The eruption of the La Soufrière volcano is the largest in more than a century in Saint Vincent "and it is not over yet"

Soldiers and residents of San Vicente on a street in Kingstown, the capital, covered in ash by the eruption of the La Soufrière volcano on April 10.Orvil Samuel / AP

Professor Richard Robertson became a geologist because of his interest in the eruption of the La Soufrière volcano, in his native San Vicente, in 1979. 42 years later, he is the man who informs the citizens of this southern island every day of the Caribbean from the activity of that mountain, which began to emit columns of smoke and ash on April 9 after a period of inactivity of more than four decades.

From the observatory in San Vicente of the Center for Seismic Research of the University of the West Indies in Trinidad and Tobago (UWI, for its acronym in English), Robertson tells the population of explosive events accompanied by tremors followed by periods of calm what La Soufrière has experienced in the last two weeks and the preventive measures they should take after the eruption. So far, 16,000 people have been evacuated. The emitted ash has turned the island's lush vegetation gray, caused cuts in basic services and has even reached neighboring Barbados, the Grenadines and Saint Lucia. And the United Nations has launched a request for funds of $ 29.2 million to help those affected by the eruption in Saint Vincent and the Grenadines and other affected countries.

"As a specialist in volcanoes, you study them and you want to see them erupt, but it generates a contradiction because you don't want to see the harmful effects it has," explains Robertson in an interview with EL PAÍS.

In this case, the geologist says he is proud because, thanks to scientific evidence, they were able to warn the population to evacuate the area before the eruption and for the moment there have been no fatalities to mourn.

More information

• Saint Vincent, covered in ash by the explosion of the La Soufrière volcano

• La Soufrière volcano activity suffocates Saint Vincent

However, the eruption is not over.

As he warns, it could last for months and, although it is still too early to count the damage, he considers that the magnitude of this eruption will be greater than that of 1979 and more similar than that of 1902, when a similar event devastated the communities that lived in the region. sugar industry on the mountainside and more than 1,000 people lost their lives more than a century ago.

The key this time so that it is not being fatal, he assures, is in prevention.

“You have to have plans and processes to deal with the dangers of the volcano.

We cannot ignore them.

We have to monitor it and make sure that we understand its activity to implement the plans.

If we do, we can live with its majesty ”.

Question.

What is the situation of the volcano at the moment?

Answer.

Right now the volcano has entered a phase characterized by long periods of inactivity and hybrid earthquakes.

The last explosion was on April 18 of this month and that one, which started very intense, seems to have ended and we have entered a period of activity in which you have intense tremors associated with the eruption but without explosions.

However, we believe there will be more explosions in the future.

The operation is as follows: there is an explosion, a space without activity, more explosions and then a new inactive space.

That is what happened.

Right now we are in a period without them, but we would not be surprised if the explosions return in the short term.

Q.

What is the difference between the previous eruption of the volcano, in 1979, and this one?

R.

It was similar and different; similar because it was also an explosive event. The two began with eruptions of the volcano. But, in the eruption of 79 the explosions were not as dynamic and vigorous as in this case. This time, it started with an explosion [on April 9] and followed with another at the end of the day and one more the next day. From Friday [which erupted] to Sunday morning, there were explosions and it emitted gushing ash. That intense spirit is what sets it apart from the 1979 eruption. Then there were not these very intense periods of ash emission and outbursts, but a great explosive period of about two weeks. We believe that this time, in terms of the material that is emitting and the explosiveness that has pulverized the volcanic material, this eruption is larger than the one in 1979 and is not over yet.We think that when it does, the dimension will probably be more similar to the 1902 eruption which was about ten times larger than the 1979 one. It is not over yet, so we don't know yet how much larger.

A man looks at the panorama from the balcony of his house after the eruption of the La Soufrière volcano in Saint Vincent, on April 18, 2021.ROBERTSON S. HENRY / Reuters

Q.

As you say, the volcano is still active, but it has been more than two weeks since La Soufrière erupted.

Can a preliminary damage count be done?

How is it affecting the population?

R.

The beginning of this eruption was very intense. And because the explosions were so dynamic and powerful, they generated a lot of ash, which is basically these fragmented rock particles from the lava coming out of the volcano. And because they were propelled so high into the atmosphere and the vents were so intense and long, a lot of ash was produced that then fell to the ground. The whole island of San Vicente was flooded with ash, especially in the northern part [where the volcano is], but also in the southern part there were moderate amounts that made life very difficult for a couple of days because the ashes affect everything. They affected the water supply, so there were cuts, although that is changing because they are already fixing it. But the ash was everywhere and people had to clean up, put on masks.The ash also significantly affected Barbados, another island east of Saint Vincent, something that is not common for them because they do not have a volcano, but they had to deal with its effects due to the significant amount of ash that reached them, which forced them to close the airport. And of course, many people had to evacuate the island because of the eruption and many are in shelters. But in terms of the most catastrophic consequences of the volcanoes, everyone who lived next to the mountain could be safely evacuated and there has been no personal injury or death to mourn. But people have had to deal with the ashes for the past few weeks and its ongoing effects.but they had to deal with its effects due to the significant amount of ash that reached them, which forced them to close the airport. And of course, many people had to evacuate the island because of the eruption and many are in shelters. But in terms of the most catastrophic consequences of the volcanoes, everyone who lived next to the mountain could be safely evacuated and there has been no personal injury or death to mourn. But people have had to deal with the ashes for the past few weeks and its ongoing effects.but they had to deal with its effects due to the significant amount of ash that reached them, which forced them to close the airport. And of course, many people had to evacuate the island because of the eruption and many are in shelters. But in terms of the most catastrophic consequences of the volcanoes, everyone who lived next to the mountain could be safely evacuated and there has been no personal injury or death to mourn. But people have had to deal with the ashes for the past few weeks and its ongoing effects.Everyone who lived on the side of the mountain could be evacuated safely and there have been no personal injuries or deaths. But people have had to deal with the ashes for the past few weeks and its ongoing effects.Everyone who lived on the side of the mountain could be evacuated safely and there have been no personal injuries or deaths. But people have had to deal with the ashes for the past few weeks and its ongoing effects.

Q. You

have already identified modifications in the profile of the volcano. How is this eruption going to change the geography of the island?

A.

What is going to change is the top of the mountain where the volcano is. At the top of the volcano there is a crater about a kilometer in diameter. Inside the crater there used to be a rock dome and between December 29 of last year and before the explosions there was another amount of rocks, so there were two domes before the eruption started. When this occurred, it destroyed the one that was formed last year and a significant part of the one that was created in the 79 eruption. So now at the top there is a space with a hole in the crater. What will change is the shape and configuration of the top. The island itself is not going to undergo any major changes. Some deltas could form if a lot of deposition from the volcano gets together, the rivers could spread.

Q.

And what is the forecast for the next weeks and months? I understand that such an event cannot be predicted, but what do you expect to happen?

A.

In the coming weeks or perhaps months we could continue to see these types of explosive events from time to time. There may be one or two and then a period of inactivity and then another of explosions, which could extend for weeks or months. We believe that at some point, hopefully in a year or less, in a few months, it will run out of steam, that all the material that came out, all the magma, will exhaust it. And once that happens, the eruption should stop and people are going to have to deal with the effects. So far, there is no indication that it is going to stop or that we are heading towards the end. Although now we are in a period of decline of explosions there is always the possibility that more material will come out.

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