DETECTION OF 200-METRE TSUNAMI IN GREENLAND BY SLOVENIAN SEISMIC STATIONS

Abstract

Tsunamis are natural disasters which can create unimaginable havoc, as was the case in 2004 in the Indian Ocean. They are not necessarily triggered by strong earthquakes; their source can also be a landslide, meteor fall, volcanic eruption or other event which causes large amounts of material to be displaced in a body of water, causing a large water wave to travel outward. On September 16th 2023, at around 1 PM UTC, a very narrow, atypical seismic signal was recorded by the Seismic Network of the Republic of Slovenia, with a wave period of 92 s and a slowly decreasing amplitude which could be observed for more than six days. We estimated the waves were arriving from a N-NW direction and to our surprise were recorded by most broadband seismic stations over a very large area, up to several thousand kilometres from the suspected origin. A deeper analysis of the seismograms revealed that this very monochromatic wave had originated in a coastal area of SE Greenland, but not much more could be discovered at that point. After about a year an article was published in Science magazine, discussing an event in Dickson Fjord in SE Greenland which had been analysed by a large international multidisciplinary group of scientists, which was found to have been a tsunami and seiche in the fjord triggered by a large landslide.