Volcano Watch: HVO responds to American Samoa earthquake reports

  • USGS graphic This reference map depicts the volcanic islands of American Samoa, and specifically the Manu‘a Islands of Ofu, Olosega, and Ta‘u. 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. Two seismometers (black squares on map) have thus far been deployed on Ta‘u and Olosega, the data from which suggest that the earthquakes are occurring in the vicinity of Ta‘u. The last volcanic eruption in this area was a submarine eruption in 1866 (approximate location indicated by dashed circle). Another volcano, Vailuluu‘u, sits 25 miles (40 kilometers) east of Ta‘u and 2,000 feet (600 meters) below sea level; it has erupted as recently as 2003. Tutuila Island, the main population center of American Samoa, is approximately 60 miles (100 kilometers) west of the Manu‘a Islands.

Earthquakes have been felt since late July in the Manu‘a Islands of American Samoa in the South Pacific. These earthquakes are likely associated with magmatic activity beneath the islands. The USGS Hawaiian Volcano Observatory is working closely with federal partners, American Samoan officials, and local residents to better understand the source and potential hazard implications of these ongoing earthquakes.