When and where can we use land generated or affected by volcanic eruptions on islands?

What is it about?

This may seem a daft question for a geologist to pose as the most obvious answer is "don't". Land on active volcanic islands is at risk from further eruptions and other hazards. However, land for agriculture and other activities is valuable on islands given its limited availability so, at some time in the future, lavas deltas, such as these in Figure 1 created during the 2022 Cumbre Vieja (La Palma, Canaries) eruption, will likely be developed. When such deltas are first emplaced, they are attacked by the sea and erode rapidly. We have found that erosion distances often follow a surprisingly simple equation: w=[(α+1) E_0 t]^(1⁄(α+1)) Where t is time since the end of the eruption and  and E0 are constants. Where we have a lot of data for a site, this represents the slowing down of coastline retreat reasonably well. Coastal erosion leads to a nearshore shallow bank forming, which causes attenuation of waves attacking the cliffs, slowing down the erosion. Varying resistance of cliff materials to erosion and volumes of debris from cliff failure may also influence this slowing erosional trend.

Featured Image

Photo by Marc Szeglat on Unsplash

Photo by Marc Szeglat on Unsplash

Why is it important?

This opens the possibility of being able to predict where the shoreline will be in the future as a result of erosion if we had enough initial data to constrain the curve parameters. This does not constitute advice...