A two-stroke shake on La Palma

Two strong earthquakes struck La Palma, La Gomera and Tenerife yesterday morning. At 7:27, a strong and prolonged tremor, preceded by a loud guttural roar, whose energy was able to cause the buildings to vibrate, causing those inside to see how walls, objects and some furniture were shaking for at least 10 seconds in The Palm. The wave spread to La Gomera and Tenerife, with less force, but also generating a slight, albeit long, vibration in those people who were still sleeping in Tenerife and La Gomera.

After several reviews, the National Geographic Institute (IGN) was able to determine that what had generated such a movement in the earth had not been one, but two earthquakes in a row of great magnitude, separated by only three seconds apart. One of them, the first to be felt, had a magnitude of 4.8 and occurred at a depth of 36 kilometers. The one that preceded it was somewhat larger, of magnitude 5 and produced at a depth of 35 kilometers. In the day yesterday there were just over 80 earthquakes throughout the day. Of these, only nine including these two – occurred in the deepest magmatic pocket, which is between 35 and 37 kilometers deep. The rest were produced between 10 and 14 kilometers, where it is thought that there is another magmatic pocket from which the volcano is constantly being fed back. In recent days, the percentage of earthquakes that occur at greater depths has decreased. This, according to experts such as the volcanologist from the Institute of Natural Products and Agrobiology (IPNA-CSIC) could denote that the volcano is now feeding from the shallowest pocket instead of the deepest. The same scientist insists that these tremors are “normal” during the eruption – they also occurred in El Hierro – and recalls that they can be maintained even after the eruption ceases. Of course, if the eruption ceased and the earthquakes were kept very close to the surface  (more than now), the volcanologist would see alarm signals before the possible exit of a new distant mouth.