![]() ![]() When the ground rebounds following a glacier’s retreat, tectonic stress is redistributed, effectively unclamping strike-slip faults, such as the Fairweather, making it easier for the two sides to slip past one another. In 1958, a magnitude 7.8 earthquake triggered a rockslide into Southeast Alaska’s Lituya Bay, creating a tsunami that ran 1,700 feet up a mountainside before racing out to sea. Four glaciers enter the bay from northeast. Glaciers such as the Yakutat in Southeast Alaska, shown here, have been melting since the end of the Little Ice Age, influencing earthquakes in the region. ![]() The particular T-shape of Lituya Bay is caused by the Fairweather Fault, crossing the end of the bay from southeast to northwest. While the melting of glaciers is not the direct cause of earthquakes, it likely modulates both the timing and severity of seismic events. They grind past each other at about two inches per year - roughly twice the rate of the San Andreas fault in California - resulting in frequent earthquakes. USGS status: Reviewed by a seismologist Reports from the public: 0 people 15:02:25 UTC 1.5 magnitude, 0 km depth Bear Creek, Alaska, United States. Southern Alaska sits at the boundary between the continental North American plate and the Pacific Plate. USGS page: M 1.5 Ice Quake - 26 km WNW of Chenega, Alaska. Unexpectedly, the greatest amount of stress from ice loss occurred near the exact epicenter of the 1958 quake that caused the Lituya Bay tsunami. The disappearance of glaciers has caused Southeast Alaska’s land to rise at about 1.5 inches per year. Rollins ran models of earth movement and ice loss since 1770, finding a subtle but unmistakable correlation between earthquakes and earth rebound. ![]()
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