Landslide, tsunami, seiche in Tracy Arm fjord, Alaska - 10 August 2025

[Astronuc]

On August 10, 2025, there was a massive landslide on the eastern side of Tracy Arm fjord. Although some sources mention 1000 ft tsunami, that height represents the run-up on the sides of the fjord. Technically it was a seiche.

n August 10th, a more than 1,000 foot high megatsunami was generated 59 miles southeast of the city of Juneau within Alaska. While the worst of this wave was completely confined to the Tracy Arm (fjord), evidence shows that the seiche from this landslide generated megatsunami continued sloshing back and forth across a 1,100 meter stretch of water for nearly 35 hours. Do note that this did not cause 1,000 feet or more of run-up for this entire 35 hour long duration.

Early View of Tracy Arm Landslide Features​

Tsunami-causing slide was largest in decade, earthquake center finds​

https://www.gi.alaska.edu/news/tsunami-causing-slide-was-largest-decade-earthquake-center-finds


https://alaskapublic.org/news/envir...tsunami-rip-through-tracy-arm-south-of-juneau

 

[sbrothy]

Wow. You have a knack for finding these, huh? Good thing young people with climate-angst aren’t following you. They’d have a nervous breakdown!

In my youth is was The Bomb. For todays youth it’s The Climate.

 

[ShadowKraz]

Wow. You have a knack for finding these, huh? Good thing young people with climate-angst aren’t following you. They’d have a nervous breakdown!

In my youth is was The Bomb. For todays youth it’s The Climate.

And getting under a desk is just as helpful for both.

 

[sbrothy]

And getting under a desk is just as helpful for both.

Hah yeah: "Duck and cover!"

 

[Astronuc]

Alaska's 1,578-foot tsunami was second largest ever recorded​

https://www.usatoday.com/story/news...i-highest-record-largest-history/89961944007/

Researchers have concluded that a 2025 tsunami in Alaska was the second largest recorded natural disaster of its kind in history, with a wave that reached up to 1,578 feet high.

The massive tsunami took place at 5:26 a.m. local time on Aug. 10 in the Tracy Arm Fjord, a popular cruise destination about 50 miles south of the state's capital, Juneau. As defined by National Geographic, a fjord is a long, narrow body of water that reaches far inland, often lined by a steep walls of rock.

No injuries were reported, but the tsunami stripped vegetation from steep rock lining the near 25 mile-long fjord with cliffs stretching more than 3,280 feet high, according to Dan Shugar, lead author of the study published May 6 in the journal Science.

 

[Zaciekawiony]

Similar risk is possible in Norway in fiords.
https://www.lifeinnorway.net/tafjord-tsunami/