SHARLENE RAMPERSAD
Twenty four hours before the La Soufriere volcano in St Vincent and the Grenadines began to explosively erupt on April 9, residents in the volcano’s red and orange zones were told to evacuate.
This was possible because the volcano’s activity was being closely monitored by the University of the West Indies (UWI’s) Seismic Research Centre (SRC.)
In a virtual media conference yesterday, UWI’s SRC gave an update on the volcano’s activity.
Professor Richard Roberston said while La Soufriere’s pattern of activity has changed since the first eruption, explosive activity may continue.
“We would expect as we continue for this type of activity to continue like this, so you may have discrete explosions, they may be of a similar kind of order like we’ve had in the past or they may be smaller and then we might have discrete periods when its quiet. Our interpretation of all of this is that the volcano is really trying to get rid of all the gas that came up in the pulse that started all this going and as it get rids of the gas, there is a possibility that it would then reform a dome,” Robertson said.
He said if a dome is reformed, it may help in stopping the explosions that have been happening.
Robertson said the volcano may go back to sleep once the current batch of magma has run its course. But predicting the activity of the volcano is not an exact science.
“It is possible that that might be the end of it, the volcano goes back to sleep for N number of years, but it is also possible that another batch of gas rich magma may come along and essentially the process going again where we have a very intense period and then it getting into more discrete events and possibly the formation of a dome.”
Robertson said in the early part of the eruptions, the explosions were very intense and produced a lot of ash.
“There was a lot of ash that went into the atmosphere and went into the air and because it went on for a few hours or a few days more or less, continuously, not really stopping fully in terms of the ash venting, there was a lot of ash dumped in St Vincent and the Grenadines and also in Barbados and in some cases in St Lucia.”
He said the explosions and venting became less continuous and more discrete, leaving large gaps between eruptions.
“That period of intense activity became more discrete as the days went on from Friday when we had the first explosion to Sunday, Monday, we began to see some gaps in terms of spacing of the explosions. So the explosions and the venting became less continuous and more discrete and as we continued, the gaps between the explosive eruptions were lengthened and we began to see evidence that you had magma moving through the VTs and long period events.”
He said the UWI SRC has a monitoring system in place that can detect if there is a new invigoration of material in the volcano. He said this places them in a good position to inform the people of St Vincent and the Grenadines if the volcano is erupting again, to ensure they stay safely away from the volcano.