In News:

Massive Greenland landslide sent seismic waves around earth for 9 days. One year ago, roughly 25 million cubic metres of ice and rock splashed into the Dickson Fjord in Greenland and displaced the water enough to give rise to a 200-metre high mega-tsunami; in this way, a melting glacier led to a planet-wide tremor, and researchers warn that it may not be the last

Seismic Observations

• Detection: Unusual seismic signals recorded by stations worldwide, characterized by a single frequency, unlike typical earthquake vibrations.
• Classification: Initially termed a "USO" (unidentified seismic object) due to its atypical properties.
• Duration: Waves persisted for nine days, unlike typical aftershock patterns.

Investigation Efforts

• Collaboration: Involved over 68 researchers from 40 universities across 15 countries.
• Data Sources: Combined seismic data, satellite imagery, water level monitors, and a classified bathymetric map from the Danish Navy.
• Conclusion: The seismic waves resulted from a massive landslide caused by the collapse of Hvide Støvhorn peak, which triggered a series of events leading to the tsunami.

Mega-Tsunami and Seiche

• Tsunami Details:
  • Created by the avalanche crashing into the fjord, displacing water significantly.
  • Resulted in waves that reflected off fjord walls, reaching heights of nearly 110 meters due to the fjord's unique shape.
• Seiche Phenomenon:
  • Oscillations in the fjord persisted for over nine days, reflecting the energy from the landslide.
  • Maximum amplitude of the seiche recorded at 7.4 meters, with a frequency of 11.45 MHz.

Climate Context

• Global Warming Impact: Thinning glaciers contributed to instability in the region, making such landslides more likely.
• Future Predictions: Researchers warn of increased frequency and scale of similar events as climate change continues to affect Arctic and subarctic regions.

Key Takeaways

• The Greenland landslide serves as a reminder of the unpredictable consequences of climate change, including massive geological events.
• The incident highlights the interconnectedness of natural systems and the potential for localized events to have global repercussions.