The Lituya Bay Tsunami hit the Gulf of Alaska more than 60 years ago. On July 9, 1958, an earthquake estimated at magnitude 7.7-8.3 triggered a massive landslide or rockslide here, estimated at 40 million cubic yards. The shape of the bay is long and narrow with glaciers entering it in two locations on the landward side, like the top of the letter T. The rockfall hit one of the glaciers and caused a Tsunami that ranup 1,720 feet on the nearest shore, with a wave height in the bay estimated at 50 to 75 feet high! Read more about the event from one of my favorite geo bloggers, David Bressan on Forbes.com.
Source: World’s Tallest Tsunami Hit The Gulf of Alaska More Than 60 Years Ago