In late December 2018, a landslide on the island Anak Krakatoa triggered a deadly tsunami in Indonesia. The island (upper left, pre-landslide) lost an estimated 300 meters of height in the landslide, dramatically altering its appearance (upper right; post-landslide). Much of the slide occurred underwater, dumping material into a crater left by the famous 1883 eruption of Krakatoa.
The slide displaced a massive amount of water, creating a tsunami that spread, refracting around nearby islands and reflecting off shorelines in complicated patterns. A new numerical simulation, shown above, models the post-slide tsunami based on terrain data and fluid physics. Its wave predictions match well with the high-water readings from nearby islands. The scientists hope that such models, combined with monitoring, will help save lives should a future eruption trigger more tsunamis.
For a full picture of both the recent Anak Krakatoa eruption and its famous predecessor, check out this video. (Image credits: satellite views before and after landslide – Planet Labs; simulation – S. Ward, source; via BBC News; submitted by Kam-Yung Soh)