The eruption of La Palma could last for weeks or months: We are not fortune-tellers, it is impossible to know

"How long could the current volcanic eruption in Old Summit last? It is a very assiduous question that they ask us, "said yesterday the Canary Islands Volca

The eruption of La Palma could last for weeks or months: We are not fortune-tellers, it is impossible to know

"How long could the current volcanic eruption in Old Summit last? It is a very assiduous question that they ask us, "said yesterday the Canary Islands Volcanological Institute (Involcan) on their Facebook account. "Using the data we know about the duration of historical eruptions that occurred on the island of La Palma, a possible answer to this easy question could be obtained," the scientific organization continued.

"Therefore, it would be acceptable to convey that we move in the range of a duration between 24 and 84 days, with a geometric average of the 55-day order," he concluded in response in his response to such a pressing question as, Actually, impossible to answer with certainty. What is clear is that we do not find ourselves before a punctual emergency, nor do we know if the worst has already happened.

The estimate is based on the previous eruptions documented on the island of La Palma. The first one whose duration there is constancy is also the longest: the explosion of Tehuya, in 1585, which lasted for 84 days. The most recent, Teneguía in 1971, lasted 24 days and is the shortest one that is remembered.

Between one and the other, there have been four four eruptions with intermediate durations, as well as another in the fifteenth century, of which it is unknown how much it lasted, and the current one, with which no one still knows what will happen. In total, there are eight explosions that there is record in La Palma. From them, an average of 55 days is extracted. The figure is, in addition, similar to the 47 days lasted by the eruption of San Juan, in 1949, which is the most similar to the current one because of its situation and geological characteristics.

But the truth is that, as the Involcan itself aims, anything could happen. It is only the best possible forecast with the scarce data available. "This is so. You can shoot several weeks, a month ... and you can have a few days more activity and others, less, "says Pablo Gabriel Silva Barroso, Geology Professor at the University of Salamanca. "The only way to know something is to have historical documentation and see what has happened on previous occasions," he confirms.

"Both in Volcanism and in seismicity we use the catalogs of historical events. It is the only way to know what has happened and with what magnitude, both earthquakes have taken place as historical eruptions. There is no other way, it is the tool we have, "Silva continues. «First it was when the eruption will take place; Then, when will it come to the sea; And now, how long it is going to take ... but, of course, we are not tellers. That is impossible to answer, "he adds.

An indicator that the volcano will calm down when the bulging of the terrain caused by the lava is reduced. But that has not happened yet, the opposite. On Sunday, the deformation of the land was 15 centimeters, and now it is around 20 meters away. "The deformation of the island has grown," says Silva. "What does that mean? That there is still magma injecting into the base of the crust. Until the terrain does not stabilize and bulge - volcanic tumescence - does not start falling, we can not expect it to be calmly.

«First you have to stabilize bulging. Once it stabilizes, you will have to start going down, because you will be emptying the magmatic camera that feeds the volcano, "Anticipates Silva. "That would be an unequivocal sign that he entered a phase of relaxation, because the magmatic chamber would be empty. Initors it takes a few days, a few weeks, or whatever ... ». At the moment, nothing provides that underground magma is being reduced. In fact, the first estimates spoke of 11 million cubic meters of lava, which the last models elevate 20 million.

Meanwhile, the main lava pouring, whose frontal reaches 15 meters high, barely moved yesterday on its way to the sea, although it did expand until it occupies almost 150 hectares, which were 100 the day before.

His speed of falling towards the ocean, which is no longer clear that he will arrive at any time, has been dramatically reduced, from 700 meters per hour to those who escaped last Sunday of the Old Summit Volcano until the only four kilometers per hour they were measured on Wednesday afternoon.

The reasons for the abrupt deceleration of Magma have to do with their great viscosity, which prevents it from moving faster and is, in turn, directly related to the explosiveness of the volcano. To this is added the fact that it has reached a flatter terrain, in the neighborhood of allow, where it has been almost stagnant.

Its destructive capacity, unfortunately, remains intact despite the slowdown of its sinister journey. It has devastated a total of 320 homes and buildings as a step.

Updated Date: 23 September 2021, 00:23

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