The three great landslides that have occurred this summer in Tenerifethe last one last Sunday on the cliffs of Los Gigantes, in the municipality of Santiago del Mount Teideare «normal in the Islands due to their characteristics» and «they have no relationship” with the seismic swarms recorded in the Teide National Park. This is defended by two scientists who work to control natural risks in the Archipelago: Elizabeth Montoya, geologist at the Geological and Mining Institute of Spain (IGME), and Itahiza Dominguezseismologist at the National Geographic Institute (IGN).
Isabel Montoya assures that the avalanches are «normal in islands like the Canary Islands» and that the fact that these last three episodes have coincided with a period in which there have been two swarms of earthquakes on Teide is «a coincidence that has no reason to be related». «We do not have any data that relates the landslides with the volcanic activity on Teide. They occurred at a time great citizen sensitivity due to the succession of small earthquakes on various specific dates in the National Park but there is no data that points to a connection”, details the IGME researcher.
Volcanic activity can cause avalanchesas in fact happened in the days before the Tajogaite eruption in La Palma (September 19, 2021). However, these are exceptional cases in an Archipelago in which its highest islands –Tenerife, La Palma, Gran Canaria and El Hierro– register at least one avalanche of some size per week due to other factors beyond volcanic activity: strong slopes, rains, instabilities in the terrain, human action…
Itahiza Dominguez, a member of the IGN team in Tenerife, considers that not even the landslide on June 17 – the first in this series – on the north face of the Teide cone has anything to do with the earthquakes associated with the activity of an awake volcano, but which it does not threaten for now to erupt. And that despite the two swarms of hundreds of earthquakes recorded on June 10 and July 13. “Earthquakes of very low magnitude, such as those recorded in the last two swarms in Teide National Park, do not produce avalanches of this type on the surface,” explains Domínguez. The seismologist clarifies that some of these slides, especially those that drag more earth and rocks, they do leave a mark on the seismic stations of the National Geographic Institutelike the same one on Teide on June 17.
That avalanche has a peculiarity: it is the first confirmed by the IGN in the volcano. Although there is evidence from the geological traces that this face of the volcano is predisposed to suffer small landslides, until now it has been difficult to confirm that they happened, since they occur “in uninhabited areas”, as Itahiza Domínguez details.
The IGN seismographs have captured these signals on several occasions, which differ from the one that can be emitted by a seismic event. “We were almost sure that they were small landslides, but it has not been until now that we have been able to confirm one in this area,” the researcher stressed on June 21, five days after the landslide. They have not been able to do so so far because there has been no evidence to prove it. However, on this occasion, the video of a neighbor in the northern area – far from the place where the landslide occurred – was able to capture the moment.
The second of these detachments in Tenerife took place on Tuesday, July 26, on a cliff in the municipality of Icod de los Vinos. There is also a video recorded by a neighbor of this episode. Twitter user Simón de la Rosa shared a video on his profile in which the detachment of part of the slope towards the sea can be seen. A few hours after the video began to go viral, Itahiza Domínguez himself shared the images, explaining that “it is not uncommon for landslides to occur on the Islands.” A day later, the IGN explained on its Twitter account that several of the island’s seismic stations also recorded this landslide.
The last of these avalanches It happened last Sunday and it has also been known by the video of a citizen recorded with the mobile phone. In the images you can see the dust that comes off the fall of earth and stones on the cliff of Los Gigantes. «The time is almost exact because I heard the rumor of the collapse and I immediately started recording. The video was saved at 14:26 but it was a moment before. Let’s see if it helps, although this one didn’t make much noise,” said Twitter user Chano Escuela (@ChanoEscuela) in one of the comments accompanying the images.
