By Fili Sagapolutele in Pago Pago
Following a swarm of earthquakes detected at the Manu'a Island Group in American Samoa, the US Geological Survey has dispatched a team to Pago Pago to assess and set up equipment to monitor seismic activities in the island group.
Pago Pago. Photo: 123rf
Leading the team is Dr Natalia Deligne of the US Geological Survey Hawaiian Volcano Observatory (HVO), who arrived in Pago Pago on 11 August and is consulting with territorial authorities.
The American Samoa government operated a charter flight over the weekend taking the federal team along with territorial government officials to the islands of Ta'u and Ofu for the assessments and outreach as well as to set up seismic equipment.
Additional HVO personnel and earthquake detection instruments are expected to arrive in American Samoa next week, along with Dr Charles McCreery, director of the Hawaii-based Pacific Tsunami Warning Center.
A USGS summary report Friday stated that residents of the Manuʻa island group continue to feel earthquakes.
Reports from National Park of American Samoa staff and Taʻu island residents suggest that the activity began on 26 July.
Since 10 August, earthquakes have also been reported by residents of Ofu and Olosega islands.
Reports suggest that the earthquakes vary in intensity, but are generally short, sharp jolts.
The earthquakes are more likely to be felt by people indoors at rest and along the coast, where buildings sit on sediment that amplifies shaking.
According to USGS, these earthquakes are most likely related to either Taʻu volcano or the nearby submarine Vailuluʻu volcano.
Several residents of Taʻu island reported loud booming noises on the night of 10 August, and no other noises have been reported since then.
Experts at the Pago Pago National Weather Service Office, USGS Volcano Hazards Program, NOAA Pacific Tsunami Warning Center and NOAA-IOC International Tsunami Information Center and USGS National Earthquake Information Center said they are working together with the American Samoa government to understand the source of these earthquakes better.
The Samoa Meteorological Service in Apia is also reporting increased seismic activity south of American Samoa's main island of Tutuila.
American Samoa's volcanoes are monitored remotely by satellites and a seismic station in Apia, Samoa.
These instruments might detect significant explosive activity in American Samoa, but the lack of ground-based monitoring stations at the volcanoes does not allow for advanced warning of new activity.