Seminar talk: Regional patterns of surface reservoir age changes and iceberg discharges across the North Atlantic over the last 40 thousand years

Abstract:

To date, the rapid changes in climate and ocean circulation observed in marine-sediment and ice cores over the last glacial period and deglaciation are still not fully explained. One obstacle hindering progress in our understanding of the interactions between past ocean circulation and climate changes is the difficulty to accurately date marine cores.

I will present the approach we have adopted to establish a set of consistently dated Atlantic sediment cores from 70°N to 50°S, over the last 40 ky. This first set of consistently dated marine sediment cores enables one to evaluate leads/lags between circulation and climate changes over vast regions of the Atlantic Ocean.

I will show that coherent patterns of surface reservoir ages emerge in certain regions.

I will also show that Ice Rafted Detritus (IRD) records are essentially local signals. Importantly, the onset of the coolings associated with Greenland glacials leads the onset of IRD deposition in only one region, whereas it is synchronous with the onset of IRD deposition over most of the North Atlantic.

Claire Waelbroeck

Short biography:

Senior Research Scientist at CNRS

LOCEAN, Sorbonne Université-CNRS, Paris, France

Research interests: links between changes in climate and ocean circulation, past and present.

Arranged date for the seminar talk: Oct 25, 2021 at 14:15 PM

Bjerknes lecture room 4020, Jahnebakken 5