La Palma volcano: how satellite imagery helps us understand the eruption

More than a week after the eruption of Cumbre Vieja, satellite imagery has helped authorities control and manage the crisis.

From measuring gas emissions to assessing damage, the Sentinel satellites of the European Copernicus network provide critical data.

Emergency management service Copernicus provided daily maps to monitor the lava flow and estimate the number of damaged objects. On Wednesday, it was revealed that the molten rock had destroyed 656 homes and stretched over an area of ​​267 acres.

The Sentinel 5 satellite is capable of detecting emissions of nitrogen dioxide (SO2) into the atmosphere. Emissions reached Italy on Sunday. The plume is much larger, but much of the ADAM image is obscured by clouds.

And by blending satellite data and meteorological models, the Copernicus Atmospheric Monitoring Service can predict the evolution of a SO2 plume that will reach the Arctic Ocean through southern Spain, Italy and the Balkans in the coming days before heading into the Atlantic Ocean. Despite the startling concentrations reported on the Windy.com app, scientists agree that these concentrations are not harmful to health or the environment. They remain at an altitude of 5000-10000 meters and will not have much effect on air quality or acid rain.

The satellites also give a clearer picture of the eruption area. Iban Ameztoy, an expert on Earth observation tools, creates animations that allow you to “fly” over the terrain. The Copernicus Sentinel 2 satellite captured one of the first cloudless images of part of a large lava flow over the weekend. The NASA/USGS Landsat 8 satellite then captured the entire scene.

Last week it seemed that the Sicilian Etna, the most active volcano in Europe, was a little jealous of its Canarian neighbor and again new episode of explosive activity also spotted by satellites.

Satellite imagery is not an exact and predictable science. Getting good pictures is highly dependent on weather conditions, and Earth observation satellites only fly over a given location once every couple of days.

Another key to the success of satellite imagery is the way the images are acquired and processed. Experts apply special filters to highlight aspects such as humidity or, in this case, to better see the lava flow.

Each satellite has its own specifics. Sentinel 2 satellites are the most powerful in terms of optical capabilities.

Sometimes these impressive images can also lead to misinterpretation. Last week, when the Atmospheric Monitoring Service showed emissions of sulfur dioxide from the volcano, many were quick to “warn” about a possible SO2 “cloud” that would affect Europe. Scientists had to explain that these emissions remain in the upper atmosphere and do not affect air quality. The gases from the La Palma volcano are certainly less harmful than the SO2 we get from burning fossil fuels.

Satellite imagery also allows you to simply contemplate the overwhelming power and terrifying beauty of this natural phenomenon from a different, almost surreal angle.