On 22 December 2018, a tsunami that followed an eruption and partial collapse of the Anak Krakatau volcano in the Sunda Strait struck several coastal regions of Banten in Java and Lampung in Sumatra, Indonesia. The tsunami was caused by an undersea landslide that followed an eruption of Anak Krakatau, the “Child of Krakatoa”. On 23 December, it was found that much of the island of Anak Krakatau had collapsed into the sea.
The first tweet shows the changes in the volcano just over one one month.
The second shows the neighboring islands some of which have had the coastline scoured by the tidal wave.