Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.
The Salinity, Temperature, and 18O of the Glacial Deep Ocean
Jess F. Adkins,1*Katherine McIntyre,1Daniel P. Schrag2
We use pore fluid measurements of the chloride concentration and
the oxygen isotopic composition from Ocean Drilling Programcores to
reconstruct salinity and temperature of the deep oceanduring the Last
Glacial Maximum (LGM). Our data show that thetemperatures of the deep
Pacific, Southern, and Atlantic oceansduring the LGM were relatively
homogeneous and within error ofthe freezing point of seawater at the
ocean's surface. Our chloridedata show that the glacial
stratification was dominated by salinityvariations, in contrast with
the modern ocean, for which temperatureplays a primary role. During
the LGM the Southern Ocean containedthe saltiest water in the deep
ocean. This reversal of the modernsalinity contrast between the North
and South Atlantic impliesthat the freshwater budget at the poles must
have been quite different.A strict conversion of mean salinity at the
LGM to equivalentsea-level change yields a value in excess of 140 meters. However,the storage of fresh water in ice shelves and/or
groundwater reservesimplies that glacial salinity is a poor predictor
of mean sealevel.
1 MS 100-23, Department of Geological and
Planetary Sciences, California Institute of Technology, Pasadena, CA
91125, USA.
2 Department of Earth and Planetary
Sciences, Harvard University, Cambridge, MA 02138, USA.
*
To whom correspondence should be addressed. E-mail:
jess{at}gps.caltech.edu
18O of the Glacial Deep Ocean
