A strong earthquake swarm started under the area of La Cumbre Vieja volcano in the southern part of La Palma Island yesterday.
So far, more than 350 tremors have been detected, including 14 quakes of magnitudes above 3.0 and 226 quakes between 2.0 and 2.9.The strongest quake was a magnitude 3.4 event at 00.46 am local time this morning, which was felt by nearby residents.
Most earthquakes are at shallow depths around 8-12 km, suggesting that new magma is currently intruding into a reservoir under the volcano.
Whether or not this might be leading up to new volcanic activity is impossible to say, as there seem not to be other signs of significant volcanic unrest at this stage.
Seismographs and going frenzy on La Palma:
Similar earthquake swarms have occurred in the past as well, most recently in late December last year. However, during that event, the quakes were deeper (at around 30 km depth).
Has magma now risen higher in the volcano’s underground storage systems?
La Cumbre Vieja volcano last erupted in 1971, and it is considered one of the most active volcanoes of the Canary Islands.
Cumbre Vieja volcano lies on the southern third of La Palma,Canary Islands, and rises about 2 kilometers (1.2 mi) above sea level and 6 kilometers (3.7 mi) above the seafloor.
It is the fastest growing volcano in the archipelago and thus dangerous in terms of collapses and landslides.
Professor Stephen Sparks, one of the world’s most reputable volcanologists, said, “When volcanic islands emerge from the sea, they are very unstable. And, in some cases, huge landslides can happen when part of the island collapses into the sea…”
Humanity has never witnessed enormous collapses on La Palma and there is evidence that the western flank of La Palma is currently stable.
But as a Cumbre Vieja landslide tsunami may constitute a threat to Brazil, Canada, Caribbean, Ireland, Morocco, the Northeastern United States, Portugal and the United Kingdom, the current seismic unrest clearly need more monitoring. And aside from the tsunami hazard, the impact of a large collapse on people living on the island would be severe. The communities of El Paso, Fuencaliente, Los Llanos and Tazacorte are located on the unstable block. Cumbre Vieja is largely unmonitored and a flank collapse may begin with little forewarning.
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