Open AccessTiming of meltwater pulse 1a and climate responses to meltwater injections
Author(s) -
Stanford Jennifer D.,
Rohling Eelco J.,
Hunter Sally E.,
Roberts Andrew P.,
Rasmussen Sune O.,
Bard Edouard,
McManus Jerry,
Fairbanks Richard G.
Publication year - 2006
Publication title -
paleoceanography
Language(s) - English
Resource type - Journals
eISSN - 1944-9186
pISSN - 0883-8305
DOI - 10.1029/2006pa001340
Subject(s) - meltwater , younger dryas , deglaciation , geology , oceanography , north atlantic deep water , ice core , climatology , glacial period , thermohaline circulation , climate change , holocene , paleontology
The temporal relationship between meltwater pulse 1a (mwp‐1a) and the climate history of the last deglaciation remains a subject of debate. By combining the Greenland Ice Core Project δ 18 O ice core record on the new Greenland ice core chronology 2005 timescale with the U/Th‐dated Barbados coral record, we conclusively derive that mwp‐1a did not coincide with the sharp Bølling warming but instead with the abrupt cooling of the Older Dryas. To evaluate whether there is a relationship between meltwater injections, North Atlantic Deep Water (NADW) formation, and climate change, we present a high‐resolution record of NADW flow intensity from Eirik Drift through the last deglaciation. It indicates only a relatively minor 200‐year weakening of NADW flow, coincident with mwp‐1a. Our compilation of records also indicates that during Heinrich event 1 and the Younger Dryas there were no discernible sea level rises, and yet these periods were characterized by intense NADW slowdowns/shutdowns. Clearly, deepwater formation and climate are not simply controlled by the magnitude or rate of meltwater addition. Instead, our results emphasize that the location of meltwater pulses may be more important, with NADW formation being particularly sensitive to surface freshening in the Arctic/Nordic Seas.