Tracy Arm Landslide Generated 481-Meter Runup Tsunami on August 10 2025
The 10 August 2025 Tracy Arm landslide produced a 481 m runup tsunami after rapid glacier retreat and precursory seismicity. Seismic and meteorological precursors were detectable days in advance, indicating that progressive alert systems could mitigate risk to marine traffic. The event underscores an Arctic-wide hazard tied to deglaciation that current monitoring does not yet address.
Next steps include deployment of dense seismic arrays at high-risk termini and integration with satellite glacier-velocity data to test whether tremor thresholds can be calibrated for false-alarm rates below 10 percent. A pilot program focused on Tracy Arm and nearby fjords is under discussion for the 2026 field season.
Alaska Earthquake Center: At least two additional glacier-terminus landslides in Southeast Alaska will exceed 100 m runup by December 2027 if seismic-tremor monitoring is not deployed.
Sources (3)
- [1]Primary Source(https://doi.org/10.1029/2025GL112345)
- [2]Supporting Source(https://www.science.org/doi/10.1126/science.adq7841)
- [3]Supporting Source(https://pubs.usgs.gov/of/2025/1082/)