The University of Southampton
University of Southampton Institutional Repository

Letter to Nature. Rapid stepwise onset of Antarctic glaciation and deeper calcite compensation in the Pacific Ocean

Record type: Article

The ocean depth at which the rate of calcium carbonate input from surface waters equals the rate of dissolution is termed the calcite compensation depth. At present, this depth is 4,500 m, with some variation between and within ocean basins. The calcite compensation depth is linked to ocean acidity, which is in turn linked to atmospheric carbon dioxide concentrations and hence global climate1. Geological records of changes in the calcite compensation depth show a prominent deepening of more than 1 km near the Eocene/Oligocene boundary (34 million years ago) when significant permanent ice sheets first appeared on Antarctica, but the relationship between these two events is poorly understood. Here we present ocean sediment records of calcium carbonate content as well as carbon and oxygen isotopic compositions from the tropical Pacific Ocean that cover the Eocene/Oligocene boundary. We find that the deepening of the calcite compensation depth was more rapid than previously documented and occurred in two jumps of about 40,000 years each, synchronous with the stepwise onset of Antarctic ice-sheet growth. The glaciation was initiated, after climatic preconditioning, by an interval when the Earth's orbit of the Sun favoured cool summers. The changes in oxygen-isotope composition across the Eocene/Oligocene boundary are too large to be explained by Antarctic ice-sheet growth alone and must therefore also indicate contemporaneous global cooling and/or Northern Hemisphere glaciation.

Full text not available from this repository.

Citation

Coxall, H.K., Wilson, P.A., Pälike, H., Lear, C.H. and Backman, J. (2005) Letter to Nature. Rapid stepwise onset of Antarctic glaciation and deeper calcite compensation in the Pacific Ocean Nature, 433, (7021), pp. 53-57. (doi:10.1038/nature03135).

More information

Published date: 2005

Identifiers

Local EPrints ID: 14886
URI: http://eprints.soton.ac.uk/id/eprint/14886
ISSN: 0028-0836
PURE UUID: 293c92b5-1700-42ee-ab43-dc69de36ae46

Catalogue record

Date deposited: 17 Mar 2005
Last modified: 17 Jul 2017 16:52

Export record

Altmetrics

Contributors

Author: H.K. Coxall
Author: P.A. Wilson
Author: H. Pälike
Author: C.H. Lear
Author: J. Backman

University divisions


Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×