Modelling of a submarine landslide in the Svalbard Islands indicates that tsunami waves could be more than 4 meters high and reach the coast in 50 minutes.
A new study with the participation of the Institut de Ciències del Mar (ICM-CSIC) has concluded that submarine landslides triggered by global warming in the area of the Svalbard Islands (Norway) could generate tsunamis. The formation of tsunami waves would be controlled by the development of the submarine landslide and its impact by the topography of the seabed and the coast. The results of this work show the need to continue investigating glacial margin instability in future climate scenarios due to the important impact on coastal infrastructure and populations.
Global warming impacts the Arctic with an increase in ocean water temperature and a decrease in glacier thickness. Both processes give rise to an ideal scenario for the formation of submarine landslides with tsunamigenic potential.
To study this scenario, scientists from the the University of Granada, the Andalusian Institute of Earth Sciences, the Institut de Ciències del Mar of Barcelona (ICM-CSIC) and the University of Malaga analyzed the rupture and displacement dynamics of the ancient Storfjorden LS-1 landslide, located southwest of the Svalbard Islands, between 420 meters and 1900 meters deep, with a length of 60 kilometers, a volume of 40 cubic kilometers hosted in an area of 1300 square kilometers. The landslide has been determined to be tsunamigenic and its modeling demonstrates the formation of tsunami waves of up to 4.3 meters.
"In order to understand the impact of global warming on our planet, it is essential to know the geological processes of the past. Modeling of ancient submarine landslides is relevant as it provides us with information about geological hazards in Arctic coastal areas. This study recreates scenarios of tsunami formation due to landslides resulting from global warming that we may face in the future," says researcher Mayte Pedrosa, a researcher at the University of Granada.
The propagation of these waves is determined by the presence of glacial grooves of hundreds of kilometers that were excavated by Quaternary glaciers on the seafloor. Their morphologies condition the amplitude, amplification and diffraction of the tsunami waves, as well as the time of impact on the coasts of the Svalbard Islands.
"This research is important because the results have social and economic impact. Geological hazards such as submarine landslides and tsunamis affect coastal communities and the activity of different marine and coastal economic sectors," confirms Gemma Ercilla, from the ICM-CSIC.
"The results of this study will help the competent authorities and agencies to develop appropriate mitigation plans to manage the impact of tsunamis. The next steps of the research involve studies focused on the relationship between different geological risk processes governed by global warming, such as the generation of earthquakes by isostatic readjustment due to ice loss, landslides and the impact of both on the combined generation of tsunamis," concludes Ercilla.