How much material has the volcano emitted?


To answer the question of how much material, between pyroclasts and lava, this volcano has emitted that last September 19 emerged in the Cabeza area of ​​the El Paso municipality, in the southwest of La Palma, the Canary Islands Volcanic Emergency Plan (Pevolca) has commissioned an updated map of the Aridane Valley.

The new cartography will be contrasted with the one prior to the eruption, and what has been commissioned is a new digital terrain model (DTM), thanks to which it will be possible to accurately determine the height of the lava flows and mountains of ash, which in some areas have practically buried houses.

For almost a month, the estimate of the amount of material, between the cone and the streams, that the volcano has expelled in Cumbre Vieja has not been updated. Then the scientific committee spoke of a range between 80 and 100 million cubic meters.

That is more than the volcanoes of San Juan, in 1949, and Teneguía, in 1971, expelled it together.

The Timanfaya, in Lanzarote, it expelled 1,000 million cubic meters and the underwater Tagoro volcano, in El Hierro, 329 million.

Carmen López, from National Geographic Institute (IGN), points out to Efe that the estimates made so far from thermometry have been “very imprecise.” The range of values ​​is between 50 and 100 million.

The spokesman for the Canary Islands Volcanological Institute, David Calvo, tells Efe that the figure stands at around 120 million cubic meters this week, after taking an average of the measurements that have been made by satellite.

Hence the need for scientists to have a reliable tool such as an updated DTM, whose results would be added to the bathymetries being carried out by the Spanish Institute of Oceanography in the fajana that has been formed on the coast of Tazacorte.

What does seem clear is that the calculations of a month ago have been out of date given the great activity of the volcano, especially in recent days in which experts speak of “great avenues” of lava after different collapses and reconfigurations of the cone .

At first glance, “by mere observation on the ground”, what has been verified is that this greater contribution of lava material is making the flows grow in height.

In terms of occupied surface, it practically doubles in surface that until a month ago was the one that had covered the most surface with lava, that of El Charco in 1712, when it affected 441 hectares, according to the Volcanological Institute of the Canary Islands (Involcan).

Involcan quotes Carmen Romero, professor at the University of La Laguna, and the list of the eight historical eruptions of La Palma and the areas that occupied their respective lava flows is as follows:

1. Tacande 1430-1447 (424 hectares)

2. Tehuya 1585 (338 hectares)

3. Tigalate 1646 (296 hectares)

4. San Antonio 1677-1678 (210 hectares)

5. Charco 1712 (441 hectares)

6. San Juan 1949 (323 hectares)

7. Teneguía 1971 (276 hectares)

8. The new volcano (La Palma) 2021-? (779 hectares, according to data from October 18, which later updated the Copernicus system to more than 900)

Involcan qualifies that it must be taken into account that there are lava flows from some eruptions that overlap, such as the lava flows of 1585 and 1712, and those of 1677/78 and 1971.

Furthermore, only the emerged part of the streams is considered, so that except for the first eruption (Tacande), whose streams did not reach the sea, the total surface is always slightly higher than that considered for each eruptive event.

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