Melting ice can cause earthquakes

When the ice sheets melt, they can release the compacted energy and cause terrible earthquakes. The warming of Earth may be the cause of such earthquakes and will continue in the future as the ice continues to melt globally.

Scientists have pointed to a series of massive earthquakes that shook northern Europe, Scandinavia about 10,000 years ago, along with inactive cracks today. The time of each earthquake coincides with the melting process of thick ice sheets from the last ice age in these places. Scientists suspect the melting caused these earthquakes by releasing the pressures created on the earth's crust.

Now, a new study is the first to use complex computer models to simulate the effect of ice on the earth's crust in this area. According to lead researcher Andrea Hampel of the Ruhr University Bochum in Germany, this work shows that earthquakes are "suppressed when there is ice and motivated when the ice melts."

Hampel and a colleague had previously found evidence that the loss of a large lake at the end of the last ice age caused a series of Utah earthquakes. The new work shows that this can happen with cracks that are still quiet and unable to slip.

The work will be published in Earth and Planetary Science Letters .

Ancient earthquakes shook Scandinavia.

Earthquakes moved northward through Scandinavia as the ice sheets retreated. They started in the south, Sweden today, 12,000 years ago, then attacked in central-southern Sweden near present-day Stockholm about 10,500 years ago.

Finally the earthquakes entered Lapland, northern Scandinavia about 9,000 years ago. Based on the cracks that slipped out, it was speculated that these earthquakes were quite large, at 8 on the Richter scale - larger than the earthquake that destroyed Kashmir in 2005.

Columbia's glacier of Alaska is gradually receding in recent years.When the ice sheets melt, they can emit compelling energy and cause terrible earthquakes.A previously isolated building found small earthquakes increasingly popular in Alaska in the summer when the ice melted.(Photo: National Geographic)

Today, cracks in Scandinavia rarely cause earthquakes. If so, these shakes are usually less than 5 degrees. Hampel said: 'With the new technology we can simulate cracks and directly compare the slip on the model with a real slide in nature.'

This model shows that thick ice can suppress the mainland, preventing a crack from sliding and causing energy storage. The thicker the simulated ice - from 100 to 2,000 meters - the more it restrained earthquakes and the more violent the earthquake was after the ice sheets melted.

"The amount of movement on the crack in the model is consistent with the actual level of slip that is supported by the assumption that thawing caused earthquakes ," Hampel said.

Global warming causes earthquakes?

Such earthquakes are not just a thing of the past but can happen today as global warming is melting ice around the world.

Hampel and his colleagues wrote in their work: 'The frequency of earthquakes will increase in the future if the ice continues to melt. The current earthquakes in Greenland and Antarctica have low levels, possibly due to the presence of giant ice sheets. '

Jeanne Sauber of NASA's Goddard Aviation Center, Greenbelt, Maryland, led the work to prove that earthquakes increased in Alaska when the ice melted the most. Completely unexpected, between 2002 and 2006, warmer temperatures and more melting ice.

Even if the ice thickness is only 10% or less, this is obviously enough to cause small earthquakes in the summer when the ice melts. Large earthquakes are difficult to observe because they do not occur often.

'We hope that if the ice starts to melt quickly in Greenland and Antarctica, we can observe at least a few small earthquakes.'