A massive eruption of the Cumbre Vieja volcano on the northeast Atlantic island of La Palma has spurred evacuations, injected gases and ash high into the sky, and brought about an explosive social media firestorm.

La Palma is in the Canary Islands, a part of Spain, and is home to more than 80,000 people. The volcanic eruption is the Canary Islands’ first volcanic eruption on land in 50 years.

At least 5,000 people have been evacuated from vulnerable parts of the island, and several neighborhoods have already succumbed to surging lava.

On Sept. 11, an earthquake swarm began rocking the volcano, foreshadowing an ominous development to come. Authorities issued a yellow alert for part of the island on Sept. 13, the second-highest tier of advisory that can be issued for an imminent or expected eruption. According to Spanish newspaper El País, about 35,000 people were included in the alert.

The eruption began on the afternoon of Sept. 19 in the area of Cabeza de Vaca near the Las Manchas district southwest of the volcano in the mountains. The Canary Islands Security and Emergency office has a level 4 out of 4 red “emergency” warning up still; on Friday, it warned of an “intensification of the explosive phenomenon,” along with an “increase in the reach of pyroclastic material” and “intense ash emission.”

New evacuation orders were hoisted during the midafternoon for Tajuya, Tacande de Abajo and the non-evacuated part of Tacande de Arriba; evacuees were asked to go to the El Paso soccer field.

Authorities closed the airport in La Palma on Sept. 25 as ash from the erupting volcano spread across the Spanish island. (Reuters)

Authorities cautioned that the volcano’s edifice was becoming increasingly unstable, and that those in the evacuation zones may experience large vibrations, detonations or the arrival of materials at high temperature.

“Stay calm,” emphasized the island’s volcano monitoring agency. “One should not carry themselves with panic.”

There have been 1,130 earthquakes in the last week, the greatest of which had a magnitude of 3.7; most have occurred within about four miles below the surface.

Sulfur dioxide spewing into the atmosphere

Volcanoes inject plentiful gases into the upper atmosphere; some models indicate that material is being swept over Europe, but experts have expressed concern that the models may be overestimating how much has been released. Sulfur dioxide is harmful to humans near the surface. The International Volcano Health Hazard Network states that “short-term overexposure causes inflammation and irritation, resulting in burning of the eyes, coughing, difficulty in breathing and a feeling of chest tightness.”

“Based on satellite observations of SO2, so far most of the SO2 emissions from La Palma have remained in the vicinity of the Canary Islands and the island of Madeira to the north,” wrote Simon Carn, a volcanologist at Michigan Tech, in an email. “We might expect some local impacts such as haze, poor air quality and perhaps acid rain on La Palma or neighboring islands.”

He noted that, while impacts have been localized, they could extend farther downwind if the eruption becomes more vigorous.

“In any case, we certainly don’t expect any larger-scale impacts of this type of eruption (e.g., on climate),” he wrote. “If the active lava flows reach the ocean, we could see the formation of ‘laze’ plumes that are generated when hot lava boils seawater, producing an acidic plume rich in HCl (hydrochloric acid) and lava fragments. These can be locally hazardous downwind.”

Other gases emanating from the volcano could also be hazardous, but only near the crater.

Hydrogen sulfide, for instance, smells of rotten eggs and is toxic. High concentrations can paralyze the respiratory system, causing breathing to stop. During the 1971 eruption of Teneguía on La Palma, a photographer was asphyxiated by poisonous gases.

Lava engulfing homes and neighborhoods

Images shared on social media obtained from overhead depict lava flows extending into valleys surrounding the volcano. Officials note that 234 structures have been affected.

Lava can boast temperatures close to 2,000 degrees, instantaneously melting, scorching or igniting anything it comes into contact with. Drone footage captured the moments lava poured into a swimming pool, vaporizing the water.

Copernicus Emergency Management Services used radar data to map where lava flows had reached so far; they estimate nearly 400 buildings have been destroyed, including 40 that were wrecked on Thursday. Their findings also suggested the lava flow covered about 445 acres.

There’s no way to know exactly how much longer the eruption will persist. Fortunately, it appears the vertical plume hasn’t been tall enough to carry materials to other continents or violent enough to trigger lightning, but officials are monitoring it around-the-clock.

Check out these other remarkable images from La Palma: