Greenland’s 650-foot tsunami leaves a nine-day global seismic footprint

A September 2023 landslide into Greenland’s Dickson Fjord spawned a 650-foot mega-tsunami that roared through a two‑mile fjord and, unusually, set off a global seiche. Seismic sensors worldwide recorded a steady cadence of 92-second pulses for about two weeks, tracing the signal back to the fjord and the landslide-driven wave. Researchers used field measurements, computer modeling, and SWOT satellite data to map the fjord’s geometry and the wave’s behavior, highlight climate‑change–driven glacier melt as a contributing factor, and suggest improved early-warning options for Arctic shipping and communities.