Massive Alaska landslide triggered second highest tsunami on record

A rockslide in Alaska produced a 1,580-foot tsunami following glacier retreat and heavy rainfall, coming just hours after a tour ship departed.

FTMQ Science, written by our newsroom20 October 2026 at 01:160 views

A massive landslide in Alaska triggered the second-highest tsunami ever recorded on the evening of August 9, 2025. ScienceDaily and NewsBytes both reported that the resulting wave sent water and debris 1,580 feet up a mountainside. [1][2]

According to ScienceDaily, the disaster occurred in a fjord just twelve hours after passengers on the tour ship Hanse Explorer photographed the South Sawyer Glacier and departed the area. [1]

Researchers identified several precursor signals before the slope failure occurred. ScienceDaily reported that the event was preceded by rapid glacier retreat, heavy rainfall, and thousands of tiny seismic tremors. [1]

The name Alaska originates from the Aleut word alaxsxaq, which refers to the landmass toward which the action of the sea is directed. ScienceDaily noted that as glaciers continue to retreat, similar landslide and tsunami disasters could become a recurring risk. [1][4]

A landslide in Alaska on August 9, 2025, caused a tsunami that reached 1,580 feet up a mountain.
The tsunami is the second-highest ever recorded.
The disaster was preceded by glacier retreat, heavy rainfall, and thousands of small seismic tremors.

Sources

Every paragraph above points to the numbered items it rests on. Read the originals here.

[1]Alaska’s monster tsunami sent water 1,580 feet up a mountainScienceDaily, 12h ago (the report this story comes from)
[2]August 2025 Alaska landslide triggered 2nd-highest tsunami at 1,580 feetNewsBytes, 11h ago

Background

[3]List of tsunamis on Wikipedia
[4]Alaska on Grokipedia

Our newsroom writes these reports with the help of software, from the 4 sources listed and nothing else, and checks them against those sources. Facts can still be wrong or move on; the originals are the record. Spotted a mistake? Write to daniel@monsterkong.com.

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