October 27, 1936 Tsunami: Lituya Bay, AK, United States

A localized event of uncertain origin produced three massive waves -- up to 150 m in height -- followed by a series of smaller waves in Lituya Bay. Possible explanations include a subaerial or submarine landslide, the breaching of a glacial lake, glacial calving, or the sudden surge of a glacier into the bay. The lack of evidence for a subaerial source suggests the waves resulted from a submarine landslide. Two small buildings were destroyed, three square km of land were inundated, many trees were uprooted, and 50 barrels of salted salmon washed away. (Ref #239) Four witnesses were situated in the Bay: two in a little house on the western side of Cenotaph Island and two on a small ship riding at anchor off the northern shore of the bay, near Fish Lake Island and 2 km west of the above-mentioned little house. According to the fishermen, at approximately 6:20, a dull, continuous rumbling was heard on board the ship. It appeared to come from the mountains located beyond the top of the bay. Because of the darkness, one could not make out what was happening. No tremors were felt. It was flood time. The rumbling lasted approximately until 6:50, when the first large wave appeared in the narrowest part of the bay. It was like a steep watery wall, stretching from shore to shore and having a possible height of 30 m. Espying this wave, the fishermen weighed anchor and headed for Cenotaph Island. When the wave reached them 10 minutes later, they were situated 400 m northwest of Cenotaph Island, at a depth of 20 m. No drop in water level or other anomaly preceded the arrival of the wave. The first wave lifted the ship about 15 m above the normal level. To the north and south, beyond the shelter of the island, the wave may even have been another 15 m higher. Immediately after the passage of this wave, the water surface dropped below the normal level. A boat with a net, riding at anchor off Cenotaph Island at a depth of 14 1/2 m touched bottom. The first wave was followed by a second and third at estimated 2 minute intervals, and each successive wave was larger than the preceding one. After each of these waves, the surface of the water again fell below the normal level. Small waves were observed during the half hour after the passage of the third wave. All the waves were directed towards the exit from the bay. After this, floating tree trunks and pieces of ice appeared around the ship. No surge of water was observed. The fishermen in the little house were awakened at about 7:00 by a noise, like the droning of hundred airplanes flying at low altitude, and found that a wave was approaching their house. Taking to a high safe place, they saw three waves pass the island, growing in height, with a speed of about 20 knots. The maximal height of the waves was estimated at form 45 to 75 m (Reference #415).