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Schlagwörter:
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Zusammenfassung:
On 16 September 2023, a cascade of events occurred in East Greenland, involving a large tsunami that hit a military unit. Here, we use seismic waveform data recorded on regional to global scales and compare to high‐resolution satellite images to learn about the cascade of events. We find two distinct seismic signals and develop a conceptual and physical model explaining the observations: initially, the high‐energy seismic signals (0.02–0.06 Hz) occurred, followed by an over one‐week‐long monochromatic signal (0.0109 Hz) recorded even at 5000 km distance. Our single force (SF) inversions characterize both an initial rockslide and the one‐week‐long seiche oscillation processes. The rockslide signal is well reproduced by west and downward SF, with an orientation consistent with observations on satellite imagery. The amplitude decay of the week‐long oscillation, stacked at three teleseismic arrays, is fitted with a damped oscillator model. Using a simple analytical model of water seiching in a narrow fjord, we can explain the force direction and frequency consistent with the results from SF inversion.
