Activity at the Soufrière Hills Volcano is low, although seismicity remains slightly elevated.
The seismic network recorded twenty VT earthquakes, four hybrid events, four long-period events and fourteen rockfalls this week. Most of these events occurred on 11 September, however it should be noted that all of these events are small.
Sulphur dioxide measurements on five days this week gave an average output of 341 tonnes per day, with a maximum of 651 and a minimum of 234.
Some clear views of the dome this week showed continued instability of the steep eastern face of the dome. Rockfall activity is undercutting the vertical face and it is overhanging in places. Further rockfall and pyroclastic flow activity is likely in the coming days and weeks.
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. Tracks across the Belham valley are frequently destroyed or heavily modified by flash flooding or lahars, and caution should be exercised crossing the valley during and after rainfall.
The Hazard Level is 2. There is no access to Plymouth or Zone V. There is daytime access (8:00 am to 4:00 pm) to Zone C. Maritime zone W remains daytime transit only (boats may sail through the zone but must not stop).