Climate change in Antarctica: A scientist's crucial investigationby Sharon Stephenson
Scientist Rob McKay is on a mission to Antarctica to investigate the impact of climate change.
McKay, a senior lecturer in geology at Victoria University’s Antarctic Research Centre, is leading a team of 30 scientists from around the globe on a two-month expedition to discover how the West Antarctic Ice Sheet and the adjacent Southern Ocean are responding to changes in temperature.
“We are drilling firstly offshore from the Ross Ice Shelf, and then into the Southern Ocean, to collect sediment that will help us understand the stability of the ice sheet through multiple cycles of warming and cooling during the past 20 million years,” says McKay.
By doing so, scientists hope to understand how warming oceans may trigger a future ice-sheet collapse – and the implications this may have for rising sea levels, temperature changes and marine life. “It’s clear that warming oceans in West Antarctica are working to melt the ice sheet, but it’s equally important to determine how freshwater from the ice sheet melt affects the ocean. This could include sea ice growth, as well as changing nutrient supplies for plankton, which form the base of the marine ecosystems.”
The global team of geologists and palaeontologists will drill at six key sites in the hope of gaining a clearer picture of how much the West Antarctic Ice Sheet has retreated over time – and how warm the sea was before it began to collapse. “The damage to the Earth’s climate is so significant that we are seeing an accelerating loss of ice today,” McKay says. “However, it may not be too late for the West Antarctic Ice Sheet, because models indicate that a dramatic lowering of carbon emissions may prevent a further decline.”
In January, the 40-year-old sailed from Wellington to the Ross Sea on the JOIDES Resolution, a 140m-long scientific research ship operated by the 23-nation International Ocean Discovery Programme (IODP), of which New Zealand is a member.
It’s one of six expeditions in Southern Hemisphere waters over the next 18 months; Kiwi scientists will be leading five of them. Costing around $120 million, the expeditions are believed to be among the largest international investments in New Zealand science in a single year. “Each country that belongs to the IODP pays a levy, and we’re really fortunate that this large international community has chosen to focus on New Zealand for these six voyages.”
Other expeditions will study the tectonic plate boundary to the east of the North Island, a submarine volcano (underwater vent) north-east of the Bay of Plenty, and sediment from beneath the Tasman Sea that could hold clues to the origins and activity of the Pacific Ring of Fire.
McKay, who contemplated a career as an architect until he realised geology was more fun, has been planning the Antarctic expedition for around seven years, with the help of a Royal Society of New Zealand Fellowship.
He says data from previous drilling expeditions has been used to help model projections identifying the best drilling options.
“This work builds on some of the earliest Antarctic sediment samples, collected in the 70s, which are still proving to be valuable. So what we find on this expedition is likely to inform global research for many years to come.”
This was published in the February 2018 issue of North & South.
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