Millennial-scale surface and subsurface paleothermometry from the northeast Atlantic, 55-8 ka BP
| Type | Article | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Date | 2008-09 | ||||||||
| Language | English | ||||||||
| Author(s) | Peck V. L.1, Hall I. R.1, Zahn R.3, 4, Elderfield H.2 | ||||||||
| Affiliation(s) | 1 : Cardiff Univ, Sch Earth & Ocean Sci, Cardiff CF10 3YE, S Glam, Wales. 2 : Univ Cambridge, Dept Earth Sci, Cambridge CB2 3EQ, England. 3 : Univ Autonoma Barcelona, Dept Geol, Inst Ciencia & Tecnol Ambientals, E-08193 Barcelona, Spain. 4 : Univ Autonoma Barcelona, Dept Geol, Inst Catalana Recerca & Estudis Avancats, E-08193 Barcelona, Spain. |
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| Source | Paleoceanography (0883-8305) (Amer Geophysical Union), 2008-09 , Vol. 23 , N. 3 / PA3221 , P. 1-11 | ||||||||
| DOI | 10.1029/2008PA001631 | ||||||||
| WOS© Times Cited | 55 | ||||||||
| Abstract | 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 (delta O-18) 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 delta O-18 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. | ||||||||
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