Activity at the Soufrière Hills Volcano is low, although seismicity has increased.
The seismic network recorded nine rockfalls, one hundred and five volcano-tectonic (VT) and four hybrid earthquakes. Two swarms of VT earthquakes have occurred, one between 16:04 and 16:51 hrs on the 22 March with 49 events and another between 03:10 and 05:27 hrs on 23 March with 54 events. Earthquakes in the second swarm were markedly larger than those in the first.
The average sulphur dioxide measurement this week was 433 tonnes per day with a maximum of 654 and a minimum of 282 tonnes per day.
Observations on the morning of 23 March showed several changes on the volcano. Steam venting (Fumarolic) activity on the volcano has increased and a new steam vent (fumarole) has appeared on the northwest face of the lava dome behind Gages Mountain. A pulsing steam vent containing a small amount of ash has formed in the back of the February 2010 collapse scar. Very light ashfall is occurring on the western flank of the volcano. Audible roaring associated with the venting can be heard intermittently from MVO, 5.75 km NW of the volcano.
Pyroclastic flows can still occur at any time without warning. Lahars (mudflows) remain a hazard. Tracks across the Belham valley are frequently destroyed or heavily modified by lahars, therefore caution should be exercised crossing the valley during and after rainfall.
The Hazard Level is 2, however until further notice there will be no access to Zone C. Maritime zone W remains daytime transit only (boats may sail through the zone but must not stop).