La Palma volcano, Canary Islands erupts: spectacular lava fountains from several vents and lava flows

The La Cumbre Vieja volcano finally erupted after 8 days of intense seismic crisis this afternoon at 3.15pm. At least two eruptive fissures opened in the area of the Montaña Rajada mountains, located in the municipality of El Paso, and started to erupt spectacular lava fountains from at least 7 individual vents.
Particularly in the beginning of the eruption, the opening of the vents was accompanied by strong explosions generating dense ash plumes as the ground opened to give way to the lava shooting out from underneath. The area of the eruptive fissure is an unpopulated forersted mountain zone, and some forest fires were ignited, but quickly controlled. There are no reports of damages. People are advised to avoid the area. Prior to the eruption, around 50 people with reduced mobility had already been evacuated from nearby areas, and more evacuations are now in progress.
This marks the first volcanic eruption on the island since 1971. The volcano had been quiet until 2017 when earthquake swarms started to appear from time to time, sign of magma slowly accumulating in its deeper reservoirs. The last before the recent crisis was in December last year.
So far, the eruption is relatively small and the lava flows were reported to advance rather slowly, but it is possible that it might intensify. In an article on El País, Nieves Rosa Arroyo Díaz, the island chief of security and emergencies is quote: “the lava is coming down slowly, but we are worried about the speed it could pick up. … There is an outbreak of fire, but it is being controlled.”
Spanish Prime Minister Pedro Sánchez changed his original plan to fly to New York on Sunday and is expected to arrive in La Palma to address the situation with local authorities and the Defense Ministry. It is likely that an exclusion zone will be set up around the eruption site.
Video:

Video taken by our colleague Alba Martín at 6:10 p.m. #LaPalma #volcano #volcaniceruption #eruption pic.twitter.com/teJHgn8NZc

— INVOLCAN (@involcan) September 19, 2021

Precursors
The eruption today did not come entirely as surprise. Intense earthquake activity - with more than 5000 small tremors detected in few days - had preceded it since Sep 11, as well as significant ground deformation with up to 15 cm uplift. On Sep 13, the volcano's alert status was raised to yellow, because these phenomena could be seen as sign that magma had been accumulating at shallow depth. The yellow alert affected the municipalities of Fuencaliente, Los Llanos de Aridane, El Paso and Villa de Mazo, with around 35,000 people affected in total, according to El País.
A lull in activity during last Thursday to Friday was only to be replaced by renewed seismic activity that accelerated today. Still, it was probably not expected to go so fast from then on.
4 hours before the eruption, it culminated in a 3.8 quake at 11.16 am, which in hindsight is likely to have been the main event that opened a crack (or dike) towards the surface. In the hours before the eruption, volcanic tremor had been continuous and increasing as magma started to move until finally breaching the ground.