Images

Early morning photo of the three islands that make up the Manuʻa Islands in American Samoa. Ofu Island is in the foreground, Olosega Island in the middle ground, and Taʻū Island is in the background. Ofu-Olosega islands and Taʻū Island are the tops of volcanoes, most of which are under the ocean surface. USGS photo by D. Downs.

A view of the southeast side of Olosega Island (foreground), with Ofu Island visible in the background. These volcanoes have steep cliffs and are separated by a 50-foot (15 meter) channel. The steep cliff in the photo is a dike sticking out into the ocean that has been more resistant to weathering than surrounding lava flows. USGS photo by D. Downs.

This reference map depicts the volcanoes in the Manuʻa Islands, American Samoa, the site of seismic unrest between July and September 2022. Marked on the map are the locations of Hawaiian Volcano Observatory GPS and seismometers in the islands.

Map of the American Samoa volcano-monitoring network (top). Data from Wake Island hydrograph (located about 4,500 km, or 2,900 miles, northwest of Taʻū Island) shows the general trend in the number of events during the 2022 earthquake swarm (bottom left). Locations for larger earthquakes (M2.5 and greater) are available starting August 20, 2022 (bottom right).

Bathymetric data from the National Oceanic and Atmospheric Administration (NOAA) collected around American Samoa. Light gray areas are the islands of Tutuila, Ofu-Olosega, and Taʻū. Black lines are 1,640 ft (500 m) contour intervals below sea level.

This reference map depicts the topography and bathymetry of the volcanoes in the Manu‘a Islands, American Samoa. The highest elevation in the area is Lata Mountain on Ta‘ū Island, standing 3,179 feet (969 meters) above sea level.

An afternoon view of the tuff cone near Faleāsao village located in northwest Ta‘ū island, with the islands of Ofu and Olosega visible in the distance. This tuff cone, which is thousands of years old, formed when hot magma interacted with either shallow groundwater or sea water. There are several tuff cones located within the northwest corner of Ta‘ū island.

NOAA Ofu and Olosega multibeam bathymetry and IKONOS derived depths. Location of the 1866 eruption is annotated. 

This reference map depicts the volcanic islands of American Samoa, and specifically the Manu‘a Islands of Ofu, Olosega, and Ta‘ū. In recent days and weeks, residents of the islands have been feeling moderate earthquakes, and the Hawaiian Volcano Observatory has deployed several staff members to American Samoa to help monitor the unrest.

View of south part of western side of Nuʻutele Island, off the west coast of Ofu Island in the Manuʻa Islands, American Samoa. Nuʻutele Island is an eroded tuff cone of Ofu-Olosega volcano. A tuff cone can form when magma and water interact at shallow depths, causing localized explosions.

NASA Astronaut image of Ofu-Olosega islands (Manu'a Islands, American Samoa) in the South Pacific Ocean. NASA Space Shuttle image ISS002-E-6878 (https://eol.jsc.nasa.gov/SearchPhotos/photo.pl?mission=ISS002&roll=E&fr…).