资源环境科技发展态势分析平台

As it turns out, one of the most challenging parts of camping on an ice shelf for a few weeks is brushing your teeth (and keeping toothpaste thawed). Last Antarctic spring (October-November 2016), we became familiar with what it takes to stay warm and comfortable while living atop the Ross Ice Shelf (RIS), a Spain-sized ice platform floating in the Ross Sea.

We are Alan Seltzer and Momme Hell, graduate students at Scripps Institution of Oceanography at the University of California San Diego, and this article along with its associated photo album tell the tales of our recent field work. Together with researcher Melissa Carter, we formed a Scripps team that worked as part of collaborative effort to retrieve instruments buried in the ice since 2014. These instruments have been recording seismic data since their original installation, and this field season marked the end of a two-year study. The multi-institutional research project to measure vibrations throughout the RIS induced by ocean waves was led by Scripps researchers Peter Bromirski and Peter Gerstoft along with scientists at Woods Hole Oceanographic Institution, Pennsylvania State University, Colorado State University, and Washington University in St. Louis.

In total, we spent 18 days camping on the ice (and many more at McMurdo Station), making day trips via Twin Otter planes or snowmobiles to seismometer stations spread throughout the RIS. Our training location and the waypoint between New Zealand and our campsite was McMurdo Station (~78°S), the largest American base on Antarctica. After completing our training for crevasse safety, camping, and snowmobile driving at McMurdo, we headed to the middle of the RIS for our stint on the ice at a temporary site informally known as “Yesterday Camp” because it (nearly) straddles the date line.

Each member of our group was given a personal tent, laid out in a grid. Along with our science party of nine were three camp staff, two pilots, a mechanic, and a composer named Glenn McClure who documented our trip both with photographs and musically with a symphony he is currently composing based on seismic data recorded in the RIS. Glenn’s artistic account of the trip will soon be on display at Birch Aquarium at Scripps.

On a day-to-day basis, we would either head out to seismic stations to dig deep trenches and recover instruments, or, quite often, we would hang around at the campsite if the weather would not cooperate with our plans. In the cold, human bodies burn calories much more quickly to stay warm, so digging for hours meant eating lots of candy and energy bars throughout the day. Fortunately, we had boxes and boxes of frozen bars to keep us energized. At night, we were free to relax, play spikeball and board games, or toss the Frisbee (remember it’s light 24 hours-a-day down there in November!).

Back at Scripps and other collaborating institutions, researchers are now busy analyzing two full years of high-resolution data. The results may shed light into the structural integrity of the RIS and may provide key insight into the response of an ice shelf to ocean waves. From high-frequency ocean swell to large single events (like the 2015 Chilean tsunami), these seismic records tell the story of the past two years narrated from the ice shelf’s perspective. Scientists are particularly interested in ice shelf stability because these shelves act as buttresses for land ice, which, if lost, would contribute to global sea-level rise.

As we wrapped up our campsite-based work, persistent fog kept us from being able to fly back to McMurdo for eight additional days. Keeping occupied was a good challenge, and a rerouted flight on its way to pick us up was a test of patience, but reading, games, and building a snow pit kept us entertained. We hope you enjoy our photos.

-Alan Seltzer is a third-year student in the lab of geoscientist Jeff Severinghaus and Momme Hell is a second-year student in the oceanography/geophysics groups of Art Miller, Peter Bromirski and Sarah Gille.