Detecting Coastal Pumice From The Submarine Volcanic Eruption By Using High-Resolution Satellite Images.

In August 2021, a submarine volcano erupted in Ogasawara islands which are located in Japan. As a result, a large amount of pumice have drifted to Okinawa, 1000 kilometers away from the islands. The pumice existence is a severe problem because they greatly influence not only industries such as fisheries and tourism, bus also the environment. Therefore, monitoring pumice is important. In this study, we acquired bi-temporal high-resolution satellite images of Okinawa coastlines before and after the arrival of pumice, and took corresponding drone images for cross-check. To detect the pumice, we built a binary semantic segmentation model. The prediction result on beaches with pumice arrival was like the figures in an attached image. They had enough high accuracy and implied that the model can be applied to time-series monitoring in the future.