Tag Archives: glacial

Earthquakes caused by glaciers melting?

An acquaintance in Facebook recently posed the question:

Does global warming cause earthquakes?

After the Eastern Seaboard experienced a 5.8 magnitude earthquake, it left many wondering, what the hell was that?

Before the recent disruption the largest earthquake on record in central Virginia was a magnitude 4.8 temblor that occurred in 1875.

Earthquakes are rare in the eastern U.S. because the region is farther from a fault line.

Andrew Hynes, a tectonics expert at McGill University, said the issue is not so much the load shift on the earth’s crust, but rather the increased fluid pressure in the fault that lubricates the rock, allowing the plate to slide.

 “All earthquakes except those produced by volcanic activity are essentially the unsticking of faults,” he said. In other words, if you pump fluid into a fault, it will reduce the friction and the rock can slide. (from AccuWeather)

Can the added melt from glaciers create stress on the earth’s upper crust, injecting more fluid into the rocks, thus creating earthquakes? The answer is yes, earthquakes at shalllow depths. Which is exactly what states like VA, MD, NY, and NC experienced.

Metereolists and geologists have long been warning of the consequences of “post glacial rebound” when the melting of glaciers causes an increase in global sea levels.

This increase in sea level means more pressure on the sea floor, which can effect everything from gravity fields to horizontal crustal motion. Of course, the recent earthquake on the East coast brings to mind the threat of shifting tectonic plates.

As the world’s glaciers perform an accelerated disappearing act, earthquakes just may be the first sign of how the warming will change the world.