La Palma: 85 Days of Eruption and 215 Million m³ of Material

La Palma: When 85 Days of Eruption Buried 1,500 Homes

Seismographs had been recording hundreds of tremors beneath the Cumbre Vieja ridge for days. Then, the earth split open. An 85-day eruption began, spewing 215 million cubic meters of material and burying over 1,500 homes under lava.

No one disputed the severity of the event. What was heavily — and fiercely — debated was the information being disseminated. Official data arrived late, live TV broadcasts were interrupted for other news, and drones flying over the lava flows were confiscated by police. In this information vacuum, thousands became amateur volcanologists, watching the volcano directly.

The Numbers of an Unrelenting Eruption

The figures left by Cumbre Vieja — unofficially nicknamed 'Paco' in online forums — are difficult to comprehend. In 85 days, it ejected 215 million cubic meters of material. For perspective: initial estimates spoke of 11 million cubic meters. Then came 17, 20, and 26. The final figure far exceeded the first official projection.

Lava flowed at 50 cubic meters per second, with fountains reaching 60 meters high. A continuous stream that, according to one observer's calculation, would require "2,500 simultaneous fire trucks" to match with concrete. The flow traveled 6.5 kilometers from the cone to the sea, wiping Todoque off the map and forming a new delta where the ocean once was. The eruption also forced airport closures and school suspensions in five municipalities due to ash.

The emergency management also produced figures. 6,000 people were evacuated, 8% of the island's population. A widely shared analysis drew a comparison: if this proportion were applied to the Community of Madrid, half a million people would have needed evacuation. Where did these people go? Where did they sleep, eat, shower? "We saw more Syrian refugees than evacuees from La Palma," summarized one of the most read reports.

The Information Blackout Nobody Asked For

Complaints about official information are a recurring theme throughout the process. Local media outlets, with minimal budgets and mobile phone cameras, provided better coverage than major networks. Televisión Canaria even interrupted a live eruption feed to broadcast vaccination information. And when it wasn't TV, it was the police: a private citizen who had deployed his own drone to film the lava flow had it confiscated.

"They provide impeccable information. At this hour, the lava is near Panama," joked one trinc. Another, more technical, denounced the lack of transparency: "We don't even know the current height of the volcanic cone. By eye, 100-140 meters." He added: "There's no one in charge of providing information to the media; TV and press are more lost than a sardine in the Pacific Ocean, giving obsolete information from 2 days ago."

The result was a kind of improvised collaborative journalism: Copernicus satellite captures, foreign broadcasts, amateur drone footage, and transcriptions of press conferences. Anything was valid to find out where the lava was heading before the news bulletin.

Ash, Laze, and Risks Not in the Headlines

While television focused on the pyrotechnic spectacle, forums spread warnings about the volcano's chemistry. The so-called volcanic "ash" is not ash, it was argued: it's pulverized rock, and inhaling it causes the moisture in the lungs to turn it into mud. When lava contacts seawater, rapid cooling turns sand into glass, and these microscopic fragments are released with the steam, forming "laze" — an aerosol of crystals that, when inhaled, cuts lung tissue.

This wasn't alarmism. Official data confirmed particle levels exceeding 200 micrograms per cubic meter in several municipalities, leading to airport closures and school suspensions. The smell of rotten eggs reached the west coast for the first time since the eruption began. "The house is permeated with that smell, I hope it's not too toxic," wrote a resident.

Prolonged exposure to these gases and particles, some warned, is particularly dangerous for people with pre-existing respiratory conditions. Others focused on wells and water quality: to date, they pointed out, there has been no public announcement of a specific plan for bottled water supply or systematic analysis of groundwater in the entire affected area.

The Tsunami That Never Came

One of the most repeated arguments in the early weeks was the theory of Cumbre Vieja's collapse and the subsequent megatsunami that would devastate the US East Coast. The hypothesis originated from a Californian university professor. New York's emergency plans included a potential tsunami originating in the Canary Islands, which was enough for some sectors to consider it almost imminent.

From the outset, there were those who offered a technical counterpoint. "This eruption originated at the base of the ridge, so there was no risk of it breaking off and falling into the sea," explained a veteran analyst. "The seismic activity is occurring at Teneguía, at 439 meters altitude. Cumbre Vieja is 1,949 meters high. The apocalypse would have been a massive explosion at the summit, and that didn't happen." Time proved them right. The lava delta reaching the sea has its weight, but it didn't sink any islands.

The episode did, however, leave an uncomfortable lesson: minority geological theories, decades old, became trending topics while official bodies continued to withhold clear data on the subsurface's actual composition and the seismic swarm's dynamics.

The Experts Who Never Agreed

The list of failed predictions could fill a crisis management manual. "Sunday before the explosion: no need to increase the alert level." "It will just be a slight bulging of the ground and little more." "No problem when it reaches the sea, just a few little fish will die." "The lava will reach the sea on Monday at 7:00 AM, not 8:00 AM, it won't happen on Tuesday at 8:00 AM." "The volcano could be active for a few days, a couple of weeks, or a couple of months." Phrases like these circulated in forum discussions, attributed to statements and declarations by experts and public officials.

Furthermore, the director of the IGN in the Canary Islands coined a new term to describe what was happening: "strombolian eruption with continuous effusive prevalence." The combination is, at best, debatable in vulcanology, where strombolian and effusive do not always coexist in the same definition. "Either they didn't know how to describe the phenomenon, or they resorted to a type of eruption with scarce scientific precedent," noted an analyst.

By the end of 2021, the figures were consolidated: 85 days, 215 million cubic meters. The lava reached the sea, forming a new delta. The airport closed and peine several times. And in December, the volcano finally fell silent.

What Came After: The System Remains Active

What many treated as a happy ending was, in reality, a comma. In March 2022, the seismic network detected a "small uptick" in La Palma. According to the tracked data, magma continued to migrate at depth, refilling the void left by the eruption. In July, the seismic swarm shifted to Teide, with over 630 hybrid events detected by Involcan in just a few hours, all of small magnitude and located between 9 and 12 kilometers deep. In September, a new reactivation refocused attention: noises, unbreathable bluish SO2 gases throughout the Aridane Valley, and residents feeling tremors in their homes.

A study published in Scientific Reports — authored by Involcan, the University of Granada, and the Trofimuk Institute of Novosibirsk — estimated the reserve of partially molten magma beneath La Palma at 400 cubic kilometers, situated between 7 and 25 kilometers deep. This is a conservative estimate. In other words: what emerged in 2021, monumental as it seemed, is merely an insignificant fraction of what remains below.

And here's the startling fact: the 215 million cubic meters expelled by the volcano in 85 days is equivalent to 0.215 cubic kilometers. The reserve beneath the island is estimated at 400 cubic kilometers. Therefore, what devastated 1,500 homes, buried Todoque, and created a new delta is less than one-thousandth of what lies beneath. No one knows when it will rise again, but the system remains active.

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Trinc the complete analysis, with lava flow maps, press conference transcripts, and satellite images, in the original source.