Plumbing the depths of Zealandia’s ocean

One of the world's top scientific research ships will next week start a series of expeditions in the seas around New Zealand probing some of the twenty-first century's big earth science questions.

Map of IODP sites
Left: Map of IODP sites. Right: JOIDES Resolution (Credit: IODP).

The 140 metre-long JOIDES Resolution, operated by the 23-nation International Ocean Discovery Program (IODP), will undertake six expeditions totalling about 18 months and involving teams of scientists from all over the world.

New Zealand scientists will lead five of the expeditions. Victoria University of Wellington researchers, Professor Rupert Sutherland and Dr Rob McKay, are each involved in leading an expedition.

Many other Kiwi scientists are involved, either as part of the shipboard science teams or as shore-based researchers.

Each two-month long voyage will have a different focus ranging from the forces that generate earthquakes on the tectonic plate boundary to the east of the North Island to probing the inside workings of a submarine volcano northeast of the Bay of Plenty.

Seafloor study sites have been carefully chosen to yield optimum results for scientific knowledge while being safe for the environment. An independent panel stringently reviews each site to ensure expeditions can be undertaken safely and with minimal environmental impact.

Overall, the voyages represent an international investment in science of around $120 million and will bring close to 200 scientists into the region to undertake research that will continue well beyond the expeditions. The entire project is believed to be the largest project-specific international investment in New Zealand science in a single year ever.

The JOIDES Resolution will make port calls in Auckland and Wellington, giving the public opportunities to tour this state-of-the-art floating laboratory.

Four of the expeditions will have New Zealand outreach specialists on board to provide opportunities for the public to interact with the scientists and keep track of the expedition’s progress through online blogs and live video feeds.

The first expedition, starting next week, is co-lead by Victoria's Professor Rupert Sutherland. The expedition will drill six boreholes in the Tasman Sea to retrieve seafloor sediment cores and investigate the relationships between tectonics and global climatic changes around 50 million years ago. This was a time of high atmospheric carbon dioxide levels when temperatures were 10 degrees warmer than the present day.

Scientists believe sediment cores from the beneath the Tasman Sea will hold clues to massive changes in tectonic forces that formed the ‘Pacific Ring of Fire’ and shaped our mostly submerged continent of Zealandia.

The researchers are also interested in finding out if these tectonic changes influenced the flow of ocean currents, which may help to explain the pronounced warming of seas around New Zealand at this time.

An expedition to the Ross Sea, co-lead by Victoria's Dr Rob McKay and starting in January 2018, will probe the seafloor off the Ross Ice Shelf to improve the understanding of the stability of the West Antarctic Ice Sheet through multiple cycles of warming and cooling during the past 20 million years.

The large volume of new scientific knowledge acquired during the six voyages is likely to resonate among the international science community for decades to come.

New Zealand participates in IODP as part of the Australia and New Zealand IODP consortium. To find out more about IODP and upcoming expeditions, visit https://geodiscovery.gns.cri.nz/

For more follow the JOIDES Resolution journey see the team's website and Facebook page.