Anna Shane sends me this dramatic news that global warming has melted enough antarctic ice to change the shape of the earth to the extent scientists can measure it. RDMag reports the strange news that Ice-loss moves the Earth 250 miles beneath our feet. Yes, we seem to have lost enough ice that the reduced weight on the surface of the Antarctic continent is allowing the flows of magma 250 miles beneath the surface to cause a 15 mm bulging of the earth's surface detectable by geologists!
Calling all climate change deniers! "Call for global warming deniers, line 1." Let's spell this out in a way that even climate deniers might understand: due to global warming enough ice has melted on the Northern Antarctic ice shelve to change the shape of the earth enough that geologists can measure it with existing scientific measuring devices!
GPS data ... has revealed that the land in this region is actually rising at a phenomenal rate of 15 mm a year—much greater than can be accounted for by the present-day elastic response alone. “Think of it a bit like a stretched piece of elastic,” says Nield, ... “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.”
Collating data from seven GPS stations situated across the Northern Peninsula, the team found the rebound was so fast that the upper mantle viscosity - or resistance to flow - had to be at least ten times lower than previously thought for the region and much lower than the rest of Antarctica.
Professor Peter Clarke, Professor of Geophysical Geodesy at Newcastle University and one of the authors of the paper, adds: “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.”
This "rebounding" is most noticeable in the Northern Antarctic Peninsula as the ice sheets melts. This research was published in the letters section of the Earth and Planetary Science Letters. GPS data shows the land in this region is rising a "phenomenal rate of 15 mm a year."
These scientist have also shown that the magma flowing 250 miles beneath the Antarctic regions is flowing much faster than previously thought which explains why the observed "rebounding" effect is over 10 times faster than was expected given the amount of ice lost. The amount of bulging observed in the last 10 years was expected to occur over the next 1,000 years.
Several ice shelves in the Northern Antartic Peninsula have collapsed since 1995 triggering "ice-mass unloading causing the solid Earth to "bounce back."
Let me say it again in a way climate deniers might understand. Due to global warming enough ice has melted on the Northern Antarctic ice shelve to change the shape of the earth enough that geologists can measure it with existing scientific measuring devices.
Or as these scientist like to explain it "rapid bedrock uplift in the Antarctic Peninsula explained by viscoelastic response to recent ice unloading." Maybe I should change my title to "Scientists measure change in shape of earth due to global warming!" And, thanks again to Anna Shane for sending us this article.
5:38 PM PT: Changed "earth" to "continent" as per suggestion of Crashing Vor to be more precise, in this sentence. "Yes, we seem to have lost enough ice that the reduced weight on the surface of the Antarctic continent is allowing the flows of magma 250 miles beneath the surface to cause a 15 mm bulging of the earth's surface detectable by geologists!"