Paleotsunami

On the coast of Chile, boulders have been found that "suggest directionality from sea to land," and they "could not be transported by rolling.

"[4] On the northern Chilean coast, probable evidence of a tsunami exist as one boulder on the sand high above the Pacific can be found, dwarfing every other rock in view in a conspicuous manner.

[5] A tsunami struck in AD 1076 in southern China, during the Song dynasty and nearly wiped out civilization in what is now Guangdong.

[11] The Indigenous peoples of the Pacific Northwest Coast carried the story on in many oral traditions,[12] though they left no written records.

From historical records, there were three large tsunamis dating back as far as the 17th century, some producing waves dozens of meters high.

However, the Japanese based many of their tsunami-defense preparations on smaller tsunamis that had previously hit Japan.

In 2011, tsunamis destroyed entire cities, crippling the Fukushima Daiichi Nuclear Power Plant.

[28] Near where Viking I landed were many boulders, possible debris from a megatsunami, which may have struck perhaps 3.4 billion years ago.

[29] What happened was possible via two different scenarios, one caused by a 5.6 miles (9.0 km) asteroid meeting "strong ground resistance," releasing 13 million megatons of TNT energy, or a 1.8 miles (2.9 km) asteroid hitting the softer ground, releasing 0.5 million megatons of TNT energy.