Overview
- A Science study released Wednesday reconstructs the August 2025 Tracy Arm collapse and confirms a 481 meter runup, the second highest ever recorded.
- About 64 million cubic meters of rock fell in roughly one minute, producing long-period seismic waves equivalent to magnitude 5.4 and a prolonged fjord seiche.
- The slide hit around 5:26 a.m., and the early hour spared cruise ships, though campers and boaters reported strong currents and gear swept away.
- Scientists tie the failure to rapid retreat of South Sawyer Glacier that removed ice support from the slope, and they identify tiny precursor quakes that could guide alerts.
- There is no operational warning system for these landslide tsunamis, and at least six cruise lines have already removed Tracy Arm from 2026 itineraries.