Eruption on a volcanic island
Background
In the autumn of 2021, the island of La Palma, part of the Spanish Canary archipelago off the coast of West Africa, saw a spectacular volcanic eruption.
On September 19th, the Cumbre Vieja volcano, dormant for decades, erupted violently. In a devastating spectacle it unleashed ash and molten lava. Rivers of red-hot lava flew down the volcano’s slopes, engulfing homes, farms, and roads. Although the eruption did not claim any lives, the total damage was huge. It was estimated at over 800 million Euros, including the destruction of infrastructure, residential areas, and agriculture. More than 2,800 buildings were destroyed.
La Palma heavily relies on tourism, which suffered a severe blow as the island’s natural beauty was temporarily overshadowed by the eruption. Tourism revenue plummeted by approximately 60%, temporarily causing significant job losses and business closures. Additionally, the destruction of farmland and infrastructure disrupted the island’s agricultural and transportation sectors.
Local authorities acted swiftly, evacuating thousands to ensure their safety. Using among others satellite data, scientists closely monitored the eruption’s progression, providing essential data for informed decision-making.
Exercises
- Satellite Map:
- Look at the satellite image maps and click on the layer selector in the upper right. Deselect all layers and layer groups by unticking the respective boxes.
- Use the overview satellite images in true colour only, and compare those from August (before the eruption of the volcano), October (during eruption) and December 2021 (after eruption).
- Now use the false-colour “urban” infrared images. Do they give different information than the true colour images? Look e.g. to the lava flows (even in the December image hot spots can be seen in the lava).
- Next use the layer group “Detail” and compare the true colour images (note: the true colour images have been mixed with infrared bands to highlight the hot lava flow). What changes are caused by the eruption and the lava flow?
- Zoom to the lava field and add the layer “lava”, which has been derived from the December image. Deselect the December image and display the August image and the lava layer only. This allows to highlight the impact of the lava flow (destruction of settlements and fields, change in the coastline).
- EO Browser:
- Open the EO Browser.
- Find the most recent Sentinel-2 dataset covering the area displayed in the satellite map. Is it easy to find (more or less) cloud-free images? Why/why not?
- Select a true colour visualisation.
- Can you identify additional, recent changes in the area (check e.g. new vegetation on the lava field, reconstruction work)?
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