There are two Alaska tsunamis..that interest scientists.. A big one thousands of years ago..and a smaller one that occured in the 50's in a bay..It was over 1700 feet high. That one showed scientists that in waves caused by landslides, the maximum height of the wave is about equal to the height of the landslide..That's why the Canary Island scenario is so scary..
Back in 1953 two geologists travelled to a remote bay in Alaska looking for oil. They gradually realised that in the past the bay had been struck by huge waves, and wondered what could have possibly caused them. Five years later, they got their answer. In 1958 there was a landslide, in which a towering cliff collapsed into the bay, creating a wave half a kilometre high, higher than any skyscraper on Earth. The true destructive potential of landslide-generated tsunami, which scientists named "mega-tsunami," suddenly began to be appreciated. If a modest-sized landslide in Alaska could create a wave of this size, what havoc could a really huge landslide cause?
Exact measurements were 1,500 ft. Lituya Bay 1958. Two fishermen killed, two survived when their boat landed 2 and 1/2 miles inland in the top of the trees.