How to Make a Tsunami

This cartoon shows schematically how a subduction earthquake generates a tsunami. The green material is the lithosphere (which is brittle) and the purple-red material is the asthenosphere (which, while still solid, is deformable). The lithosphere is divided into the overriding (continental) plate on the right and the downgoing (oceanic) plate on the left. The overriding plate is locked against the downgoing plate, so as the downgoing plate subducts, the overriding plate is progressively deformed. The front