While earthquakes are the most common cause of tsunamis, the waves are generated by any phenomenon which rapidly changes the shape of the sea surface over a large area: volcanic eruption, landslide, even meteorite impact.
(earthquakes; are; the most common cause of tsunamis) (the waves; are generated; by any phenomenon) (any phenomenon; rapidly changes; the shape of the sea surface; L:over a large area)
earthquakes the waves any phenomenon
are are generated rapidly changes
the most common cause of tsunamis
by any phenomenon
the shape of the sea surface L:over a large area