Page 2/3 - Posted May 28, 2010
“The best outcome of the whole season was the ice core at Site Beta,” Domack said, referring to the camp on the Bruce Plateau. The Palmer parked in an area called Barilari Bay, just 12 nautical miles from the camp, where it drilled several sediment cores, which scientists can study for a number of purposes, from looking at the biology of the tiny critters living in the seafloor to reconstructing past climate conditions.
“We felt that getting some long cores of marine sediment from there off the ship would complement the climate record from the ice core in a way that we hadn’t planned on,” Domack said.
One of the main goals of the project is to build a climate history of the region to determine if the breakup of the Larsen B Ice Shelf in 2002 was part of a long-term natural cycle or an aberration brought on by climate change.
Previously, Domack and colleagues determined that the Larsen B had been in place for at least 10,000 years, during most of the present-day Holocene. The current epoch represents a naturally warmer interglacial period between ice ages, exacerbated in recent decades by human influences on the environment. The Last Glacial Maximum occurred about 20,000 years ago, when ice sheets even draped across parts of the present-day United States.
Sediment cores from the seafloor around the continental margin of Antarctica are nothing new. However, gleaning a climate record from analysis of the cores can be tricky and ambiguous. Domack said the cores from Barilari Bay would complement the Site Beta ice core and provide key insights into the best ways to interpret sediment cores for paleoclimate work.
“It’s going to be the Rosetta stone of going from ice cores to marine sediments,” he said.
On the go
Another team of glaciologists, headed by Ted Scambos , lead scientist at the University of Colorado’s National Snow and Ice Data Center (NSIDC) , benefited from the quick work by Mosley-Thompson’s group.
A ski-equipped Twin Otter used to support the ice-core team was now available to fly Scambos’ crew from Rothera to the eastern side of the peninsula to install several AMIGO stations, for Automated Meteorology Ice Geophysics Observation systems.
These heavy-duty polar probes have built-in GPS units and weather station instrumentation. The AMIGOs, which also sport high-resolution cameras, should give the scientists additional insight into how the glaciers in the area behave, as well as how the remaining sliver of the Larsen B Ice Shelf evolves.
The team was able to set up three AMIGO systems and two separate GPS stations, despite spates of bad weather that grounded aircraft and stranded the scientists in temporary field camps for days at a time. Eventually, the glaciologists reunited with their colleagues on the ship via a rather circuitous route that took them from Scar Inlet on the east side of the peninsula back to Rothera.
From the British base, the scientists flew to Palmer Station , a U.S. Antarctic Program base on Anvers Island. The trick was that Palmer Station has no airfield, only a pier, so the Twin Otter had to land on a soft glacier behind the base.
On the team’s blog , Scambos noted that the runway was less than ideal: “It was the most rutted, cracked-up, slush-pit of a glacier I’d ever seen. It was sloped, with the end of it as steep as a ski run, leading straight to a boulder field.”
But the plane landed safely at Palmer Station, where the ARSV Laurence M. Gould , another USAP research vessel, was standing by to transfer the glaciologists to the Palmer for the northbound trip to Punta Arenas, Chile.
A veteran of nearly a dozen polar expeditions, Scambos said later via e-mail that the LARISSA project wasn’t his roughest physical challenge in Antarctica, but logistically it was the toughest.
“We needed to use all our resources, needed to be prepared to do any part of the work at any time, and we needed to be able to react to a completely different approach with short notice,” he said after returning home to Boulder, Colo. “But, I have to say, NSF was flexible and imaginative right along with us, and we were able to get a lot done. Otherwise, the ice conditions and the weather limitations — lots of low clouds — would have almost completely shut us down.”Back 1 2 3 Next