Images

On the left is a map with an upper inset showing the location of American Samoa in the South Pacific Ocean, a lower inset showing the overall volcano monitoring network of the territory, and the main map showing the topography and bathymetry of the Manua Islands along with the current monitoring network (unchanged since September 2025).

This photo, taken from an airplane, shows Ofu Island from the south looking north. Nuʻutele Island is visible to the left (west) of Ofu Island. The tallest point of Ofu Island is the peak of Tumutumu Mountain at 1,611 feet (491 meters). The westernmost edge of Olosega Island is visible to the right of Ofu Island; the two islands are connected by the Asaga bridge.

This photo, taken from an airplane, shows Ofu-Olosega from the southeast looking northwest. Olosega Island is in the right foreground, while Ofu Island is in the middle left background. Ocean waves are breaking at some distance from shore where there is a coral reef. According to the 2020 US Census, less than 300 people live on Ofu-Olosega. USGS photo by N.

This photo, taken from a boat looking to the northwest, shows Olosega Island on the right and Ofu Island on the left in the distance. Together, they make up the top of Ofu-Olosega volcano, most of which is underwater. USGS photo by N. Deligne.

This photo, taken from a boat, shows the northwest side of Nuʻutele Island, off the west coast of Ofu Island in the Manuʻa Islands, American Samoa. Nuʻutele Island, which may be known by other names locally, 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.

This photo, taken from a boat looking south, shows Olosega Island to the left, Ofu Island to the right, and the Asaga bridge connecting the two islands. The Asaga bridge was built in 1970; this single-lane bridge connects the two islands that form Ofu-Olosega volcano. USGS photo by N. Deligne.

This photo, taken from a boat, shows the eastern side of Olosega Island in the Manuʻa Islands of American Samoa. This volcanic island is part of Ofu-Olosega volcano, which is estimated to be 440,000 years old. USGS photo by N. Deligne.

This reference map depicts the volcanoes of the Manuʻa Islands, American Samoa, which are monitored by the USGS Hawaiian Volcano Observatory.

This photo, taken from a boat, shows Olosega Island on the left, and Ofu Island further away on the right, in the Manuʻs Islands of American Samoa. These islands, connected by a one-lane bridge (out of sight), are the top of Ofu-Olosega volcano. USGS photo by N. Deligne.

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.

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.

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

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…).