Assertion: wave's movement | /r/Causes | displacement of the seabed
Facets:
Source sentences:
text: Movement on normal (extensional) faults can also cause displacement of the seabed, but only the largest of such events (typically related to flexure in the outer trench swell) cause enough displacement to give rise to a significant tsunami, such as the 1977 Sumba and 1933 Sanriku events.