MVO Says Volcano Activity Remains Low Following Recent Earthquakes

The Montserrat Volcano Observatory (MVO) has reported an increase in seismic activity at the Soufrière Hills Volcano during the week of May 8 to 15, driven largely by a felt earthquake and a subsequent swarm of volcano-tectonic events.

According to the MVO’s latest weekly report, activity at the volcano “remains low,” despite 59 volcano-tectonic (VT) earthquakes being recorded during the reporting period, significantly above last week’s total of 17 events and the four-week average of 19.

The report noted that the week’s activity included the earthquake felt across parts of Montserrat on the night of May 9.

“The seismic network recorded 59 volcano-tectonic earthquakes this week, including an event felt on Montserrat on 10 May at 01:02 UTC (21:02 ECT, 9 May) with a magnitude of 3.7,” the report stated.

The MVO had earlier revised the magnitude of the felt earthquake upward from an initial estimate of 2.7 to 3.7 following further analysis.

Scientists also recorded a notable earthquake swarm beginning on May 12.

The report stated that “38 events occurred in a swarm starting at 12:20 UTC on 12 May. This swarm lasted approximately 18 hours, with the largest event occurring at 13:23 UTC with a magnitude of 3.0.”

Despite the increased seismicity, the observatory stressed that volcanic activity remains within expected levels and the hazard level has not changed.

“The Hazard Level is 1,” the report confirmed.

The MVO continues to warn that the volcano remains capable of producing hazardous activity without warning due to the size of the lava dome.

“Due to the large size of the lava dome, pyroclastic flows can occur at any time without warning on any side of the volcano, including Gages from where they can travel rapidly into Plymouth,” the report warned.

Officials also cautioned residents and visitors about conditions in the Belham Valley.

“Tracks across the Belham Valley can be destroyed or heavily modified by flash flooding or lahars, and caution should be exercised crossing the valley during and after rainfall,” the report added.

Gas monitoring during the week showed sulphur dioxide flux averaging 154 tonnes per day, based on nine boat traverses conducted on May 8 and 13 helicopter traverses carried out on May 13.

Public access restrictions remain in effect. The MVO reminded the public that there is “no public access to Zone V, including Plymouth,” while Maritime Zones E and W remain open only for daytime transit between sunrise and sunset.

“Anyone who ignores these restrictions is liable to be prosecuted,” the report stated.

The weekly report was issued by Acting Director Karen Pascal.