Pore fluids and the LGM ocean salinity; reconsidered

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doi: 10.1016/j.quascirev.2016.01.015
Author(s): Wunsch, Carl
Author Affiliation(s): Primary:
Harvard University, Department of Earth and Planetary Sciences, Cambridge, MA, United States
Volume Title: Quaternary Science Reviews
Source: Quaternary Science Reviews, Vol.135, p.154-170. Publisher: Elsevier, International. ISSN: 0277-3791
Note: In English. Includes appendices. 40 refs.; illus., incl. 2 tables, sketch map
Summary: Pore fluid chlorinity/salinity data from deep-sea cores related to the salinity maximum of the last glacial maximum (LGM) are analyzed using estimation methods deriving from linear control theory. With conventional diffusion coefficient values and no vertical advection, results show a very strong dependence upon initial conditions at -100 ky. Earlier inferences that the abyssal Southern Ocean was strongly salt-stratified in the LGM with a relatively fresh North Atlantic Ocean are found to be consistent within uncertainties of the salinity determination, which remain of order ±1 g/kg. However, an LGM Southern Ocean abyss with an important relative excess of salt is an assumption, one not required by existing core data. None of the present results show statistically significant abyssal salinity values above the global average, and results remain consistent, apart from a general increase owing to diminished sea level, with a more conventional salinity distribution having deep values lower than the global mean. The Southern Ocean core does show a higher salinity than the North Atlantic one on the Bermuda Rise at different water depths. Although much more sophisticated models of the pore-fluid salinity can be used, they will only increase the resulting uncertainties, unless considerably more data can be obtained. Results are consistent with complex regional variations in abyssal salinity during deglaciation, but none are statistically significant. Abstract Copyright (2016) Elsevier, B.V.
Year of Publication: 2016
Research Program: ODP Ocean Drilling Program
Key Words: 24 Surficial Geology, Quaternary Geology; Atlantic Ocean; Bermuda Rise; Cenozoic; Cores; Data processing; Digital simulation; Last glacial maximum; Leg 172; Leg 177; Marine sediments; Mathematical models; North Atlantic; Numerical models; ODP Site 1063; ODP Site 1093; Ocean Drilling Program; Paleo-oceanography; Paleosalinity; Pleistocene; Pore water; Quaternary; Sea water; Sediments; South Atlantic; Upper Pleistocene
Coordinates: S495835 S495835 E0055156 E0055156
N334111 N334111 W0573654 W0573654
Record ID: 2017049125
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands