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Department of Earth Sciences


Researchers explore global ocean dead zones and hot greenhouse climate during the age of dinosaurs

(29 November 2017)

An international team of scientists aboard research vessel JOIDES Resolution have just completed an eight-week voyage studying Australia’s climate and tectonics during the Cretaceous Period (the last age of the dinosaurs). 30 scientists from 15 countries, collected samples from deep beneath the ocean floor at five sites in water depths of 860-3850 metres mainlyin the Mentelle Basin off south-west Australia.

The expedition was jointly led by Prof. Richard Hobbs from Durham and Dr Brian Huber from the Smithsonian in Washington, USA. Richard Hobbs has been working on this project for over five years from its original conception to this now successful expedition, together with others from this Department including Darren Gröcke, Colin Sargent, Dominic Maloney and, most recently, Dimitrios Michelioudakis. During the expedition, Richard Hobbs, was responsible for selecting the sites for coring and predicting the depths to the geological targets. Then working with the drillers to ensure the best recovery of core was achieved over the different lithologies encountered, the scientists to collate the on-board analyses, and finally with the IODP staff to compile the expedition report.

A total 2.5 kilometres of sediment was cored from layers that provide a near continuous record of how the geography, volcanism, oceans and climate of the southern margin of Australia changed over the past 140 million years. The cores record the progressive separation of Australia from India and Antarctica, and the subsequent evolution of Earth’s climate. Of particular interest are the global ocean dead zones, known as Oceanic Anoxic Events (OAEs). They occurred during the Cretaceous Period when significant volumes of the oceans became starved of oxygen and large swaths of the seafloor became devoid of animal life. It is hoped the excellent core recovery over the OAE intervals that we acheived during the expedition will help resolve many of the questions over the what are the drivers for these events and how life re-established itself within these zones.