Lithospheric Thickness, Antarctic Deglaciation History, and Ocean Basin Discretization Effects in a Global Model Of Postglacial Sea Level Change: a Summary of Some Sources of Nonuniqueness

• Published in: Quaternary Research
• Main Author: Peltier, W. R.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1988
• Subjects: Antarc*; Antarctic; Antarctica; West Antarctica
• Online Access: http://dx.doi.org/10.1016/0033-5894(88)90054-3; http://api.elsevier.com/content/article/PII:0033589488900543?httpAccept=text/xml; http://api.elsevier.com/content/article/PII:0033589488900543?httpAccept=text/plain; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0033589400018810

The global model of postglacial relative sea level variations that has been developed over the past decade is employed to investigate the constraints that it may be invoked to place on the timing of the deglaciation of West Antarctica. The analyses presented here confirm the suggestion of P. Wu and W. R. Peltier (1983, Geophysical Journal of the Royal Astronomical Society 74 , 377–450) that the model of this event employed in J. A. Clark and C. S. Lingle (1979 Quaternary Research 11 , 279–298) may be simply modified to rectify the misfits between theory and observation that are otherwise obtained at Southern Hemisphere sites. A large number of Southern Hemisphere relative sea level data are shown to require that the retreat of Antarctic ice substantially lagged the retreat of Northern Hemisphere ice if the deglaciation of Antarctica was abrupt. The time of onset of Antarctic deglaciation is thereby shown to coincide with the time of most rapid Northern Hemisphere deglaciation. Sensitivity tests are performed which demonstrate that this result is relatively insensitive to the discretization employed to represent the ocean basins; the only exception to this general rule obtains at some coastal sites at which a trade-off is revealed between the delay of West Antarctic melting and the thickness of the lithosphere required to reconcile the observed local variations of relative sea level. At such sites, which are all in the far field of the ice sheets, some attention must be paid to the accuracy of the local finite element representation of the oceans and to the details of the Antarctic deglaciation history.