Researchers at the UC San Diego Scripps Institution of Oceanography released a new study on Thursday revealing that Antarctica’s floating ice shelves have decreased in thickness by up to 18 percent in the last two decades.
The study was published in the journal Science and the findings have been backed by NASA. The study uses two decades of satellite imaging data, from 1994 to 2012, to show that the total volume of Antarctica’s ice shelves has not only dropped by up to 18 percent in certain areas, but the loss of total volume has been accelerating.
From 1994 to 2003 ice shelf volume remained relatively static, then began melting rapidly. In West Antarctica the ice shelves continually lost volume throughout the study period, accelerating after 2003. In East Antarctica initial gains were halted in 2003 and showed little signs of progression.
UC San Diego graduate student Fernando Paolo, who participated in the research alongside Scripps glaciologist Helen Fricker and Earth & Space Research institute oceanographer Laurie Padman, noted how remarkable the findings were. “Eighteen percent over the course of 18 years is really a substantial change,” Paolo said.
The study noted that at the current melting rate, West Antarctica could lose half of its ice shelf volume in the next 200 years.
What is the cause? The overall suggestion from the study is climate change, however the team is also considering the effects of a particularly strong El Niño in the Pacific Ocean sweeping down and causing longterm melting.
The question from all this for the layman becomes: what does it matter? The study explains that while melting ice shelves do not actually contribute to sea-level rise in themselves, an indirect effect occurs. Fricker explained that floating ice shelves control the flow of ground ice on the seafloor into the ocean, and with less of an ice shelf blocking some of the flow, the more ice topples into the sea, which does raise the Earth’s sea-level.
The study uses altimetry data from satellites, a newer research tool. Beforehand glaciologists would use pictures and other tools from the ground, which could capture general trends but had difficulty seeing larger effects over time. The research team plans to continue using satellite date to enhance their observations.
