Scientists have confirmed a landslide in Greenland triggered a massive seiche, a standing wave, detected by NASA's SWOT satellite. This discovery, published in Nature Communications, resolved a nine-day seismic mystery from 2023. The landslide, caused by a megatsunami in Dickson Fjord, generated powerful waves that sloshed back and forth within the fjord's ice-bound enclosure.

Previous satellite altimeters missed this signal due to observation gaps and limited resolution. SWOT's KaRIn instrument, operating during its critical Science phase, captured high-resolution data showing the seiche's slow decay. Weather reconstructions ruled out other causes, proving the seismic pulses were directly linked to the landslide's tsunami aftermath.

This breakthrough demonstrates SWOT's transformative potential for monitoring oceanic processes in previously inaccessible regions like fjords.