By: Staff Writer
January 1, 2021
A top Caribbean volcanologist said that the La Soufriere volcano in St Vincent (SVG) can become explosive in 48 hours or less, urges people not to visit the volcano site at any time during this active period.
The La Soufriere volcano is active and it is at an effusive stage where the magma and lava is just oozing out of the crater, however this may change in 48 hours or less and the volcano can become explosive, leaving citizens with a little under two days to evacuate if it comes to that.
Dr Richard Robertson, professor of geology and past director of the University of the West Indies Seismic Research Centre (UWISRC), speaking at a video conference on Tuesday to SVG prime minister, Dr Ralph Gonsalves and the media, said: “we try to understand natural systems as best as we can, which I think we can keep a close eye on, of course, [things] can happen faster. But we are trying to make sure that we could keep a close eye on it [and] we would hope that 48 hours before that something is going to happen.”
“Of course, once your people are educated in what to do, you can move fast. There are certain specific risks related to an explosive eruption that the people at NEMO (National Emergency Management Organisation) are aware of in terms of logistics of moving from A to B like that.”
“But really, we’re trying to make sure you have whatever time you need, that you need to move people out of harms way, we want to make sure you have that time to do it, whether it is 48 hours or 24 hours, whatever time that is, we want to be in a position to give you that. We will try as hard as we can to do that.”
The last time the La Soufriere volcano erupted was on April 13, 1979 after 10 months of mild premonitory activity. A series of strong vertical explosions between April 13 to April 26 generated ash falls, pyroclastic flows and mudflows. From approximately May 3 onwards basaltic–andesite lava has been accumulating in the summit crater.
There was volcanic activity recorded from November of this year surrounding La Soufriere, however Dr Robertson said that the reason why the government of SVG was not alerted earlier is because there has always been moderate seismic activity coming from around the region and the levels of activity seen from the La Soufriere was not significant enough to warrant any special attention.
Dr. Erouscilla Patricia Joseph, director of the UWISRC, said: “The maximum number of earthquakes on any day that were recorded by the network was eight, eight events. So that is within such a very, very low level of seismicity that it wasn’t within an extremely unusual range.”
“It was unusual enough for us to advise NEMO however, it was not with like we went from zero to hundreds or 10’s of earthquakes.”
The last time La Soufriere had an effusive eruption was in 1971 where magma oozed from the crater, but an explosive eruption did not occur. It was just after a period of time the oozing stopped and the volcano activity ceased.
Dr Joseph also said: “We are already in the phase of extrusion. So at this point in time, if we start to see any increase in activity, it’s related to seismic activity, it’s related to changes in the system. So any significant increase would continue to be looked at as a sign of form a rapid changes in the system.”
Dr Robertson added: “In volcanoes prior to eruptions, the number of events you can get could go up to hundreds and 1000’s per day. They’re really ramping up. So I mean, if in an explosive phase of Soufriere in 1979 we had hundreds and hundreds of events per day, 1000s of events per day. In Montserrat, we went over that regularly.”
The last major volcanic eruption that caused significant damage in the region happened July 18, 1995 in Montserrat when the previously dormant Soufriere Hills volcano, in the southern part of the island, became active. Eruptions destroyed Montserrat’s Georgian era capital city of Plymouth. Between 1995 and 2000, two-thirds of the island’s population was forced to flee, primarily to the United Kingdom, leaving fewer than 1,200 people on the island in 1997 (rising to nearly 5000 by 2016)
Dr Ralph Gonsalves, prime minister of SVG, said that at the moment the state of alert will be elevated to orange from yellow, but is reminding residents that this is just an alert and not an evacuation notice. But in the event that there needs to be an evacuation notice the public will be made aware and steps will be taken from their national emergency plan, inclusive of transportation of persons form hot zones as well as proper evacuation protocols taken to ensure the safety of residents during the evacuation process.
Teams from the UWISRC had arrived in SVG last week week to conduct more tests on the rocks and seismic activity of the Soufriere mount to make better determinations on what could happen with the volcano within the oncoming days and weeks.
In the meantime, Dr Robertson urges people to resist the temptation of going near the volcano or its crater, citing the extreme danger the rocks and the lava can present to persons.
The UWISRC updated their Facebook page with new images of the volcano, which shows a small lava dome with fresh magma can be seen as a black mound at the base of the existing dome in the crater at the La Soufriere volcano.