@article{Wilson:2014:10.1002/2014PA002674, author = {Wilson, DJ and Crocket, KC and van, de Flierdt T and Robinson, LF and Adkins, JF}, doi = {10.1002/2014PA002674}, journal = {Paleoceanography}, pages = {1072--1093}, title = {Dynamic intermediate ocean circulation in the North Atlantic during Heinrich Stadial 1: A radiocarbon and neodymium isotope perspective}, url = {http://dx.doi.org/10.1002/2014PA002674}, volume = {29}, year = {2014} }
TY - JOUR AB - The last deglaciation was characterized by a series of millennialscale climate events that have been linked to deep ocean variability. While often implied in interpretations, few direct constraints exist on circulation changes at middepths. Here we provide new constraints on the variability of deglacial middepth circulation using combined radiocarbon and neodymium isotopes in 24 North Atlantic deepsea corals. Their aragonite skeletons have been dated by uraniumseries, providing absolute ages and the resolution to record centennialscale changes, while transects spanning the lifetime of a single coral allow subcentennial tracer reconstruction. Our results reveal that rapid fluctuations of water mass sourcing and radiocarbon affected the middepth water column (1.7–2.5 km) on timescales of less than 100 years during the latter half of Heinrich Stadial 1. The neodymium isotopic variability (−14.5 to −11.0) ranges from the composition of the modern northernsourced waters towards more radiogenic compositions, suggesting the presence of a greater southernsourced component at some times. However, in detail, simple twocomponent mixing between wellventilated northernsourced and radiocarbondepleted southernsourced water masses cannot explain all our data. Instead, corals from ~15.0 ka and ~15.8 ka may record variability between southernsourced intermediate waters and radiocarbondepleted northernsourced waters, unless there was a major shift in the neodymium isotopic composition of the northern endmember. In order to explain the rapid shift towards the most depleted radiocarbon values at ~15.4 ka, we suggest a different mixing scenario involving either radiocarbondepleted deep water from the GreenlandIcelandNorwegian Seas or a southernsourced deep water mass. Since these middepth changes preceded the BollingAllerod warming and were apparently unaccompanied by changes in the deep Atlantic, they may indic AU - Wilson,DJ AU - Crocket,KC AU - van,de Flierdt T AU - Robinson,LF AU - Adkins,JF DO - 10.1002/2014PA002674 EP - 1093 PY - 2014/// SN - 0883-8305 SP - 1072 TI - Dynamic intermediate ocean circulation in the North Atlantic during Heinrich Stadial 1: A radiocarbon and neodymium isotope perspective T2 - Paleoceanography UR - http://dx.doi.org/10.1002/2014PA002674 UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000346489000006&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202 UR - https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2014PA002674 UR - http://hdl.handle.net/10044/1/20096 VL - 29 ER -
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