Activity at the Soufrière Hills Volcano remains low.
The seismic network recorded 18 volcano-tectonic earthquakes this week. 13 of these occurred in a very brief swarm which started at about 04:42 (local time) on 5th March.
Sulphur-dioxide measurements were not possible during the reporting period.
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 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.
The complex, dominantly andesitic Soufrière Hills volcano occupies the southern half of the island of Montserrat. The summit area consists primarily of a series of lava domes emplaced along an ESE-trending zone. The volcano is flanked to Pleistocene complexes to the north and south. English’s Crater, a 1-km-wide crater breached widely to the east by edifice collapse, was formed about 2000 years ago as a result of the youngest of several collapse events producing submarine debris-avalanche deposits. Block-and-ash flow and surge deposits associated with dome growth predominate in flank deposits, including those from an eruption that likely preceded the 1632 AD settlement of the island, allowing cultivation on recently devegetated land to near the summit of the volcano. Non-eruptive seismic swarms occurred at 30-year intervals in the 20th century, but no historical eruptions were recorded on Montserrat until 1995. Long-term small-to-moderate ash eruptions beginning in that year were later accompanied by lava-dome growth and pyroclastic flows that forced evacuation of the southern half of the island and ultimately destroyed the capital city of Plymouth, causing major social and economic disruption.
March 16, 2016. Soufrière Hills , Montserrat :
Source : MVO , GVP.
Photos : Photovolcanica ( 2010 ),