There has been no significant change to the earthquake activity beneath or around Ta’ū and Ofu-Olosega Islands since yesterday’s update and that larger, more sophisticated, and accurate seismometers are being installed in the coming week.
The US Geological Survey staff have identified sites on Taʻū Island where advanced seismometers will be installed in the coming days. On August 20, USGS staff gave a briefing to the Governor, Lieutenant Governor, members of the cabinet, and other officials at the Governor’s Special Meeting.
The USGS briefing covered USGS information products, alert level and aviation color codes, scenarios, and hazards.
Over the past several days approximately 20 earthquakes per hour have been recorded. Though the exact count isn’t available, the number of recorded earthquakes in the past 24 hours appears slightly lower. The estimated size of the largest earthquakes is between magnitude 2 and 3.
Preliminary estimates place the earthquake source closer to Ta’u Island than Ofo-Olosega. Reports of booming sounds on August 20 and the morning of 21 are being investigated.
USGS scientists are monitoring the earthquakes with microseismometers (small and basic earthquake detectors) placed on Tutuila, Taʻū, and Ofu-Olosega Islands.
Larger, more sophisticated, and accurate seismometers are being installed in the coming week. Data from the new equipment will help to accurately locate the earthquakes and develop better assessments of possible future hazards.