Incandescent lava still flows into the solidified earth around the volcano.an. From the cracks that have formed in some of its volcanic tubes, it can be seen, several meters deep and with great precision, how the lava, of an intense red color, continues to travel through these new spaces formed by the volcano. And it does so at more than 800 degrees Celsius despite the fact that it has been almost a month now thate the volcano decided to go out permanently.
This inner fluid will continue to register high temperatures for an indeterminate time.
This image, although surprising, it is a natural part of the eruptive process. As the seismologist of the National Geographic Institute (IGN), Itahiza Domínguez, this image happens because "lLayers of lava and cold volcanic material are poor conductors of heat ”. When the outer lava solidifies, in contact with the environment at a much lower temperature, the inner lava remains almost at the same temperature as when it was violently emitted by the volcano. "The interior materials are kept at a high temperature for a long time", Domínguez highlights.
This happens in most volcanoes. In some, incandescent material has been found that can create another small tongue of lava months after the completion of the eruption. This can happen if, for example, a lava tube breaks. In other volcanic sites, such as the one left by the Timanfaya eruption (Lanzarote), "high temperatures can still be found if a hole is made in the ground", despite to have happened more than 300 years ago. And on the island of Fogo (Cape Verde), which suffered a volcanic eruption in 2014, several years later the inhabitants still had problems to build on top of the lava, since the heat that emanated from its interior melted any supply installation that wanted be done for homes.
So, for a while, I was alson La Palma the lava will continue to flow silently in the recesses that have not yet cooled, especially near the volcanic cone where, over the 85 days that the eruption lasted, "a lot of material" has accumulated. "This will happen for a long time and, above all, in the first phase after the volcano is extinguished, since there is still a lot of molten material inside."
For this reason, it is necessary to "wait a while" before starting to build or construct roads above the wastes. "It can be a problem," explains Domínguez, who clarifies that this can happen especially in higher heights. "Another difficulty is that the streams settle as time passes, so that at first building a road can be counterproductive," insists the IGN researcher.
In the same area where scientists have seen lava flowing at a high temperature, there is a fracture in the crater with gaseous emissions of sulfur dioxide and with temperatures reaching 500 degrees. The gases are released from the lava as it cools because "they are dissolved in the lava and when it changes state, the fluid part lets them escape."
With a degassing - both of sulfur dioxide and carbon - that affects a large part of the perimeter flooded by the lava of the volcano, the question is when will it stop emitting gases? Scientists are not clear. "It is difficult to know exactly because it depends on the cooling capacity of the material and the amount of molten material that is still under there," says Domínguez. It should be remembered that the volcano has expelled, according to the latest balance of the Pevolca Scientific Committee, 160 million cubic meters of lava and 20 million cubic meters of tephra (ash). In fact, this weekend the Canary Islands Volcanological Institute (Involcan) warned that it had found anomalous concentrations of carbon dioxide (CO2) in the basement of some buildings in Puerto Naos (Los Llanos de Aridane) and pointed out that its origin is related with the volcanic-hydrothermal activity after the end of the La Palma volcano eruption. These anomalous concentrations of CO2 were also detected inside buildings in the same palm locality.