almost 400 tremors in 72 hours

Yurima Celdran Yurima Celdran Meteored Spain 4 min
Tremors in Spain
Cumbre Vieja volcanoes, La Palma.

The National Geographic Institute has detected since the beginning of the earthquakes, on September 11th at 3:18 am UTC, until today, Monday 13th, at 1:58 pm UTC, a total of 397 tremors in the municipalities of Mazo and Fuencaliente, south of the island of La Palma.

Earthquakes are located at depths ranging between 8 and 13 kilometers.

The magnitude of these earthquakes has progressively increased, their intensity, on a regional mbLg scale, went from 2 and 2.9 mbLg to more than 3 mbLg in the last hours. So far, the strongest event rocked the island last morning around 00:46 with a maximum intensity of 3.4 mbLg. This was felt by nearby residents.

Background

La Cumbre Vieja volcano, a 2,426 meter high shield volcano, is located south of the island of La Palma. This volcano last erupted in 1971 and is considered one of the most active volcanoes in the Canary Islands.

This area of ​​the island has suffered up to nine seismic series with characteristics similar to the current ones since October 2017. It should be clarified that this type of event is within the normal range and does not pose any risk to the population.

Current image of earthquakes south of La Palma: yellow magnitude less than 2 mbLg, orange between 2 and 3 mbLg, and blue in the last tremor. National Geographic Institute.

Without going any further, last June there were more than 80 earthquakes of less than 2.5 mbLg in the same area and with characteristics similar to the current ones, despite the earthquakes having occurred at greater depths, between 18 and 34 km. This last episode, started last Saturday, 11, it has been the most intense, both in terms of the number of localized earthquakes and their magnitude.

Current situation

The shallowness of these new earthquakes suggests magma seeping into a reservoir below the volcano. Although similar earthquakes have also occurred in the past, these are deeper, which could indicate that the magma is now higher in the volcano’s underground storage systems. In addition, the geochemical monitoring of volcanic gases highlighted that the recorded data of helium-3 emission confirm the great magmatic character of this process, and indicate that it is the largest data observed in the last 30 years.

The population must pay attention to the information provided by the Civil Protection authorities.

It is for this reason that the Ministry of Public Administration, Justice and Security of the Government of the Canaries convened today the Scientific Commission of the Special Plan for Civil Protection and Attention to Volcanic Risk Emergencies (PEVOLCA) to assess the situation, agreeing to activate this Plan in an Alert situation for Fuencaliente, Los Llanos de Aridane, El Paso and Mazo and the change from green to yellow light for these municipalities.

At the current level, the activity does not entail an increase in risk for the population.

PEVOLCA establishes a volcanic signal as a population alert system based on four colors depending on risk. At the yellow level, information to the population is intensified, the surveillance measures and monitoring of volcanic and seismic activity, not being ruled out the possibility that the seismic activity will be felt in the coming days.