Massive Landslide Triggers Unprecedented Nine-Day Tsunami in Greenland

A massive landslide in Greenland’s Dickson Fjord has caused a nine-day-long tsunami that sent seismic waves felt around the globe. Last September, sensors worldwide detected the unusual seismic activity, prompting a global investigation into its origins.

Scientists were able to pin down the location of the tsunami to a remote fjord in East Greenland

The landslide, which involved a mountainside collapsing and dragging glacial ice into the fjord, generated a colossal 200-meter wave. This wave became trapped within the narrow fjord, causing it to slosh back and forth for an extended period, producing continuous vibrations.

The investigation, detailed in the journal Science, was spearheaded by an international team of scientists and the Danish Navy. Dr. Stephen Hicks from UCL, who participated in the research, described the initial signal as an “unidentified seismic object” that repeated every 90 seconds for nine days.

As the investigation progressed, Danish colleagues reported a tsunami in the remote fjord, leading to a collaborative effort. By analyzing seismic data, satellite imagery, and pre- and post-event photographs, researchers pinpointed the source of the disturbance to Dickson Fjord.

The landslide involved approximately 25 million cubic meters of rock, equivalent to 25 Empire State Buildings, crashing into the fjord. This caused a “mega-tsunami” with a wave high enough to leave a visible mark on the glacier.

Source: Wieter Boone, Danish Military

Unlike typical tsunamis, which dissipate quickly in the open ocean, this wave remained trapped in the fjord system. Dr. Hicks explained that the fjord’s complexity prevented the wave from losing its energy, leading to an unprecedented duration of movement.

The event highlights the increasing frequency of such landslides due to climate change. Melting glaciers are destabilizing Greenland’s mountains, making them more susceptible to landslides. Dr. Hicks noted that the thinning glacier could no longer support the mountain, leading to its collapse.

While the Dickson Fjord event occurred in a remote area with no immediate impact on Arctic cruise ships, Dr. Kristian Svennevig from the National Geological Surveys for Denmark and Greenland (GEUS) emphasized the rising trend of giant landslides in the Arctic. This event underscores the necessity for further research into the impacts of climate change on these vulnerable regions.

Dr. Hicks concluded that this incident may represent a new era where climate change effects are felt globally, even beneath the Earth's crust.