MVO Weekly Report for the Period 13 to 20 October 2023

Activity at the Soufrière Hills Volcano remains low.

The seismic network recorded eight volcano tectonic earthquakes and three rockfalls this week.

Measurements of the SO2 flux were taken by helicopter on 18 October. There were ten traverses with an average flux of 191 tonnes per day.

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. 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 Hazard Level is 1. There is no public access to Zone V, including Plymouth. Maritime Zones E and W are daytime transit only between sunrise and sunset (boats may sail through the zone but must not stop). Anyone who ignores these restrictions is liable to be prosecuted.

This report along with additional information on the Soufrière Hills Volcano and the Hazard Level System can be found at the MVO website: Old weekly reports can be downloaded from You can also follow @mvoms on both Facebook, Instagram, and Twitter.


Graham A. Ryan