Significant ashfall at Argyle International Airport, St. Vincent following multiple explosive eruptions of the La Soufrière Volcano.
|Present La Soufrière Alert Level:||ORANGE||There is a highly elevated level of seismic and/or fumarolic activity or other unusual activity. An eruption may begin with less than twenty-four hours’ notice.|
The University of the West Indies Seismic Research Centre (UWI SRC), in their scientific advisory issued at 6:00 PM Saturday 10th April 2021, stated that ashfall from La Soufrière was reported in parts of Barbados and Saint Lucia.
Within St. Vincent and the Grenadines, 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 km from the volcano).
The UWI SRC also stated 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.
Seismic activity continues across St. Vincent. Following the gradual decline of near-continuous seismic tremors at La Soufrière, St Vincent, the seismic network started to record banded tremors from about 3:30 AM onwards on 10 April.
A 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. However, the background level of seismic tremors between the episodes continued to decline.