Ice mass loss (Gt) in Greenland, 2003-2013, estimated from NASA's GRACE satellite measurements. Graphic: Velicogna, et al., 2014

3 December 2014 (AFP) – The melt rate of glaciers in the fastest-melting part of Antarctica has tripled over the past decade, researchers said Tuesday in an analysis of the past 21 years. Glaciers in the Amundsen Sea in West Antarctica are losing ice faster than another part of Antarctica and are the biggest contributor to rising sea levels, said researchers at the University of California at Irvine and NASA’s Jet Propulsion Laboratory. Research published in May concluded that the melting of glaciers in West Antarctica, which contain enough water to raise sea levels by at least a meter, is speeding up and seems irreversible. The study is the first to assess and reconcile observations from four different measurement techniques so as to generate an authoritative estimate of the amount and the rate of loss over the last two decades, said the researchers. Their work will be published in the journal Geophysical Research Letters dated 5 December 2014. “The mass loss of these glaciers is increasing at an amazing rate,” said scientist Isabella Velicogna, jointly of UCI and NASA’s Jet Propulsion Laboratory. “Previous studies had suggested that this region is starting to change very dramatically since the 1990s, and we wanted to see how all the different techniques compared,” said lead author Tyler Utterley of UCI. “The remarkable agreement among the techniques gave us confidence that we are getting this right,” he said. [more]

Antarctic Ice Loss Tripled in the Last 10 Years

ABSTRACT: We use Gravity Recovery and Climate Experiment (GRACE) monthly gravity fields to determine the regional acceleration in ice mass loss in Greenland and Antarctica for 2003–2013. We find that the total mass loss is controlled by only a few regions. In Greenland, the southeast and northwest generate 70% of the loss (280±58 Gt/yr) mostly from ice dynamics, the southwest accounts for 54% of the total acceleration in loss (25.4±1.2 Gt/yr2) from a decrease in surface mass balance (SMB), followed by the northwest (34%), and we find no significant acceleration in the northeast. In Antarctica, the Amundsen Sea (AS) sector and the Antarctic Peninsula account for 64% and 17%, respectively, of the total loss (180±10 Gt/yr) mainly from ice dynamics. The AS sector contributes most of the acceleration in loss (11±4 Gt/yr2), and Queen Maud Land, East Antarctica, is the only sector with a significant mass gain due to a local increase in SMB (63±5 Gt/yr).

Regional acceleration in ice mass loss from Greenland and Antarctica using GRACE time-variable gravity data