New Zealanders out to uncover icy secrets
15 November 2017
New Zealanders out to uncover icy
A University of Otago-led research team is about to embark on an epic Antarctic research expedition as part of efforts to better understand how the Ross Ice Shelf (RIS) will respond to global warming.
The multi-disciplinary and international team includes researchers from Otago, Victoria University of Wellington, Canterbury University, Waikato University, NIWA, GNS Science, Georgia Tech in the US, and the Chinese Polar Research Institute.
In mid-November, the team will join with engineers who have already journeyed to the field site, 350 kilometers away from Scott Base. The engineering team are assembling a New Zealand-built drill that will use hot water to bore through hundreds of metres of glacial ice to access the ocean and sea floor beneath their remote camp.
The RIS is Earth’s largest expanse of floating glacial ice. It is fed by glaciers flowing from the West Antarctic Ice Sheet and through the Transantarctic Mountains and by new snow falling on its surface. The ice is continually moving, flowing away from the land and toward the open ocean, eventually breaking off as icebergs. The ice is moving nearly 2 metres per day at the drilling site.
Project scientists first visited the site two years ago, when they used seismic techniques to image the sea floor and installed a weather station to monitor conditions. A team of 3 returned last year to recover data from the weather station.
This year’s team is much larger, a 5-person drilling crew, 24 scientists, and 3 Antarctica New Zealand camp staff. The programme of work will last a lot longer, about 65 days all together. Not everybody will be at the camp at the same time. Two overland traverses are moving the heaviest equipment to the site while most of the scientists and smaller gear will fly via Twin Otter. The phased approach will help the team to manage resources and the camp’s impact.
The research is just as complicated as the large team implies. Once the drilling crew has created the borehole, oceanographers and geophysicists will install instruments for long-term monitoring of conditions in the ocean cavity and the ice shelf. Geologists will lower a core barrel down the hole to sample sediments on the sea floor. A remotely-operated submarine on a 3 kilometer long tether will dive down the borehole to observe ocean, sea floor, and ice conditions in the area all around the drill site. Back at the surface, an atmospheric physicist will install a regional network of smart weather stations and geophysicists and surveyors will use ice penetrating radars and acoustic techniques to image internal structures of the ice shelf.
The field team is led and coordinated by Professor Christina Hulbe and Dr Christian Ohneiser at the University of Otago. Professor Hulbe says the overall goal of the research programme is to understand the processes and ice/ocean interactions that matter most for change in the region. “We know that in the past, climate warming caused ice shelf and ice sheet retreat in the Ross Sea. Now we need to find out more about the actual physical processes and the rates at which they act. That knowledge is one of the keys to making better projections of future change”. She also emphasizes that every member of the team is a leader. “Our team seems large, but really, it’s as small as it can be. We are working at the limits of what is possible, as efficiently and effectively as we can. It’s an exciting place to work; the environment, the science, and the people are all excellent.”
Dr Ohneiser adds “The RIS is a major interface between the West Antarctic Ice Sheet (WAIS) and the Southern Ocean. At the moment the RIS appears to be stable but we don’t know for sure but we do know that it has changed quickly in the past. We need data from the places that are still covered by ice… not just at the easy to get to places around the edge.”
The Otago scientific team includes Professor Hulbe, Dr Ohneiser, Kelly Gragg, Dr Sergio Morales, Dr Federico Baltar, Lisa Craw, Holly Still, Martin Forbes.
Victoria University of Wellington Scientists Dr Gavin Dunbar and Georgia Grant, Dan Lowry and drilling crew Alex Pyne (chief driller), Jane Chewings, Hedley Berge, Jeff Rawson, Darcy Mandeno.
Canterbury University scientist Dr Adrian McDonald, NIWA scientists Dr Craig Stevens and Mike Brewer, Waikato University scientist Shelly Brandt, Auckland University Scientists Dr Jennifer Eccles and Franz Josef Lutz.
And international collaborators Dr Britney Schmidt and her team (NASA, Georgia Tech, USA) and Prof Wei Luo (China)
The team will be joined by a journalist from New Zealand Geographic.
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