Concerning new research suggests the thickness of Antarctica's floating ice shelves has decreased by as much as 18 percent in certain areas over the past 20 years.
The findings provide insight into how the ice sheet is responding to climate change, the University of California, San Diego reported.
A team of researchers used satellite data to construct a new high-resolution record of ice shelf thickness from 1994 to 2012. The total ice shelf volume (thickness multiplied by area) across Antarctica did not show much changed between the years of 1992 and 2003, but it rapidly declined in the years following. West Antarctic ice shelves appeared to lose ice throughout the entire observation period, but the loss accelerated over the past decade. Despite gains in the East Antarctic ice sheet, the region also started to rapidly lose ice after 2003.
"Eighteen percent over the course of 18 years is really a substantial change," said Scripps graduate student Fernando Paolo. "Overall, we show not only the total ice shelf volume is decreasing, but we see an acceleration in the last decade."
The melting ice sheets do not contribute directly to sea level rise, but it is believed to have an indirect effect. Since the ice shelves hold grounded ice flow from reaching the ocean, their loss could allow this flow to contribute to sea level rise.
"This work demonstrates the power of satellite observations to understand change in the great polar ice sheets," said Thomas Wagner, Program Manager for Cryospheric Sciences at NASA Headquarters. "And with data spanning decades, we can understand some of the most important changes and their implications for sea-level rise."
In the future, the researchers plan to investigate the causes behind the rapid loss of ice shelf volume as well as how the changes will influence the atmosphere and ocean.
"We're looking into connections between El Niño events in the tropical Pacific and changes in the Antarctic ice sheet," Paolo said. "It's very far apart but we know that these teleconnections exist. That may ultimately allow us to improve our models for predicting future ice loss."
The findings were published in a recent edition of the journal Science.
