Timon .:. | Thu, September 30, 2021 | 0
La Palma eruption intensifies and could last 24 to 84 days, INVOLCAN estimate
The Volcanological Institute of the Canary Islands (INVOLCAN) has estimated that the current volcanic eruption on the island of La Palma could last between 24 and 84 days.
The calculation was made based on known data about the duration of historical eruptions that have occurred on the island, although they point out it is a “question that is not easy to answer.”
“Therefore, it would be acceptable to convey that we move in the range of a duration between 24 and 84 days, with a geometric mean in the order of 55 days,” they indicated this Wednesday morning.
The institute also points out that the Canary Islands Seismic Network during Tuesday afternoon detected a “strong increase in the amplitude of the volcanic tremor” at Cumbre Vieja, which is an indicator of the “intensity of the strombolian explosive activity from the active mouths at this moment”.
The Canary Islands Government PEVOLCA team, coordinating the Special Plan for Civil Protection and Attention to Emergencies due to Volcanic Risk of the Autonomous Community of the Canary Islands, have said that the eruption “continues to show the same fissural eruptive style, with a strombolian mechanism”.
The newest mouth is “very close to the other active ones.” The approximate average speed of advance of the front of the lava flow is now 200 m/h, “continuing its advance towards the sea”, with a “maximum thicknesses of around 10-12 meters”.
The bulletin also referred to a shallow earthquake, at 9:32 p.m. on Tuesday, that was registered southeast of Tazacorte, at a magnitude of 3.8 mbLg, “succeeded in the hours following by two earthquakes also felt southwest of El Paso.”
They estimate that “volcanic gases emitted could reach 3000 m in height (according to VAAC of Toulouse)”. The current estimate of the rate of emission of sulphur dioxide (SO2) into the atmosphere is now between 8000 and 10,600 tons per day, the update highlights.
Over recent hours there has been a change in the direction of the air flows in the lower middle levels of the troposphere, at around 3000 meters, turning from the west to the north/northeast, causing a shifting of the plume, southwest of the emission source.
On the west-facing slope affected by the eruption, breezes of between 10 and 20 km/h are expected and predominantly from northeasterly winds. “Acid rain has ruled out for the next 24 hours,” they report.
Finally, scientists reminded everyone that “the moment the lava flows reach the coast”, it could “generate explosions, emanations of gases and a detachment of the lava front”.
“An exclusion radius of 2 kilometres around the emission centres is recommended to minimise the risk of impact from pyroclasts and exposure to gases. It is also recommended not to approach lava flows due to the risk of exposure to gases emitted, possible detachments and high temperatures “.
The only reported fatality during the last eruption, in 1971, was that of a fisherman who inhaled toxic gases nearly 2km from where the lava met the sea, so extreme caution is advised.