2026/05/06 by Dan H. Shugar, Katherine R. Barnhart, Mira Berdahl +16 · 2 voices · 2 citations
Earth and Planetary Sciences · Environmental Science · #Bathymetry #Climate change #Cruise #Fjord #Geological formations and processes #Landslide #Landslides and related hazards #Seiche #earthquake and tectonic studies
paper · pdf · doi:10.1126/science.aec3187
published in Science 392(6803), eaec3187 (American Association for the Advancement of Science)
openalex publication_date 2026/05/06 · openalex created_date 2026/05/07 · openalex updated_date 2026/08/01
-cubic meter landslide struck Tracy Arm fjord in Alaska. The landslide was preconditioned by glacial retreat caused by climate change. The resulting 481-meter runup megatsunami followed an initial 100-meter-high breaking wave traveling at >70 meters per second. The landslide was preceded by several days of microseismicity, which increased in rate and magnitude until ~1 hour before failure. The landslide produced globally observed long-period seismic waves equivalent in size to a moment magnitude 5.4 earthquake. A long-period (~66 second) global seismic signal, produced by a landslide-induced seiche trapped within the fjord, persisted for up to 36 hours, the second time a days-long seiche had thus been observed. With fjord regions increasingly visited by cruise ships, and climate change making similar events more likely, this unanticipated, near-miss event highlights the growing risk from landslides and tsunamis in coastal environments.