On December 27th 2020, the first eruption at the Soufriere Saint Vincent volcano in
41 years began.
Initially, this eruption was not very destructive, and built a feature known as a lava dome.
Over subsequent months, this dome continued to expand at a very slow rate.
Then, on April 8th, 2021 scientists noted a new type of volcanic tremor at the volcano.
This indicates that additional magma is moving towards the surface.
As a result, scientists including myself expect an imminent explosive eruption to begin at
La Soufriere volcano with very little notice, perhaps within 48 hours.
As of 18:30 local time on the island, mandatory evacuations have been issued across the volcano's
red zone which I have marked on screen.
If you live in this area, PLEASE evacuate.
La Soufriere is one of the most dangerous volcanoes in the Caribbean, and it caused
more than a thousand casualties when it erupted in 1902.
I do not want a repeat of that horrible eruption.
Homes can be replaced but people cannot.
Before I state what I expect to occur in the next few weeks, let me summarize what has
happened so far since the eruption began.
La Soufriere is the northernmost volcano on the island of Saint Vincent, and is the only
volcano which is still considered to be active.
Unlike Kilauea in Hawaii, La Soufriere is a stratovolcano.
Stratovolcanoes are built out of alternating layers of both lava and ash, and tend to have
relatively steep slopes.
The eruption which began on December 27th started to build a dome of dark colored lava.
The reason why the lava formed a dome instead of quickly flowing downhill like you see from
the current eruption in Iceland is due to the high viscosity of the lava.
The lava which has been erupting has 55.3% silicon dioxide by weight, which means it
can be classified as basaltic andesite.
As such, the lava dome continued to expand at a rate of about 11 meters each day.
By February 1st, the lava dome measured 93 meters tall, 231 meters wide and 511 meters
long.
By March 19th this lava dome had further expanded to nearly a kilometer in length, and had nearly
tripled in terms of overall volume.
Then, on April 5th, a series of moderate magnitude earthquake occurred beneath the volcano, hinting
at additional lava moving towards the surface.
These earthquakes then increased in number and frequency on April 7th, and became nearly
constant in what scientists call a harmonic tremor.
So, why are scientists ordering an evacuation?
Simple.
All lavas produce various gasses such as sulfur dioxide and carbon dioxide.
Normally, this gas would largely escape into the atmosphere.
However, currently there is a massive lava dome blocking the path of this new gas.
As a result, the combustible gasses will continue to build in volume AND pressure beneath the
dome until it reaches a critical point and violently explodes outwards.
As such, I expect the following cycle to occur over the next few weeks.
First, a violent explosion takes place in what is termed a "sub-plinian" eruption.
After a large explosion, a tall column of ash will shoot into the sky and rain down
hot ashes across a vast section of the island.
Pyroclastic flows are also very likely to form at the same time, and can theoretically
travel in any direction.
These flows destroy everything in their path, so potential areas where they could travel
must be cleared of people.
Next, viscous lava will build to fill the hole created by the explosion.
Pressure will then once again build, causing a repeat in the cycle.
With all of this being said, it is still quite possible that La Soufriere will not explosively
erupt.
If it does erupt explosively, it may be relatively underwhelming.
I personally am hoping for this scenario, as with volcanoes we assume the worst but
hope for the best.
In the video description I have linked to several more official sources which will provide
24/7 updates on this volcanic eruption.
I hope that you enjoyed this video.
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