Ocean mixing and ice-sheet control of seawater 234 U/ 238 U during the last deglaciation

• DOI: 10.1126/science.aag1015
• Publication Date: 2016-10-07T02:58:50Z
• Authors: Tianyu Chen; Laura F. Robinson; Matthew P. Beasley; Louis M. Claxton; Morten B. Andersen; Lauren J. Gregoire; Jemma Wadham; Daniel J. Fornari; Karen S. Harpp
• Keywords: Deglaciation

Seawater 234U/238U provides global-scale information about continental weathering and is vital for marine uranium-series geochronology. Existing evidence supports an increase in since the last glacial period, but timing amplitude of its variability has been poorly constrained. Here we report two seawater records based on well-preserved deep-sea corals from low-latitude Atlantic Pacific Oceans. The started to before major sea-level rise overshot modern value by 3 per mil during early deglaciation. Deglacial converged with that after abrupt resumption meridional overturning. We suggest ocean mixing deglacial release excess 234U enhanced subglacial melting Northern Hemisphere ice sheets have driven observed evolution.