Asked in Tsunamis

What was the biggest tsunami ever recorded?


Wiki User

This depends on what is meant by "biggest".

Largest/highest tsunami

The largest tsunami ever recorded occurred on 9 July 1958 in Lituya Bay, Alaska. An earthquake measuring 8.3 on the Richter scale shook loose around 40 million cubic yards of dirt and glacier from a mountainside at the head of the Bay, resulting in a tsunami, or series of waves. Although the only witnesses to the event were a couple of fishing boats, the height was able to be determined by scientists finding the high water mark, where the water reached its highest point on the nearby land. This massive tsunami reached a height of 524 metres, or over half a kilometre, the equivalent of 1,720 feet or 40 feet short of a third of a mile. This is twice the size of the Eiffel Tower.

Although the hillsides in the bay were devastated, the damage was very localised and minimal, as Lituya Bay is very remote, there were very few casualties. The Lituya Bay tsunami was labeled a mega-tsunami, but its damage was relatively small because the area is so remote. It was fortunate that the area was uninhabited, or else the effects could have been even more devastating. As it was, two people died when their fishing boat sank when it was hit by the tsunami.

Higher tsunamis are believed to have occurred without human witnesses, so their heights have not been recorded.

Most devastating tsunami

Not the largest, but the most devastating tsunami ever recorded was the Boxing Day 2004 tsunami. The Sumatra-Andaman earthquake on 26 December 2004 resulted in an earthquake with the magnitude of 9.3 occurring on the ocean floor near the west coast of Sumatra, perhaps the most devastating tsunami ever recorded, the height of the wave was only about 100 feet, far from the largest. Over 230,000 people were killed. The impact of this earthquake affected the time of the Earth's rotation time and It caused the entire planet to vibrate as much as 1 cm (0.4 inches).