Thursday, December 9

La Palma volcano lava reaches the sea | Society


The lava from the La Palma volcano has reached the sea on the coast of the municipality of Tazacorte around 11 at night, Canarian time, around the area known as Playa de los Guirres (also called Playa Nueva), where it it has precipitated from a cliff about 100 meters high. The contact of the lava with the sea has created the emanation of a black smoke that is entering the land because of the night winds that go from the water to the land. The sea is shallow in that area, which will cause a new platform to be created relatively quickly.

The group of marine geosciences of the Spanish Institute of Oceanography, which is following the advance of the lavas directly, has detailed that “an impressive deposit of more than 50 meters high is being generated” in less than 45 minutes, which also continues to grow .

Shortly before ten o’clock on Tuesday night, the Canary Islands Volcanological Institute had reported that the wash had already crossed the so-called coastal road, located next to the Todoque Mountain, about 320 meters high, in the municipality of Tazacorte. The distance that separates the road from the coast is about one kilometer. This was the last major obstacle the lava flow faced before reaching the sea. The cut off of this highway left the neighborhoods of Puerto Naos, El Remo and La Bombilla practically isolated, also in Tazacorte, although the Cabildo had enabled alternative routes to access these populations.

Since it surpassed the Todoque Mountain, the lava has accelerated its path due to the steepness of the terrain and has devoured numerous banana plantations that took advantage of the fertile land in the area.

Today the island of La Palma has registered a total of 29 earthquakes in different points, from Villa de Mazo to Fuencaliente or El Paso, with intensity between 2 and 3.3 points of magnitude on the Richter scale.

The mouth of the magma in the ocean is a phenomenon that worries the authorities from the moment the eruption began last Sunday, September 19, because its reaction with the salty water causes toxic clouds. The only one who died from the Teneguía volcano in 1971, in fact, died from inhaling these gases. For this reason, the Civil Protection device has been intensified, because “it can generate explosions and emission of harmful gases,” according to the crisis committee (Pevolca).

The path from the lava to the sea, a destructive ten-day journey of some 50 million cubic meters of lava, has been erratic and unpredictable. After a few days of deceleration, the lava flow was reactivated last Sunday, the day in which it increased the speed in its advance towards the sea, a week after the start of the eruption of the volcano. This situation made it necessary to decree urgently, at midnight, the confinement of four population centers due to the danger of toxic gas emanations due to the interaction of magmatic material with seawater, given the possibility that the wash would reach the sea in the next few hours. in the coastal area of ​​Tazacorte, according to the emergency plan.

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This Tuesday, the director of the National Geographic Institute (IGN) in the Canary Islands, María José Blanco, reported that one of the volcano’s mouths, in the northern part, has slightly changed towards a Hawaiian behavior. In these types of eruptions, the process is usually calmer because the lava is even more fluid, gases are released easily and explosions do not occur. Until now, the authorities explained in all their appearances that it was a “fissure eruption Strombolian character ”, that is, the opening of a fissure in the mountain whose eruption is permanent, of fluid lavas and dotted with explosive outbreaks, like that volcano of Stromboli, in the Aeolian Islands, north of Sicily.

The advance of the lava is constant, after the two-hour hiatus on Monday morning, when the emission of lava, smoke and ash stopped. At 10.30 (local time) it was reactivated. These stops and returns to activity are common in this type of eruption. At noon on Monday, the lava path had been slowed down by the orography of the island of La Palma. This circumstance led the scientific committee of the Special Plan for Civil Protection and Attention to Volcanic Risk Emergencies (Pevolca) to doubt whether the lava would end up reaching the sea. “We don’t know,” declared its technical director, Miguel Ángel Morcuende. “If the conditions that were given at 8:00 pm on Sunday had continued, it would have already arrived without a doubt. But the volcano has times of growth and others of decay ”.

The new volcano could also be feeding back from a deeper lava reservoir, as happened with the underwater volcano of El Hierro, according to Carmen López, head of volcanic alert at the National Geographic Institute (IGN), in statements to Efe. López explained that the deep seismicity located in the last hours in the Fuencaliente area, with earthquakes of magnitudes between 3.3 and 3.4, are indicative of a readjustment of the reservoir in the crust as the magma comes out in the form of lava, ash and pyroclasts.

Increasing speed

The lava picked up a lot of speed late Monday afternoon on its way to the sea. Its movement, and resistance in various areas such as the Todoque Mountain, has widened on its way to the coast.

When the lava tongue, around a thousand degrees of temperature, reaches the sea, just over 20 degrees, there is an explosion of water vapor that generates a dense black cloud. Lava, with its extreme heat, causes this plume, but also a chemical reaction, mainly involving chlorine, which can irritate the skin, eyes and respiratory tract. In total, there are four main hazards associated with lava flowing into the ocean, according to the United States Geological Survey: the sudden collapse of the land and cliffs of the coastline, the explosions triggered by this collapse, the waves of boiling water that are generated in the environment and, finally, the column of toxic steam with hydrochloric acid and small particles of volcanic crystals.

But not everything is destruction when the sea interacts with a volcano, as could be observed in the recent submarine eruption in El Hierro, in 2011. The oceanographic research vessel Ramón Margalef Saturday arrived to study in detail the entrance of the lava into the sea. The ship will also collect rocks and coral from the area. These organisms absorb sulfur and other gases spit out by the volcano, so the Margalef He also hopes to study the impact that the massive influx of lava will have on fauna, explains Eugenio Fraile, a researcher at the Spanish Institute of Oceanography. “The most affected will be the organisms that live attached to the seabed and that cannot move, which will probably die. But recovery can be quick. Three years after the eruption of the underwater volcano of El Hierro, these organisms had been almost completely renewed ”, he highlights.

One of the possibilities is that the sea turns turquoise green, forming a huge spot that could be observed from space. This is what happened in Hawaii in 2018. The entrance of the molten rock displaced the most superficial layers of water so that the deeper ones rose, which have many more nutrients and favored the growth of algae that stained the water.

Home to home map of the La Palma volcano advance

The ship will also map the seabed after the eruption and will be able to compare that bathymetric map with the one it already made in 2018, when La Palma was already shaken by a swarm of earthquakes. The vessel will collect rocks and coral from the area. These organisms absorb sulfur and other gases spit out by the volcano. The coast of La Palma is a marine reserve and the Margalef He also hopes to study the impact that the massive influx of lava will have on fauna, explains Eugenio Fraile, a researcher at the Spanish Institute of Oceanography. The most affected will be the organisms that live attached to the seabed and that cannot move, which will probably die. But recovery can be quick. “Three years after the eruption of the undersea volcano of El Hierro, these organisms had almost completely renewed themselves,” Fraile points out.

At the moment there is no estimate of how long the volcano will continue to spit lava. The longest eruption of all that have been documented on La Palma is that of Tehuya, which occurred in 1586, which lasted 84 days. The shortest, on the other hand, was the one that until this Sunday was the last on the island, that of Teneguía, in 1971, which lasted 24 days.




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