Expedition to study climate change
Victoria University of Wellington geologist Dr Rob Mckay is leading an international expedition to Antarctic waters in January to discover how warming oceans will affect the West Antarctic Ice Sheet, and what that could mean for rising sea levels, global weather systems and marine life.
An associate professor at Victoria’s Antarctic Research Centre, Dr McKay will head a 30-member team of scientists from the International Ocean Discovery Programme (IODP) on the JOIDES Resolution, a 140m long scientific research ship operated by the IODP.
“We plan to spend nine and a half weeks down in the outer Ross Sea to drill six geological drill sites—each of which could be up to a kilometre below the sea floor,” said Dr McKay. “We want to understand how the ocean and the ice sheets interact. So what happens when you put warm water next to the ice sheets? Do they melt? If so, how quickly do they melt? And what’s the impact of that melt on the oceans?”
By drilling down so deeply into the sea floor, the team will be able to get a glimpse into the past—up to 20 million years ago—and “greenhouse worlds” that contained the same level of carbon dioxide currently in our atmosphere.
“Using these geological records to see what the planetary response was to the current carbon dioxide levels means we can better understand what the scale of change could be for us, and what the earth is capable of in a warmer world,” added Dr Mckay. If the West Antarctic Ice Sheet were to melt—as it has in the past—the global sea level would rise about 3 metres.
The impact from the collapse of the Eastern Antarctic Ice Sheet would be even more dramatic, as it contains enough ice to cause an estimated 20-metre rise in sea levels. “The consequences of that for coastal living, globally, are obvious, but we’re also trying to understand the implications for the biosphere in the Southern Ocean,” he says.
An important difference between then and now is also the fact that the increase in carbon dioxide levels that took many thousands of years to occur as part of natural cycles, has happened in just a couple of centuries due to human emissions and is continuing. After a hiatus of almost eight years, Dr McKay returns to Antarctica to gather material that is “likely to inform global research for many years to come”.
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