La Palma volcano creates new delta in the sea, prompting authorities to confine 3,000 people

The lava flowing from the volcano on the Spanish Canary Island of La Palma made new contact with the sea on Monday, at around 12pm local time (one hour behind Spain). The risk to residents of the gases that emanate from the water when the molten rock makes contact prompted the authorities to confine around 3,000 residents of the municipality of Tazacorte. The new delta formed by the lava is in an area known as El Perdido, located some three kilometers south of the Tazacorte port and some two kilometers from the other delta that came into existence on September 28.

The tongue that reached the sea on Monday has been receiving the largest amount of lava in recent days from the center of the eruption, which began on September 19 and shows no sign of letting up right now. The sudden contact with the ocean was “another surprise from this volcano,” according to Miguel Ángel Morcuende, the technical director of the team of experts monitoring the phenomenon, the Volcano Risk Prevention Plan (Pevolca).

At the same time, lava is still reaching the first delta, which grew another seven hectares in surface area in just a day to a total of 1,068 hectares. The lava has destroyed a total of 1,481 properties, according to data from the public land registry. Of these, 1,193 were residential homes.

When molten rock, which has a temperature of around 1,000ºC, reaches the 20ºC sea water off La Palma there is an explosion of steam that generates a dense black cloud. The lava also creates a chemical reaction, mostly of chlorine, which can irritate people’s skin, eyes and respiratory tracts.

According to the United States Geological Service, there are four main dangers associated with lava flowing into the ocean. These are: the sudden collapse of the land and cliffs on the coast; explosions caused by such a collapse; waves of boiling water; and a column of toxic steam containing hydrochloric acid and small particles of volcanic crystals.

These risks prompted Pevolca to confine residents in Tazacorte, which is home to 2,500 people, as well as San Borondón (this is the third time it has been locked down since the eruption started), and part of the population of El Cardón.

Miguel Ángel Morcuende warned on Monday that the air quality in the east of La Palma would continue to make local air travel impossible. On Tuesday, Spanish air authority Aena announced that the airport on La Palma would remain closed for a fourth day due to the dangers presented by the volcanic ash. Binter, an airline that runs routes between the Canary Islands, also confirmed today that all of its flights would be canceled.

A tweet from EL PAÍS reporter Guillermo Vega showing the ashfall on La Palma.

The use of FFP2 masks was also recommended, as well as avoiding open-air activities in the municipalities of Santa Cruz de La Palma, Breña Alta and Breña Baja (in the east of the island).

The emission of sulfur dioxide from the volcano dropped sharply from Sunday to Monday, to around 900 to 1,300 tons a day. Pevolca spokesperson Carmen López said on Monday that this does not necessarily mean that the eruption is losing energy, and said that the data point would have to be monitored over the coming days. The emission of this gas constitutes one of the most trustworthy measures for the intensity of the eruption.

The National Geographic Institute detected 43 earthquakes on Monday night. Of these, three were stronger than 4 on the Richter scale. The biggest tremor, measuring 4.8, was in Villa de Mazo at a depth of 39 kilometers, and took place at 1.03am. Seconds later, another tremor measuring 4.7 was detected in the same place.