In a stunning display of nature's raw power, a colossal landslide in Alaska's Tracy Arm Fjord on August 10, 2025, generated the second-largest tsunami ever documented. The resulting wave surged to an astonishing height of 481 meters, dwarfing the Empire State Building's 443-meter stature. This event, now confirmed by researchers, underscores the escalating impacts of climate change on our planet's fragile landscapes.
The dramatic incident unfolded in the early morning hours at 5:30 AM, a timing that proved fortuitously life-saving. The fjord, a popular tourist destination known for its breathtaking granite walls and glaciers, was devoid of cruise ships or other vessels at that hour. Consequently, no injuries were reported, a remarkable outcome given the tsunami's immense scale.
Scientists have determined the tsunami was triggered by a massive landslide, where approximately 64 million cubic meters of rock collapsed into the fjord in about one minute. This volume is equivalent to 24 times the size of the Great Pyramid of Giza. The confined space of the fjord acted like a funnel, compressing the displaced water and propelling the wave to its record-breaking height.
The landslide itself was directly linked to climate change. The glacier that had once stabilized the mountainside had receded due to rising global temperatures, leaving the rock unsupported and prone to collapse. This event serves as a stark warning of the increasing frequency of such climate-induced geological hazards.
Researchers reconstructed the event using aerial photography, satellite and seismic data, fieldwork, and eyewitness accounts, as no direct video or photographic evidence existed. The tsunami's passage left a vivid scar on the fjord's walls, stripping vegetation up to the 481-meter mark and creating a stark, visible line between the damaged lower slopes and the pristine forest above.
The seismic waves generated by the collapse were detected worldwide, and the event also triggered a 'seiche'—a prolonged oscillation of water within the fjord that lasted for several days. This phenomenon is similar to one observed after a 2023 landslide-triggered tsunami in Greenland's Dickson Fjord, which produced a 200-meter wave.
While the 1958 tsunami in Alaska's Lituya Bay remains the largest ever recorded at approximately 520 meters, the Tracy Arm event now holds the second-place title. Researchers noted that seismic data revealed small earthquakes in the week preceding the landslide, offering a potential avenue for developing early warning systems for future events. "The fact that the landslide occurred so early in the morning was incredibly lucky. Next time—and there will be a next time—we may not be so fortunate," cautioned geomorphologist Dan Shugar.
Based on reporting from g1.