Canterbury researcher looking at Antarctic glacier behaviour

Canterbury researcher looking at Antarctic glacier behaviour in critical areas

November 9, 2014

A University of Canterbury researcher is heading a project which has received a $345,000 Marsden grant to look at short-term glacier behaviour in critical areas of Antarctica.

Dr Oliver Marsh, from the University of Canterbury’s Gateway Antarctica team, will over the next three years be studying movement of the ice at the ice sheet-ice shelf boundary using satellite data and linking it to future sea level rise. He will observe the effects that ocean tides beneath the ice shelves have on the flow of outlet glaciers.

``With 65 percent of New Zealanders living within five kilometres of the coast, sea level rise will become increasingly important over the next few decades, affecting town planning, economic policy and disaster management,’’ Dr Marsh says.

``The Antarctic ice sheet is a major contributor to sea level rise and is vulnerable to ongoing oceanic and atmospheric warming, but while it is known that Antarctic mass loss has increased over the last 20 years, there are still a wide range of sea level rise projections for the next century.

``Areas of Antarctica where warm ocean waters intrude into the cavities beneath ice shelves are particularly sensitive and this is where the greatest changes are currently occurring. By studying these regions in greater detail than previously possible we can narrow down the uncertainties in ice sheet mass-balance.

``Ocean tides affect how the ice behaves and provide us with a natural laboratory to investigate ice rigidity and flow properties. Glacier velocities can vary by up to 50 percent over a single day due to the influence of the tides. It is not well understood how this behaviour varies from glacier to glacier or the overall effect of tidal-induced variation on average velocity or long-term trends.

``We will observe movement of the ice in the grounding zone with centimetre precision using a satellite technique called interferometry. To validate our satellite measurements we will also collect ground-based measurements of ice thickness and surface movement using GPS receivers located on the ice.

``The satellite technique can be applied to remote and poorly understood areas of Antarctica and by modelling how the ice bends in response to tides and how this bending effects short-term ice velocities we will better understand ice characteristics and processes occurring at the ice sheet margins ,’’ Dr Marsh says.

Researchers from the University of Canterbury was awarded a total of $4.43 million in funding over three years in the latest Marsden round, including Professors Mark Billinghurst, Deak Helton, Matthew Turnbull, Paul Kruger and Emily Parker, Associate Professor Jenni Adams, Dr Catherine Theys and Dr Marsh.

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