“Landslides and Tsunamis are phenomena that have already occurred in the Canary Islands for many thousands of years, and that can occur again in the geological future of the Canary Archipelago ”, he assures the volcanologist Joan Martí, director of the Barcelona Geosciences Institute, belonging to the Higher Council for Scientific Research, who has studied the geological cascading process experienced by Tenerife 170,000 years ago and who follows the eruption of the volcano on La Palma.
However, Martí places the possibility of a tsunami in the Canary Islands in the future. “I would say that at present it is not likely to happen,” he says. “A tsunami could happen, but it is not likely”, highlights. In turn, he explains that “for a situation of these characteristics to occur, a much stronger and more intense seismicity and energy production than has been recorded until now is necessary.” Thus, he concludes that “Right now, the conditions are not right for a fissure, a landslide or a tsunami to take place”.
Joan Martí knows what he is talking about, as he has commanded a research team specialized in reconstructing extreme geological events that cause great natural hazards. The work studies the geological process in the cascade of Tenerife, a process that had as a last effect a great tsunami that affected the entire Canary Islands.
His research on volcanic risk in Tenerife sees the light at a very interesting moment for volcanologists, with the volcano of the Cumbre Vieja massif, in La Palma, in full eruption. This is the first surface eruption in Spanish territory that can be rigorously studied. When the Teneguía eruption, was analyzed by researchers from the Higher Council for Scientific Research (CSIC) and a University of Madrid, but now, with live images from televisions, scientists have at their disposal a very useful document. “We have the ability to observe the different phases of the volcano and we can learn a lot, for example, about how the first moment of the explosion was, the lava coming out, how it stopped for a few hours and how it was reactivated later,” he details. All this, he says, “gives us indications of how it works, when seen live, and allows us to gather very valuable information for the future.”
Regarding his work on the geological phenomena in cascade that Tenerife suffered, published in the Journal of Geophysi cal Research: Solid Earth, concludes that they can occur again “in a geological future because the conditions that occurred continue to occur today.” He points out that it does not mean that it will happen tomorrow, “but that it can happen within the geological evolution of Tenerife”, something that implies the passage of thousands of years.
These phenomena in Tenerife began with a large eruption, which caused a collapsing boiler, which triggered the seismicity. This in turn caused a landslide, which led to a tsunami as the material fell into the sea. “Each of these processes should have taken place in hours or days,” explains Martí. The first link in the chain took place in the eruption of the Las Cañadas caldera (where Teide is today), after which the entire volcanic building collapsed and an emission of volcanic material covered almost the entire island.
All this triggered high levels of seismicity along the fault, which accelerated a landslide to the north of the island, which gave rise to the Icod valley, and a landslide in its central northern part that led to the subsidence in the sea of 100 cubic kilometers of land, a large block that collided with the sea “and caused a tsunami that affected all the Canaries.” The result was a sea level rise of 150 meters to the Tenerife coast. “Deposits belonging to this tsunami have been found in Tenerife, at a height between 130 and 160 meters above sea level, with thicknesses of more than 10 meters,” says Martí.
The Catalan researcher also directed a master’s degree five years ago in which he pointed out the high danger of the existing hot spot in the Cumbre Vieja area where the volcano emerged that has been erupting for two weeks. “This was the area most likely to have an eruption; We already said that, if an eruption occurred, it would occur here ”, he highlights. Likewise, it warns that the fact that in the Canary Islands volcanic events have repetition periods every 50 years forces us to act on planning thinking in the long term and advocates that spatial planning plans take these risks into account, especially for prevent the affected population from losing everything.