A paleotsunami is a tsunami that occurs prior to written history where there are no documented observations.[1] Paleotsunamis are evidenced by modern technology and scientific research. One of the largest was a megatsunami resulting from the asteroid that wiped out the dinosaurs.[2]
Studying paleotsunamis is an emerging science to identify and interpret paleotsunami deposits.[3] There are several recorded paleotsunami records, but though some are known only by historical mentions, such as tsunamis resulting from the 1700 Cascadia earthquake which is known only from oral traditions among the Native Americans of the Pacific Northwest.