Canary Islands log 16 earthquakes in one restless week

At 9.35 pm on Friday evening, the measuring instruments at the Spanish National Geographic Institute (IGN) went off. An earthquake measuring 2.1 on the Richter scale had struck near El Hierro, with the epicentre at a depth of 27 kilometres. The Institute’s data is analysed by the European-Mediterranean Seismological Centre (EMSC).

By local standards, it has been a rather unsettled week: the IGN has recorded 16 earthquakes in the Canary Islands over the past seven days; over the last 30 days, there have been a total of 48, which works out at an average of 1.6 per day.

Exactly one third of all earthquakes over the past 30 days have therefore occurred in the last week. In terms of magnitude, there was nothing out of the ordinary: the earthquakes averaged 2, and the one off El Hierro, at 2.1, was only slightly higher.

Canary Islands: Minor earthquakes are a regular feature of the geological landscape

As the Canary Islands are of volcanic origin, minor earthquakes are a regular feature of the geological landscape there. The IGN and the Canary Islands Volcanological Institute (INVOLCAN) monitor activity on an ongoing basis. Seismologists and geologists do not automatically interpret a cluster of tremors within a short period as an increased risk, but they do keep a close eye on such phases.

Scientists are also monitoring the marine environment around the islands using methods other than seismic surveys. Off the coast of Gran Canaria, researchers are turning fibre-optic cables into sensors in the ocean. Meanwhile, in Tenerife, a drill was held in October in the south of the island to practise the response to a volcanic eruption, during which residents and tourists were evacuated.

Earlier on Thursday at 11.15 pm, the IGN had recorded an earthquake near Tenerife with a magnitude of 2.3; the epicentre was 20 kilometres deep. Also on Thursday, at 6.01 am, the earth trembled 50 kilometres off Gran Canaria with a magnitude of 2.5 at a depth of 17 kilometres. Finally, on Wednesday at 11.12 am, the stations recorded an earthquake 80 kilometres off Lanzarote with a magnitude of 2.4, the epicentre of which was 17 kilometres deep.