The Impact of Northern Hemisphere Glaciation on Intermediate and Deep Ocean Circulation

The intensification of Northern Hemisphere Glaciation (iNHG) is a process where much of the Northern Hemisphere was covered in ice for the first time in the Cenozoic. It is the largest secular climate shift over the last 5 Ma.

Understanding the processes that govern this will help to better understand climate dynamics which can prepare us for future climate changes.

Over the iNHG, there is a convergence in water mass properties between the deep and intermediate North Pacific and Atlantic Oceans. This is thought to be due to either North Pacific or Southern Ocean forcings.

This project aims to look at Site 1209 in the Northwest Pacific using trace element analysis to determine the temperature, carbon storage and provenance of water masses overlying the site. This should show how circulation in the North Pacific changed over the iNHG.

Comparison between this site and radiogenic isotope records from Sites 925, 927, and 929 in the mid-Atlantic can be used to infer how connectivity between these two oceans changed over the iNHG.

Finally, through statistical analysis of the number of tephra layers at Sites 981 and 982, this project intends to see how the iNHG affected the rate of volcanism in Iceland.