A recent magnitude 7 earthquake struck near the Hubbard Glacier, located on the border between Alaska and Yukon. This seismic event caused significant avalanches and serac collapses, as revealed by fieldwork conducted by the Yukon Geological Survey (YGS).
Impact of the Earthquake on Hubbard Glacier
The earthquake originated near Mt. King George, where notable rockfalls and avalanches could be observed. Although such a strong earthquake could result in mass casualties in populated areas, there were no fatalities due to the remote nature of the region.
Details of the Earthquake
- Magnitude: 7.0 on the Richter scale
- Depth: Approximately 5 km under the surface of the ice
- Location: Hubbard Glacier, spanning roughly 100 km from Mt. Hubbard to Disenchantment Bay
This magnitude suggests a significant ground shift, tenfold stronger than a magnitude 6 earthquake. The event parallels the historic 1906 San Francisco earthquake, which had a magnitude of about 7.9.
Aftershock Patterns and Geological Insights
Following the quake, the YGS identified clusters of aftershocks that were not neatly aligned, complicating the understanding of the fault responsible for the earthquake. Preliminary findings indicate that multiple geological mechanisms may have contributed. These could include tectonic plate interactions or even local icequakes.
Yukon Geological Survey Observations
The YGS reported that one tectonic plate moved two meters relative to another during the earthquake. However, no visible ruptures were found. Dust from rockfalls and evidence of several large-scale avalanches were noted around Mt. King George, with the most damage occurring in that area.
Risks for Mountaineers
This earthquake raises concerns for mountaineers, especially as global temperatures rise and glaciers respond to climate change. The reaction of glaciers to shallow earthquakes poses risks, including increased rockfall and serac hazards.
Call for Collaboration
The YGS has reached out to the mountaineering community for assistance. They seek photographs of Mt. King George taken before the earthquakes to aid in estimating landslide volumes. Mountaineers who can provide such images are encouraged to contact the YGS.
This earthquake highlights the need for ongoing research into the relationship between seismic activity and glacial environments, especially as climate change accelerates glacier melt. Understanding these changes is essential for ensuring safety in mountaineering expeditions.
