A new study led by PhD student Melissa Hansen published in Paleoceanography sheds light on the behavior of the East Antarctic Ice Sheet in a warming world. The Antarctic Ice Sheet is the largest in the world and it has some vulnerable areas where the ice lies below sea level. Today, under the current warming climate, the Antarctic ice sheet is gaining mass at the top due to an increase in snow accumulation, but it is melting from below where it is in contact with warmer ocean water. In East Antarctica, snow accumulation exceeds the melt from below, but recent studies have given evidence of a different balance in a warmer climate. Ms. Hansen and her co-authors show that when ocean temperatures around Antarctica rose to more than 3 degrees Centigrade during past warm periods, the East Antarctic ice mass changed from one purging icebergs into the ocean following glacial rhythms to one with a very different dynamic. These results confirm earlier studies that the East Antarctic Ice Sheet might not be as stable under warmer conditions with consequences for predictions of future sea level rise.
PhD student Melissa Hansen collected data on a sediment core from the Antarctic margin retrieved by shipboard drilling of the Integrated Ocean Drilling Program in 2010. Ms. Hansen: “Being able to work on a project like this is such an exciting experience. For me, working in the lab with material which is millions of years old is so surreal. No one was around back then to tell us how the ice sheets were responding to climate changes, and we can now use these types of environmental archives to divulge their history.” Ms. Hansen carried out her research in the Sedimentology lab at Montclair State University. The Sedimentology lab recently moved to the new Center for Environmental and Life Sciences.
Ms. Hansen: “Being able to work with all the various instruments to collect data is my favorite part, and that’s where the story really begins to develop. It’s a lot of work sometimes to prep all the samples, but when you see the data and all the different trends and patterns, it gets really interesting and you start to see the story. In the end, the research we do is important because it highlights our understanding of what was going on in past warm climates and the implications that may hold for the future.”
Hansen, M. A., S. Passchier, B.-K. Khim, B. Song, and T. Williams (2015), Threshold behavior of a marine-based sector of the East Antarctic Ice Sheet in response to early Pliocene ocean warming, Paleoceanography, 30, 789’801. doi:10.1002/2014PA002704.