LA SOUFRIÈRE BULLETIN #75 APRIL 22, 2021 6:00 PM
Seismic activity at La Soufrière Volcano continued the pattern established after the explosive activity on 18 April.
Small long-period and hybrid earthquakes continued to be recorded, with their rate of occurrence gradually increasing.
High-level seismic tremor started at 11:09 am, generated by explosive activity, and lasted for about 20 minutes.
A vertical explosive eruption plume rose slowly above the crater eventually reaching a height of about 8 km. During the initial stages of the explosion, a base surge (pyroclastic density current) was seen moving down the western flank of the volcano. Tremor continued, at a lower level, for the next two hours as La Soufrière continued to vent ash.
Since the initial depressurization noted immediately following the April 9 explosive phase, the continuous GPS network has recorded a decrease in the overall rates of horizontal and vertical movement.
The volcano continues to erupt. Its pattern of seismic activity over the last few days is typical of the growth and destruction of lava domes. Explosions with accompanying ashfall, of similar or larger magnitude, can occur with little or no warning.
