Overview

• In September and October 2023, two massive landslides in East Greenland’s Dickson Fjord, driven by glacier thinning, unleashed mega-tsunamis exceeding 200 meters in height.
• The tsunamis became trapped in the narrow fjord and formed seiches that oscillated for days, sending seismic tremors detectable around the world every 90 seconds.
• Conventional observation methods, including a Danish military vessel survey, failed to record the standing waves directly as they rapidly lost height.
• Data from SWOT’s Ka-band Radar Interferometer provided two-dimensional sea-surface height maps showing cross-channel slopes up to two meters, validating the seiche hypothesis.
• Researchers say the findings highlight the importance of advanced satellite monitoring for assessing climate change-driven glacial collapse and associated ocean hazards in remote regions.