Arctic Landslide Triggers 1,580-Foot Tsunami in Alaska

On August 9, 2025, a mountainside collapsed into Tracy Arm fjord in Alaska, sending water and debris 1,580 feet (481 meters) up the opposite wall — the second-highest tsunami ever recorded. Researchers at the Alaska Earthquake Center say seismic tremors and rapid glacier retreat could have supported a warning system.

• Wave reached 481 meters, higher than Taipei 101, second-highest tsunami on record
• Glacier retreated over a third of a mile in the two months before collapse
• Thousands of small seismic tremors preceded the landslide
• A monitoring system could have issued warnings at least a day in advance