The slope above the bay was covered in spruce trees that had stood for centuries. After the water went up it, every one of them was gone. The bare line ran 524 metres above the bay.
Mikhail Nosov, an oceanologist who studies tsunamis, had just spent several minutes taking apart a favourite story: waves from falling space rocks. They happened in Earth's deep past, he said. In all of recorded history there is not one in the tsunami catalogues, among some 3,000 events. Models with waves kilometres high are popular, in his view, because they are good for scaring the public.
Then the host asked for a confirmed case, something real. His answer was short: why go to the distant past? Lituya Bay, Alaska. No comet, no asteroid. And the largest tsunami wave anyone has ever recorded did not cross an ocean or begin with an earthquake. It began as a rockfall into a bay.
Lituya Bay sits on the Pacific coast of Alaska, about 100 miles southeast of Yakutat, according to the University of Alaska Fairbanks Geophysical Institute in 2025. The Institute calls it the site of the largest splash wave ever recorded. In July 1958 a huge mass of ice and rock dropped into the water. The bay is deep and narrow, much like a fjord, so the water had nowhere to spread. It climbed the opposite slope instead.
That is the recorded figure, 524 metres, caused by a landslide in the bay.
Это зарегистрированная величина, 524 метра, вызвано оползнем в бухте.
— Mikhail Nosov, Osnova, 22:17
For scale, Nosov offers two buildings. The wave stood taller than the Eiffel Tower and about twice the height of the spire of Moscow University. The host's reaction in the recording is one word: "What?"
Along the shores of the bay the damage was more modest, a few hundred metres in places and a few tens in others. It still left a mark you can see from the air. In the aerial photographs of the aftermath, the coastal strip is cleared of forest, like a shaved stripe around the water's edge.
Then comes the detail that makes you look at the map again. Events of this kind happen in that bay "with enviable regularity". The host cut in: "Or unenviable." Nosov agreed, in effect, and added that not long ago there was another one, only a little smaller, in the same part of Alaska, with a wave of about 400 metres. He could not name the exact place. A University of Oxford release in May 2026 describes a second-largest megatsunami in an Alaska fjord. More than 60 million cubic metres of rock fell into the water, and the wave ran 481 metres up the fjord wall.
So the champion of the catalogue is not a monster from the open sea. It is a steep wall of rock and ice above deep, narrow water, and the same kind of place keeps doing it again.
