The period of elevated volcano-tectonic (VT) earthquakes that began on Tuesday at La Soufriere stopped on Friday, National Emergency Management Organisation (NEMO) said on Saturday in its daily bulletin.
“Since then, the only seismic activity being recorded is small low frequency events associated with the growth of the dome.”
NEMO said that these kinds of events were dominant before Tuesday.
“Their rate of occurrence does not appear to have changed as a result of the volcano tectonic earthquake swarm.”
On Wednesday, Director of NEMO, Michelle Forbes said that persons close to the volcano should be prepared to evacuate at short notice.
“We have been saying for the last few months we have to be ready for any sudden change, any quick change,” Forbes said on VC3’s Roundtable Talk.
Speaking on the same programme, geologist Professor Richard Robertson, who heads the volcano monitoring team, endorsed Forbe’s comments.
Robertson said that the country has been fortunate this time, in that, unlike 1979, when the volcano last erupted, the current eruption began effusively.
“And for the last three months, it’s been erupting quietly. So people talk about warning of an explosive eruption, the warning you are getting now is your warning. So if you didn’t know in December that this volcano could erupt, you should have known by January, you should have known by February, and you certainly should have known by March,” Robertson said.
“And just in case you didn’t know, the volcano now starts to give you events that are felt and you can actually feel that something is happening,” he said, referring to the volcano earthquakes felt earlier this week.
He said that there is observable burning of the vegetation on the dome of the volcano and earthquakes were being felt.
“I don’t know, people, what other warning you can get that this volcano is erupting; that it can do some nasty things,” Robertson told VC3.
He said that people should not panic but should ensure that they have plans in place.
“You have to have plans if you live in the red and orange zones and there is lots of information that NEMO has put out in terms of what you should do. You should have plans that just in case you have to move south, you know what you are going to do and not wait until it actually happens to put the plan in place or, I dare say, expect that somebody else is going to do it for you.
“This volcano is giving you plenty warning; I suggest you take the warning,” Robertson said.
New dome doubles in size
And, in its bulletin on Saturday, NEMO said that the new dome continues to grow towards the Leeward And Windward Sides Of The Volcano with the most active gas emissions being at the top of the new dome, as well as the contact areas between the pre-existing 1979 and 2020/21 dome.
A drone survey of the dome conducted on March 19 indicates that approximately 6,291,084 cubic metres of new material (nearly double in size), has been added to the dome since the last survey on Feb. 12.
Measurements of carbon dioxide in the soil were conducted on the lower windward sides of the volcano and fieldwork was carried out in the lower parts of the Wallibou river on Saturday.
Technicians at the Soufriere Monitoring Unit successfully repaired the seismic station at Fancy on Friday.
This station is once again streaming data into the monitoring network.
The alert level remains at orange, the third highest on the four-level scale, with red being the highest.
The orange alert means there is a highly elevated level of seismicity or fumarolic activity or both and that eruptions may occur with less than 24 hours’ notice.
NEMO is reminding the public that no evacuation order or notice has been issued and continues to appeal to the public to desist from visiting the volcano, especially going into the crater, since doing so is extremely dangerous.