The seismic swarm that, since last Saturday, shakes the surroundings of the Cumbre Vieja volcano, continues to be active. In fact, in the opinion of David Calvo, head of Diffusion of the Volcanological Institute of the Canary Islands (Involcan), the more than 920 earthquakes located over the last few days in this area denote that we are facing a “very energetic process” that, hopefully, keep evolving. In this sense, the expert indicates that the fact that there has been a six-centimeter deformation of the island’s crust – quadrupled in 24 hours – denotes that “we are continuing to take steps towards a potential eruption”, although it cannot be calculate when this will happen: it can be weeks, months or even years.
As data to take into account, in the first instance, the shallow depth at which the tremors take place. According to the information collected by the National Geographic Institute (IGN), only yesterday there were 20 earthquakes with a distance of between 1 and 3 kilometers from the surface; many of them, felt by the population of different municipalities, but especially of the four that remain on alert: Los Llanos de Aridane, El Paso, Fuencaliente and Mazo, which are joined, by indirect affection, Tazacorte. Furthermore, in the Aridanense neighborhood of El Remo, rockslides occurred from the top of a hillside, which, Calvo acknowledges, “must be a direct consequence of the earthquakes.” “It is habitual. In 2011 we saw many in El Hierro ”, he specified.
Asked about the figure from which it can be considered that the deformation of the terrain is a symptom of an imminent eruption, the head of Difusión explains that “there is no certain value”, because in some places the volcanoes have exploded with just a few centimeters and in others this variation has had to reach several meters. Herrera’s antecedent points to a range of 12 to 15 centimeters, but, as it is a “different” volcanic structure, the thresholds can be radically different, as the head of Involcan Surveillance, Luca D’Auria, acknowledged to DIARIO DE AVISOS. What is clear is that the “magmatic intrusion” attributed to the current Cumbre Vieja swarm will not suddenly turn off, rather, assuming it is deactivated, it will do so “little by little”, to the same extent as that “loses energy.”
To observe this phenomenon, instrumentation from both IGN and Involcan is being used. The first organism has inclinometers that have made it possible to measure the deformation of the palm bark, although not to locate it with precision. For this task, the seven GPS stations that Involcan has installed in La Palma, which have located these alterations on the coast of Los Llanos de Aridane and the area of Montes de Luna (Mazo), are useful, coinciding with the first conclusions, which pointed to the west slope as the one that is giving the greatest space to the movements of the magma. These two types of devices will be joined, in the next few hours, by the Sentinel satellite of the European Union.
Precisely on Tuesday, at the request of the Geological and Mining Institute of Spain (IGME), the Central Government Delegation in the Canary Islands requested the activation of the so-called Copernicus program of the European Union. A plan that, under the auspices in our country of the National Center for Monitoring and Coordination of Emergencies (CENEM) and with the technique of interferometry, allows obtaining aerial images of a specific point on the globe. On this occasion, to locate more precisely where there are deformations and, therefore, where the magma is moving, which is “looking for a way out,” recalled D’Auria, while pointing out that the scenario could not be ruled out that , at a certain depth, stopped.
On the other hand, Involcan has sent a delegation of experts to Isla Bonita to work on the ground and extract data in situ. Thus, up to four professionals from the Institute will be in charge of these tasks from today. Furthermore, David Calvo affirms that “we are in contact with prestigious international collaborators”, belonging to institutions in the United States, Japan and Italy, among many other countries.
It should be remembered that the episode that Isla Bonita is currently experiencing dates back to September of last year. Since 1971, when the Teneguía erupted, until 2017, there is no evidence of seismic activity in the island territory. Since then, seismic swarms have been recorded, and by the end of 2020, Involcan’s geochemical monitoring system detected the highest levels of helium-3 in the last three decades. The Cumbre Vieja volcano was activated. A process of “magmatic intrusion” began, although at a depth of around 20-30 kilometers, compared to the 10 that are being handled now.
The Scientific Committee provided for in the Pevolca (Civil Protection and Emergency Assistance Plan of the Canary Islands due to Volcanic Risk) decided yesterday that the four municipalities that were on a yellow traffic light due to the risk of an eruption continue at the same level, since the scenario has not changed enough to foresee an imminent event. In addition, the Cabildo palmero has developed new informative materials to prepare the population for a virtual precipitation of events. This was declared to the DIARIO by the insular councilor for Emergencies and Security, Nieves Rosa Arroyo, who insisted on the coordination that has been carried out with the municipalities and the message of tranquility to the residents.
Another noteworthy aspect is that officials from the El Paso City Council have gone to various homes in the municipality, and specifically in the neighborhoods of Jedey and Las Manchas, “to transmit calm, gather information on people who may have mobility problems, find out which families they had animals and inform the neighbors about the preventive indications that Civil Protection sends us about the importance of being prepared in case of the possibility of an evacuation ”, described yesterday the mayor Pasense.