A significant landslide in Greenland’s Dickson Fjord in September 2023 initiated a tsunami that reverberated worldwide, resulting in seismic activity that lasted over a week.
Recent findings from the international Surface Water and Ocean Topography (SWOT) satellite mission indicate that these tremors endured for nine days. This information provides researchers with valuable insights into the tsunami’s distinct features and far-reaching effects.
SWOT gathered water elevation data in Dickson Fjord on September 17, 2023, just a day after the landslide. By contrasting this data with measurements taken under calm conditions on August 6, scientists identified substantial variations in water levels, as reported by NASA’s Jet Propulsion Laboratory.
Visually represented data indicated that water levels were up to 1.2 meters (4 feet) higher on the north side of the fjord compared to the south. The tsunami was triggered when approximately 25 million cubic meters (880 million cubic feet) of rock and ice fell into the fjord, which is part of a network of waterways along Greenland’s eastern coastline.
According to a study published in Science Journal, the landslide generated a wave reaching about 200 meters (650 feet) in height.
The Dickson Fjord, characterized by its steep cliffs rising over 1,830 meters (6,000 feet) and a depth of roughly 540 meters (1,772 feet), contained the tsunami’s energy. In this restricted area away from the open ocean, the tsunami’s energy couldn’t easily dissipate, causing the wave to oscillate back and forth every 90 seconds for nine days. This oscillation produced tremors detected by seismic instruments located thousands of kilometers away, known as a seiche.
The SWOT mission, which launched from California’s Vandenberg Space Force Base in December 2022, played a crucial role in collecting this data. This mission was a collaborative project led by NASA and the French space agency CNES, with contributions from the Canadian and UK space agencies.