Peck, V. L. and Hall, I. R. and Zahn, R. and Elderfield, H. (2008) Millennial-scale surface and subsurface paleothermometry from the northeast Atlantic, 55–8 ka BP. Paleoceanography, 23. PA3221. DOI 10.1029/2008PA001631.
Restricted to Registered users only
We present high-resolution records of upper ocean temperatures derived from Mg/Ca ratios of surface-dwelling Globigerina bulloides and subsurface-dwelling Neogloboquadrina pachyderma sinistral and the relative abundance of N. pachyderma sinistral for the period 55–8 ka BP from NE Atlantic sediment core MD01-2461. Millennial-scale temporal variability and longer-term trends in these records enable us to develop a detailed picture of past ocean conditions such as a weakening of thermocline intensity from marine isotope stage 3 (MIS 3) to the last glacial maximum (LGM). The correspondence of all temperature proxies and convergence of paired oxygen isotope (δ 18O) records from both planktonic species implies a breakdown in the thermocline and year-round mixing of the upper water column through the LGM, perhaps related to decreasing insolation and additional cooling in association with the expansion of the circum–North Atlantic ice sheets. Millennial-scale divergence in surface and subsurface temperatures and δ 18O across the last glacial correspond to meltwater release and the development of a strong halocline associated with both Heinrich (H) events and instabilities of the NW European ice sheet. During such episodes, G. bulloides Mg/Ca appears to record ambient, even warming summer sea surface temperatures across H events while the other proxies record maximum cooling.
|Uncontrolled Keywords:||08AREP IA57 2008 P|
|Subjects:||01 - Climate Change and Earth-Ocean Atmosphere Systems|
|Divisions:||01 - Climate Change and Earth-Ocean Atmosphere Systems|
|Journal or Publication Title:||Paleoceanography|
|Depositing User:||Sarah Humbert|
|Date Deposited:||16 Feb 2009 13:03|
|Last Modified:||23 Jul 2013 10:08|
Actions (login required)