for National Geographic News
As ice sheets melt, they can release pent-up energy and trigger massive earthquakes, according to new study.
Global warming may already be triggering such earthquakes and may cause more in the future as ice continues to melt worldwide, the researchers say.
A series of large earthquakes shook Scandinavia around 10,000 years ago, along faults that are now quiet, the scientists point out.
The timing of each earthquake roughly coincided with the melting of thick ice sheets from the last ice age in those same places.
Researchers had suspected that the melting had triggered these earthquakes by releasing pressure that had built up in Earth's crust.
Now a new study, the first to use sophisticated computer models to simulate how ice sheets would affect the crust in the region, bolsters this scenario.
The study showed that earthquakes are "suppressed in presence of the ice and promoted during melting of the ice," said study leader Andrea Hampel of the Ruhr University Bochum in Germany.
Hampel and a colleague had earlier found evidence that the shrinkage of a huge lake at the end of the last ice age had triggered a series of large earthquakes in Utah.
The new study shows this can happen even along faults that are normally quiet and are not prone to slip.
The new research will be published soon in the journal Earth and Planetary Science Letters.
Ancient Quakes Rocked Scandinavia
The ancient earthquakes marched northward through Scandinavia as ice sheets retreated.
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