Climate change is preconditioning large landslides in polar and alpine regions. Tsunamigenic landslides have occurred recently in Greenland (Kalaallit Nunaat), but none are known from the east coast. In September 2023, we observed an unprecedented global 9-day-long 10.88 mHz (92 s) monochromatic very-long period (VLP) seismic signal, originating from East Greenland. We demonstrate how 25 M m3 of rock detached from a mountain and entered Dickson Fjord, triggering a 200 m high tsunami. Simulations show that the tsunami stabilized into a 5 m high seiche with a frequency similar to the VLP seismic signal, coupling with the solid Earth as surface waves. However, the extremely low attenuation of the seismic signal remains enigmatic. Ongoing warming will increase the societal risk posed by these events.
These results are submitted for publication and are currently in review.
This repository contains codes used in our analysis and information required to prepare the figures in the manuscript and supplementary material.
The repository follows the structure of the manuscript, where codes and/or instructions and data sources are provided for each figure and its subplots:
fig1\: Seismic source, tsunami observations and modeling.
fig2\: Landslide observations
fig3\: Landslide seismic signal and modelling
fig4\: Very-Long-Period (VLP) seismic signal characteristics
supplementary\: Figures in the supplementary materials.