The La Palma volcano eruption had been in the works for four years
The eruption of the Cumbre Vieja volcano from La Palma has been preparing for four years, as suggested by a preliminary analysis of the data, writes the New York Queens College volcanologist Marc-Antoine Longpré in an article published today by Science.
The expert reviews the facts before and since it erupted explosively on September 19, demonstrating "a behavior contrary to that of basaltic volcanoes, data that offer "valuable lessons" for the forecast of eruptions, the evaluation of dangers and the management of risks in the Canary Islands and other similar volcanic islands.
Longpré writes that "With the disaster come opportunities" and consider that "identify and dissect" this eruption, which is produced after fifty years, "has enormous value."
Preliminary analysis of the data outlined by the expert "suggests that the eruption had been in the works for four years," starting with a seismic swarm in October 2017.
Subsequently, "the upheaval accelerated to the point where an eruption seemed likely only eight days before the magma broke the surface."
Longpré points out that "Significant explosiveness" of the eruption is somewhat "surprising" because the extent of this behavior was not clear in the historical records of the previous eruptions in the Canary Islands.
The current eruption is a "telling example" of how basalt volcanoes can simultaneously produce lava flows and considerable explosive activity, presenting an opportunity to reassess past eruptions in the Canaries along with related hazards.
In his article, the volcanologist considers that the reactivation and behavior of the volcano, after fifty years without activity, requires a rethinking of forecasts and risks.
The catastrophe has not directly claimed human lives, which he attributes "to the coordinated emergency response of the local authorities, who were well prepared", having gained experience in the management of volcanic crises during the underwater eruption from 2011 to 2012 near from the neighboring island of El Hierro.
For Longpré, "Another bright light in the dark ash clouds" is the international scientific cooperation effort, largely coordinated by the Instituto Vulcanológico de Canarias (Involcan), with multidisciplinary teams, on and off the ground, sharing data in near real time.
The eruption, he says, does not currently show any signs of abating, "which is expected" because historic eruptions have lasted between three weeks and three months.
When the eruption ends, “the resilient inhabitants of La Palma will recover and rebuild their communities. But someday, perhaps in the future far enough to challenge collective memory, the volcano will erupt again, in a different place, "he adds.
In Longpré's opinion, it is proposed “a social dilemma similar to that described in the Kilauea volcano (Hawaii): Will stakeholders do the necessary long-term planning to permanently reduce the risk associated with urban development on the flanks of Cumbre Vieja? "