A tsunami caused by a landslide in Alaska's Tracy Arm Fjord last August was the second largest ever recorded, according to a new report published in "Science."
After 64 million cubic meters of rock slid from one side of the fjord, the tsunami stripped vegetation as high as 1,578 feet above sea level from the opposite wall. The initial wave was 100 meters high and traveling at a speed of more than 70 meters per second.
The tsunami hit "common vessel viewing areas" within minutes, according to the study.
No cruise ships were sailing the fjord when the landslide occurred at 5:26 a.m. on Aug. 10., but the National Geographic Venture was near the mouth of the fjord with 150 people onboard at the time, according to the "Science" report.
"At this location, the ship's captain described currents and white water near the edges of the fjord, but no obvious wave," it said.
There was an increase in seismic activity at least 24 hours before the landslide.
Cruise lines are sailing the neighboring Endicott Arm Fjord this summer instead of Tracy Arm due to the potential for more rockfall or landslides. The fjords are popular cruise destinations for glacier viewing.
"Here and in similar settings, increased cruise tourism, small-craft traffic, land-based recreation and expanding infrastructure increases the exposure and thus risk associated with these types of cascading events," the study concludes.