Deadly Indonesian tsunami was not caused by an earthquake

A tsunami can also be caused by other things that move vast amounts of water, from storms to underwater landslides, which experts think is the most likely explanation for what happened in the Sunda Strait.

“Anything that rapidly displaces water can cause a tsunami, whether or not it also shakes the ground. The fact that there was no major earthquake means that whatever caused the tsunami near Krakatau put most of its energy into the water rather than into the ground. This would be the case for a submarine landslide.“ Jackie Caplan-Auerbach, a geophysicist at Western Washington University, told The Verge in an email.