Updated: September 24, 2022
Ofu-Olosega Islands volcano has been ruled out as the source of the ongoing Manuʻa Islands earthquake swarm, according to volcano notice issued by the USGS’ Hawaiian Volcano Observatory.
Data from seismometers installed in the Manuʻa Islands in American Samoa this week confirms that the ongoing earthquake activity is related to Taʻū Island volcano and not Ofu-Olosega.
Accordingly, the USGS is lowering the volcano alert level to NORMAL and the aviation color code to GREEN for Ofu-Olosega. Taʻū Island remains at ADVISORY/YELLOW.
“Due to the closeness of the Ofu-Olosega Islands to Taʻū Island, residents of Ofu-Olosega could still be significantly affected by events that may take place on or around Taʻu Island. The earthquake swarm is still ongoing, and people on Ofu-Olosega are likely to feel shaking from future events,” according to the notice.
Residents of Ofu-Olosega can now find updates on relevant hazards and other important information in the Daily Reports for Taʻū Island. The USGS advises that possible hazards that could impact residents of Ofu-Olosega include “shaking related to strong, damaging earthquakes, local tsunamis or large waves related to underwater volcanic activity or landslides, and/or ash and gas from volcanic eruptions.”
USGS scientists continue to monitor the earthquake swarm with six microseismometers placed on Tutuila, Taʻū, and Olosega Islands and two more sensitive seismometers on Taʻū and Ofu Islands. The USGS is working to bring a third advanced seismometer online on eastern Ta’u Island.
Residents can assist USGS and NWS monitoring efforts by noting and reporting accurate times when they feel earthquake shaking or notice other changes that might be related to volcanic activity to either the NOAA Pago Pago National Weather Service Office (https://www.weather.gov/ppg/wsopagooffice) or the American Samoa EOC in Pago Pago (684-699-3800).