Earthquakes have become more frequent in the United States’ Alaska region. Scientists have attributed that they may have got nothing to do with natural movement of tectonic plates but everything to do with climate change.
A paper titled “Stress Promotion of the 1958 Mw∼7.8 Fairweather Fault Earthquake and Others in Southeast Alaska by Glacial Isostatic Adjustment and Inter‐earthquake Stress Transfer” in the Advancing Earth and Space Science journal has shown how melting of glaciers in Alaska’s is causing the earth to rebound.
Researchers at the University of Alaska Fairbanks Geophysical Institute mention that Alaska has some of the world’s largest glaciers, that can be thousands of feet thick and cover hundreds of square miles. This massive accumulation of large masses of frozen ice creates an equally massive weight that causes the land beneath it to sink. And now when the temperature of the planet is on the rise at an unnatural rate due to greenhouse gases, these glaciers are melting.
When large chunks of glaciers melt into the warming seas the ground beneath the erstwhile frozen ground springs back like a sponge which in turn creates earthquakes in the region.
Chris Rollins, the study’s lead author who conducted the research said there are two components to the uplifting movement. He said the first is called the ‘elastic effect,’ which is when the earth instantly springs back up after an ice mass is removed and the second is the prolonged effect from the mantle rising back upwards under the vacated space.
Researchers link the expanding movement of the mantle with the frequent earthquakes across Southeast Alaska, where glaciers have been vanishing for over 200 years. In this region more than 1,200 cubic miles of ice have been lost in the two centuries.
The Southern Alaska region shares the boundary in the middle of the continental North American plate and the Pacific Plate that rubs past each other at about two inches per year. The vanishing glaciers have also caused Southeast Alaska’s land to rise at about 1.5 inches per year.