Images

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.

Broadband seismometer site on eastern Taʻū, American Samoa, before (inset) and after a work party cleared rapidly growing vegetation which had covered the solar panels along with the boulders to the right of the main photo. Due to lack of power from the solar panels being unable to charge during the day, the station was offline for many months.

USGS Hawaiian Volcano Observatory scientists and NOAA National Weather Service Weather Service Office Pago Pago meteorologists travelled by boat between the Manuʻa Islands, American Samoa, during an outreach and monitoring network maintenance trip in early September 2025. This view is from the boat looking south towards the north side of Ofu Island.

Photo of the USGS Global Positioning System (GPS) monitoring station on western Ta‘ū Island in the Manuʻa Islands of American Samoa. The station consists of a GPS unit, which can measure very slight movements of the ground, placed on a tripod that is leveled and centered over a benchmark.

This photo shows part of the western Ofu coastline and several small islands west of Ofu Island, American Samoa. These islands are considered part of Ofu-Olosega volcano in the Manuʻa Islands.

USGS Hawaiian Volcano Observatory scientists took this photo of Aunu‘u Island while on a flight from Tutuila to Ofu Island in American Samoa on September 2, 2025. The view is from the south looking north. Aunu‘u Island is a tuff cone less than 1 mile southeast of Tutuila Island and is considered part of Tutuila volcano.

USGS Hawaiian Volcano Observatory chief field engineer Kevan Kamibayashi conducts maintenance on a volcano-monitoring station located in American Samoa. USGS photo by J. Chang. 

Photograph of the Colorado River in the Grand Canyon, Arizona, USA. Photo taken on September 8, 2023.

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).

A USGS scientist installs a seismic station on Tutuila island in American Samoa. This station joins several other stations recently installed in the Manu‘a Islands to monitor activity in American Samoa. USGS photo by A. Ellis.

On the northwest coast of Ta‘ū Island (near Faleāsao village), half of a tuff cone, which is likely thousands of years old, is visible. Ocean waves have eroded away the other half of the tuff cone, which formed when hot magma interacted with either shallow groundwater or sea water. USGS image by J. Chang.

The tuff cone on the northwest coast of Ta‘ū Island (near Faleāsao village) is mostly composed of fine-grained ash with larger lithic clasts (fragments of older rock material). Some of these lithic clasts are larger than 1 meter or 3 feet in diameter and are scattered throughout the tuff cone. USGS image by J. Chang.

USGS staff are on Ta‘ū Island in American Samoa to begin installing Global Positioning System (GPS) receiver monitoring sites. GPS equipment is able to detect very slight movements of the ground and will help the USGS to better understand what is happening beneath the ground and provide more accurate hazard assessments. USGS image by J. Chang.

Photograph of a Global Positioning System (GPS) station on Ta‘ū Island in American Samoa. Solar panels and batteries in a weather-proof enclosure power the station, which consists of a GPS unit placed on a tripod that is leveled and centered over a benchmark.

Wake Island is about 2,800 miles (4,500 km) northwest of Ta'ū volcano in American Samoa. Both are located in the Pacific Ocean. 

This reference map depicts the topography and bathymetry of the volcanoes in the Manu‘a Islands, American Samoa, where seismic unrest has been ongoing for several weeks. The highest elevation in the area is Lata Mountain on Ta‘ū Island, standing 3,179 feet (969 meters) above 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.

A USGS Hawaiian Volcano Observatory geologist collects a rock sample using a rock hammer on Ta‘ū Island, American Samoa. HVO staff are in American Samoa responding to earthquake activity. While there to install monitoring instrumentation, they are also collecting rock samples to better understand past volcanic activity in American Samoa. USGS image by J. Chang.

A USGS Hawaiian Volcano Observatory geologist collects a sample of a pāhoehoe lava flow above a thick ‘a‘ā lava flow on Ta‘ū Island, American Samoa. At that location, samples of a sequence of alternating pāhoehoe and ‘a‘ā lava flows were sampled to help reconstruct the eruptive history of Ta‘ū volcano.