Spatio-Temporal Variability in Benthic δ13c Across the Last Deglaciation

Abstract:

Ocean circulation changes during the last glacial termination played an important role in atmospheric CO₂ rise and millennial-scale climate change. These circulation changes can be reconstructed using benthic δ¹³C from Cibicidoides wuellerstorfi as a proxy for deep water geometry and ventilation. Here we analyze spatio-temporal variability in benthic δ¹³C across the deglaciation using data from ~90 core locations (70 from the Atlantic). We reconstruct patterns of δ¹³C change in 1-kyr timeslices from 2-24 kyr ago. Principal component analysis reveals the primary modes of deep water circulation change and their links to millennial-scale climate change. 3D visualization tools assist in the interpretation of benthic δ¹³C spatial patterns with respect to complex basin geometry (e.g. East vs. West Atlantic). Additionally, we present regional δ¹³C stacks that improve the signal-to-noise ratio for estimates of the mean δ¹³C change in different water masses through time.