Using NASA and the German Aerospace Center’s Gravity Recover and Climate Experiment satellites (GRACE), researchers at the University of Colorado at Boulder have discovered that the Earth’s ice caps and glaciers lost a mammoth amount of water between 2003 and 2010. The group used NASA’s data to research global ice loss from Greenland, Antarctica, glaciers, and ice caps and deduced that the total loss was 4.3 trillion tons (or 1,000 cubic miles) of ice — that’s about eight times the water volume of Lake Erie and enough to make a 1.5 foot-deep lake the size of the United States. This comprehensive study was the first of its kind and it was carried out to help understand the implications of Earth’s rising sea levels and how quickly they could affect our lives.
“This is the first time anyone has looked at all of the mass loss from all of Earth’s glaciers and ice caps with GRACE,” said CU-Boulder physics Professor John Wahr. “The Earth is losing an incredible amount of ice to the oceans annually, and these new results will help us answer important questions in terms of both sea rise and how the planet’s cold regions are responding to global change.” Excluding Greenland and Antarctica the group found that our glaciers and ice caps are shedding about 150 billion tons of ice annually.
GRACE — the satellites which collected the data used in the study — is a pair of gravity sensing data gatherers that circle the world 16 times a day about 135 miles apart at a height of about 300 miles. The two measure changes in Earth’s gravity field due to regional changes in mass, which includes measurements of ice sheets, oceans and water — even water buried underground in aquifers. By following the measurements from the satellites over the eight year period the group was able to deduce the ice lost over time.
“One big question is how sea level rise is going to change in this century,” said Professor Tad Pfeffer of CU-Boulder’s Institute of Arctic and Alpine Research. “If we could understand the physics more completely and perfect numerical models to simulate all of the processes controlling sea level — especially glacier and ice sheet changes — we would have a much better means to make predictions. But we are not quite there yet.” The study does not look into the direct causes of the ice melt, it just deeply investigates the extent at which it is melting.
Lead image by d’n'c on Flickr
Second image by Kimberly KV on Flickr