North East experts find climate change makes the Earth move

North East university scientists have plotted the impact of climate change beneath the Earth's crust

A GPS monitoring site in the Antarctic Peninsula
A GPS monitoring site in the Antarctic Peninsula

Climate change is making the Earth move, North East academics found.

Studies led by Newcastle University, and involving Durham University, have revealed upward movements of rock beneath the surface in Antarctica at a much faster rate than expected.

Previous studies have shown land is “rebounding” due to overlying ice sheets shrinking in response to climate change.

This was understood to be due to an elastic response followed by a very slow uplift over thousands of years since the end of the last Ice Age.

The “hinge” for this effect in the UK is around the Tyne and the Tees, with land to the north slowly rising after the removal of the weight of Ice Age sheets, while land to the south is sinking.

But GPS data collected by the universities has revealed the land in Antarctica is actually rising at a rate of 15mm a year – at least three times as fast than can be accounted for by the “elastic” response alone.

And the experts have shown for the first time how the mantle - or hotter rock beneath the crust - in the Antarctic Peninsula is flowing faster than expected. This means it can flow more easily and so responds much more quickly to the lightening load hundreds of miles above it, changing the shape of the land.

Lead researcher, PhD student Grace Nield, based in the School of Civil Engineering and Geosciences at Newcastle, said: “You would expect this rebound to happen over thousands of years and instead we have been able to measure it in just over a decade. You can almost see it happening, which is just incredible.

“Because the mantle is ‘runnier’ below the Northern Antarctic Peninsula it responds much more quickly to what’s happening on the surface. So as the glaciers thin and the load in that localised area reduces, the mantle pushes up the crust.”

Since 1995 several ice shelves in the Northern Antarctic Peninsula have collapsed because of climate change.

“Think of it a bit like a stretched piece of elastic,” said Ms Nield, whose project is funded by the Natural Environment Research Council. “The ice is pressing down on the Earth and as this weight reduces the crust bounces back. But what we found when we compared the ice loss to the uplift was that they didn’t tally – something else had to be happening to be pushing the solid Earth up at such a phenomenal rate.”

Peter Clarke, professor of geophysical geodesy at Newcastle University and one of the authors of the study, said: “Seeing this sort of deformation of the Earth at such a rate is unprecedented in Antarctica. What is particularly interesting here is that we can actually see the impact that glacier thinning is having on the rocks 250 miles down. A rapid rate of rebound is happening on top of the rebound from thousands of years ago. This more rapid uplift is a manifestation of climate change over the last few decades.”

Journalists

David Whetstone
Culture Editor
Graeme Whitfield
Business Editor
Mark Douglas
Newcastle United Editor
Stuart Rayner
Sports Writer