Avalanche in Tracy Arm, Alaska in August 2025 triggers second highest tsunami in recorded history [View all]

Tracy Arm fjord tsunami in popular Alaskan cruise spot provides valuable lessons.

The Tracy Arm fjord is about 30 miles long, named after Benjamin Franklin Tracy, Secretary of the Navy from 1889 through 1893

UCalgary scientist Dan Shugar lead author of study published in the journal Science on megatsunami more than twice height of the Calgary Tower

https://ucalgary.ca/news/tracy-arm-fjord-tsunami-popular-alaskan-cruise-spot-provides-valuable-lessons

When part of a mountain in southeast Alaska slid into the ocean last summer, it triggered the second-highest tsunami ever recorded.

The tsunami on Aug. 10, 2025, ran 481 metres — two-and-a-half times the height of the Calgary Tower — up the wall of the Tracy Arm Fjord more than a kilometre away and generated a seismic signal equivalent to a magnitude 5.4 earthquake.

Despite its massive size, no one was caught in the wave because it hit around 5:30 a.m.