Measuring last year’s outbreak in the Canary Islands

one of the The most damaging volcanic eruptions From 2021 the event was a day no Palma in the Canary Islands. The The explosion lasted for several months And it ended up Buried a large part of the communities built on its slopes. Fortunately, it was an eruption that didn’t end up taking lives, but as much damage At least 1 billion dollars. As it turned out, the eruption itself compared to the others was relatively small, but the human impact was much greater.

a A new study in Nature by Ricardo Civico Others have given us high-resolution digital elevation models (DEMs) for the La Palma eruption. These models were created from over 12,000 images to create a map with a resolution of 0.2 mm per pixel (below). That’s 0.007 inches per pixel, or roughly the size of two sheets of paper stacked together on the edge. Now that’s high resolution! This data means that we can really measure what happened. The lava flows and volcanic debris from the new cone that formed on the volcano turned out to be more than impressive.

High resolution Diem for the 2021 La Palma eruption. Credit: Civico et al. (2022) in Nature/INVOLCAN.

Putting a scale on the lava

Over the course of 85 days, the area on the Cumbre Vieja fault in La Palma experienced an influx of more than 7 billion cubic feet (0.2 cubic km) of lava and debris. Although that sounds like a lot, it’s 1/7 the size of a file 2018 KILaoya eruption and 1/5 the size 2014-15 eruption of Holuhraun in Iceland. The historical eruption that was very close to the same range as La Palma was the famous 1943-1952 Paricotin eruption in Mexico. All of these eruptions are good comparisons because they created very similar types of lava in similar patterns.

The volcanic cone built during the eruption (see above) had a volume of 1.3 billion cubic feet. To put that in some perspective, this is roughly equal to 15 pyramids of Giza. Not too shabby for 3 months of volcanic activity. All of this was happening at an eruption rate of 700-1700 cubic feet per second (20-50 cubic meters per second). This is something that exists 66-166 tons (60,000-150,000 kilograms) of lava and debris coming out of the vents per second!

It’s hard to put these kinds of numbers into any context we’re familiar with in our daily lives. However, in terms of volcanic eruptions, they are really not out of the ordinary. Volcanic activity is just that strong on our planet! Even what’s considered a fairly small to medium-sized explosion – ranking third in the volcanic eruption indicator – It looks amazing.

very runny lava

Lava flow map of the 2021 La Palma eruption, using elevation change as a proxy for new lava flow deposits. Credit: Civeco et al. (2022) in Nature.

It turns out that a file Chemical properties of magma It also helped them flow so far and fast. The lava itself was rich in alkaline elements such as sodium and potassium – a lava called bassinet. This type of lava is similar to basalt (the material that erupts in Hawaii) but is less viscous (viscous), so it can flow faster and farther than its Hawaiian counterpart.

Currently, Cumbre Viejo in La Palma is relatively calm as was the eruption Announced December 2021. There were sometimes swarms of earthquakes and The ground under parts of the new cone is still glowing With cooling lava heat. Perhaps La Palma will go back to sleep for 50 years as it did after the 1971 eruption. Perhaps it will start reappearing this year. We don’t know (and anyone who says otherwise is selling something). Volcanologists will continue to monitor the volcano for signs of possible disturbances on the island volcano in the Atlantic Ocean.