Increased seismic activity at La Soufriere volcano

Residents of St Vincent and the Grenadines especially were warned to stay away from La Soufriere volcano due to increased seismic activity.

Prime Minister Ralph Gonsalves, urged the public to hope for the best even as the government plans for the worst as the volcano entered an effusive eruption stage.

“All the residents in the communities between Fancy to Georgetown and from North Leeward areas, from Belle Isle upwards, you have to be on alert, especially. At relatively short notice, you may get — MAY — an order to evacuate if, in fact, we have the scientific information that an explosive eruption will be occurring or at least the likelihood of it.”

An effusive eruption within the crater of La Soufriere, with visible gas and steam, was observed yesterday. As a result, the alert level has been elevated to Orange.

“This is what we call an effusive eruption going on at Soufriere, which essentially means magma is coming slowly out of the earth and building a dome,” said Professor Richard Robertson of the University of the West Indies Seismic Research Centre (SRC)

This means that there is highly elevated seismicity or fumarolic activity, or both, or other highly unusual symptoms. Eruptions may occur with less than 24 hours notice.

Experts said that the eruption is similar to what occurred in 1971/72, after which the volcano went dormant.

In a Facebook update, the University of the West Indies Seismic Research Centre (UWI-SRC) said that a small lava dome with fresh magma can be seen here as a black mound at the base of the existing dome in the crater at La Soufriere.

“Fresh magma has made a way to the surface of the crater without associated volcanic earthquakes typically found in the Lesser Antilles. This is an effusive eruption similar to what is seen in Hawaii however the lava is not as ‘runny’.”

Authorities said that monitoring systems are continuously manned and there is a regular visual inspection or potential vent areas as well as continuous ground deformation and hydrothermal monitoring.