Drill team probes sea changes
The drilling ship will take cores from a
sedimentary basin, helping the team to
discover whether global climate change
or local tectonic forces have had a greater
effect on sea levels.
Image: iStockphoto

Two Australian scientists will join an international group of researchers on a voyage to investigate changing sea levels.

They will be part of the research drilling ship JOIDES Resolution expedition to the Canterbury Basin off New Zealand.

The ship is part of the Integrated Ocean Drilling Program (IODP), which is the world’s largest multinational geoscience research program.

The JOIDES Resolution can take continuous sediment or rock cores in most water depths and up to 1500 m below the sea bed. Deepwater drilling can be likened to drilling with a string of spaghetti from the top of the Empire State building.

The ship is presently in Townsville replenishing supplies after a similar expedition off Japan to the Shatsky Rise.

James Cook University’s Professor Bob Carter and Associate Professor Simon George from Macquarie University will be joining the ship, which is expected to leave Townsville early next week for the two-month expedition to drill the Canterbury Basin east of New Zealand’s South Island.

“This expedition will investigate the relative importance of global climate change versus local tectonic forces, on changing sea level and sedimentary processes during the last 30 million years,” Professor Neville Exon from The Australian National University said.

Professor Exon manages the Australian office of the Australian New Zealand consortium ANZIC, which is part of the world-wide IODP. The Australian involvement is supported by the Australian Research Council, 14 universities and CSIRO, ANSTO and AIMS and is based at ANU.

“This sedimentary basin is a good place to investigate global sea level changes, which have frequently amounted to 100 metres in the past,” Professor Exon said. “An understanding of past sea level changes helps geologists to better interpret sedimentary strata around the world, which is important for resource assessment.

“Such studies also help scientists improve predictions of possible future changes in sea level and is related to the current debate over the impacts of CO2-induced global warming.”

Professor Carter said that previous seabed cores from east of NZ’s South Island have revealed a close match between climate change in New Zealand and Antarctica, with their glaciers expanding and shrinking in concert.

“This means that in the past climate has changed almost synchronously across about 45 degrees of latitude, and is an important step towards demonstrating the truly global nature or natural climate oscillations” Professor Carter said.

Associate Professor George said that he was looking forward to helping analyse and understand the sediments that will be drilled.

“Some of them will be organic-rich, and they will provide a fabulous repository of information about past climate change and depositional environments,” he said.

“I am also looking forward to working as part of a 35-strong scientific team for eight weeks - quite different to my normal research and teaching role at Macquarie University.”

Editor's Note: Original news release can be found here .