Low-Latitude Paleoceanography and Phytoplankton Productivity Through the Eocene/Oligocene Transition (IODP Expedition 320)

Lead Research Organisation: University College London
Department Name: Earth Sciences


The current polar ice-sheet dominated planet that we live on is not typical of most of our planet's history. The current phase of ice-sheet growth on Antarctica began around 23 million years ago (an interval known as the Eocene/Oligocene boundary transition). This switch from warm, ice-free climates to cooler, glacial climates was a profound event but the reasons why it happened are still unclear. One good explanation for this switch, which has support from both geological observations and climate models, is that atmospheric CO2 dropped low enough to cool the climate and to initiate ice-growth on the Antarctica continent. This decline in CO2 may have occurred through enhanced weathering processes or through the increased activity of oceanic plankton. An increase in the productivity of oceanic plankton has been documented from around Antarctica at this time, but we do not know whether this occurred over wider areas of the world ocean, and in particular in the largest oceanic habitat, the Pacific. This project will investigate whether this plankton productivity trigger occurred in the Equatorial Pacific at the Eocene/Oligocene boundary, by examining new sediment cores that will be drilled by the Integrated Ocean Drilling Program in March - May 2009. The Principal Investigator and named PDRA are both Shipboard Scientists on this Expedition 320 and will examine the cores as soon as they are recovered. By quantifying the abundances of the plankton fossils and examining their composition, we will be able to determine the levels of productivity and assess whether Pacific plankton may have contributed to global CO2 drawdown and ultimately to the climate transition that occurred at this time.


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Description Research is currently being readied for publication. At least two papers are planned for 2018. Key findings include the documentation of plankton extinctions and global population shifts associated with climate cooling and ocean circulation change as climate switched from greenhouse to icehouse mode around 33 million years ago.
Exploitation Route The integration of records from different ocean basins will result in a more comprehensive understanding of the response of oceanic ecosystems to significant and rapid climate change.
Sectors Education,Energy,Environment

Description Investigating the history of climate and life through deep sea drilling 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Much of our modern understanding of ocean and climate history comes from the study of deep-sea drill cores. Over the last 50 years, starting with early attempts to drill to the Moho, Deep Sea Drilling Project (DPDP), Ocean Drilling Program (ODP) and most recently Integrated Ocean Drilling Program (IODP) have brought together scientists from 24 countries to study all aspects of ocean history, and collectively this ranks as one of most significant scientific endeavours ever. The talk will provide a glimpse of life onboard the latest IODP drill ship, the JOIDES Resolution, describing the work carried out by around 100 international scientists, technicians and crew during two recent expeditions, working 12 hours a day for two months. The Pacific and Atlantic expeditions IODP Exp. 320 (March-May 2009) and 342 (June-July 2012) both focused on Paleogene science objectives, particularly the interval when climate switched from very warm Eocene 'greenhouse' conditions to the glacial climates of the Oligocene, but, as always, many surprises were encountered along the way, including beautiful examples of impact ejecta beds at the Cretaceous/Tertiary boundary and black shales of the Cretaceous. Although work is ongoing after both expeditions, I will present some of our new findings on the climate and evolutionary history of the Paleogene interval.

Public talk presented at the Festival of Geology, organised by the Geologist's Association
Year(s) Of Engagement Activity 2012
URL http://www.rockwatch.org.uk/docs/festival-of-geology-2012v2.pdf