, Angela K. Diefenbach, David W. 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