La Soufriere Eruption Scientific Update
Following the gradual decline of near-continuous seismic tremor at La Soufrière, St Vincent, the seismic network started to record banded tremor from about 3:30 am onwards on 10 April.
Banded tremor is a seismic signal which indicates that fluid (magma and gas) are approaching the surface
Each tremor episode lasted 20 to 30 minutes, with gaps between them of one to three hours. The episodes appeared to coincide with periods of enhanced venting or explosive activity.
The background level of seismic tremor between the episodes continued to decline.
Ash thickness from the past 24 hours of eruptive activity varied from <1mm in Colonaire (~12.5 km from the volcano) to 10-15mm in Rabacca (~7.4 k from the volcano).
Ash thickness and grain size generally increased from Kingstown northwards to the volcano. Ashfall was reported in parts of Barbados and Saint Lucia.
The volcano has entered an explosive eruptive phase that may continue over the next few days and weeks. Explosions are expected to be of similar or larger magnitude.
