Dr Kevin Norton from the School of Geography, Environment and Earth Sciences (SGEES) and Dr Andrew Mackintosh from SGEES and Victoria’s Antarctic Research Centre are among six experts from around the country to receive funding from the New Zealand Antarctic Research Institute.
Each research project will, over the next two years, explore various aspects of Antarctic ice, with a focus on how and why the ice may change in the future.
Dr Mackintosh’s project will look back to a period known as the ‘Antarctic Cold Reversal’—around 14,000 years ago.
“During this period of global warming, some geological records and computer simulations suggest that a large Antarctic meltwater release actually caused Southern Hemisphere-wide climate cooling that affected New Zealand,” says Dr Mackintosh.
Dr Mackintosh will work with Dr Brian Anderson from Victoria’s Antarctic Research Centre, Dr Norton, recent Victoria PhD student Shaun Eaves, Dr Andrew Lorrey and Dr Helen Bostock from NIWA and researchers from the University of Copenhagen and Columbia University in New York.
The team will examine the surface of glacial boulders from the Spenser Mountains in the South Island, and create a computer model of past climate changes to help understand the cause of the Antarctic Cold Reversal and its downstream impacts on New Zealand.
“We want to find out if future Antarctic melting could have similar, unexpected consequences for New Zealand’s climate,” says Dr Mackintosh.
Dr Norton’s project will also look back 14,000 years to the ‘Antarctic Cold Reversal’, focussing on the possible source of rapid sea level rise at the time in Antarctica.
Working with Dr Nick Golledge, Dr Cliff Atkins, Dr Mackintosh, PhD student Richard Jones and collaborators from the University of California Berkeley and Durham University, Dr Norton hopes to pinpoint the origin of the ice sheet melting, which may have caused a 20 metre rise in sea level in less than 500 years.
“We’re looking at an area in Northern Victoria Land, which was close to the limits of the ice sheet prior to its collapse at the end of the last ice age,” says Mr Jones. “We’ll use glacier modelling to test how sensitive the ice sheet was to possible collapse in this region.”
Dr Norton’s team will travel to Antarctica next year to collect rock samples, which will be analysed in Victoria’s purpose-built laboratory.
Both projects will date rocks using a technique called 'cosmogenic nuclide dating', which identifies small changes in rock composition that occur over time and provides an estimate of the time since the boulders emerged from the glaciers.
Dr Norton says understanding past changes in ice sheets are important for predicting their future response.
“One of the big things to understand is around currently retreating ice sheets—is that just the beginning? Are we looking at 400 years of rapid retreat? Or are these natural fluctuations? It has very large repercussions for what the world may look like over the next few centuries.”
During his PhD studies, Richard Jones created a video of the sort of field work and data collection the researchers will be doing in Antarctica.
Watch the video on Vimeo.