Hostname: page-component-cd9895bd7-8ctnn Total loading time: 0 Render date: 2024-12-27T09:26:39.469Z Has data issue: false hasContentIssue false

Glacio-isostasy and Glacial Ice Load at Law Dome, Wilkes Land, East Antarctica

Published online by Cambridge University Press:  20 January 2017

Ian D. Goodwin
Affiliation:
SCAR Global Change Programme, Antarctic CRC, G.P.O. Box 252-80, Hobart, Tasmania 7001, Australia Ian.Goodwin@newcastle.edu.au
Christopher Zweck
Affiliation:
Antarctic CRC, G.P.O. Box 252-80, Hobart, Tasmania 7001, Australia

Abstract

The Holocene sea-level high stand or “marine limit” in Wilkes Land, East Antarctica, reached ∼30 m above present sea level at a few dispersed sites. The most detailed marine limit data have been recorded for the Windmill Islands and Budd Coast at the margin of the Law Dome ice cap, a dome of the East Antarctic Ice Sheet (EAIS). Relative sea-level lowering of 30 m and the associated emergence of the Windmill Islands have occurred since 6900 14C (corr.) yr B.P. Numerical modeling of the Earth's rheology is used to determine the glacio-isostatic component of the observed relative sea-level lowering. Glaciological evidence suggests that most of EAIS thickening occurred around its margin, with expansion onto the continental shelf. Consequently, a regional ice history for the last glacial maximum (LGM) was applied in the glacio-isostatic modeling to test whether the observed relative sea-level lowering was primarily produced by regional ice-sheet changes. The results of the modeling indicate that the postglacial (13,000 to 8000 14C yr B.P) removal of an ice load of between 770 and 1000 m from around the margin of the Law Dome and adjacent EAIS have produced the observed relative sea-level lowering. Such an additional ice load would have been associated with a 40- to 65-km expansion of the Law Dome to near the continental shelf break, together with a few hundred meters of ice thickening on the adjoining coastal slope of the EAIS up to 2000 m elevation. Whereas the observed changes in relative sea level are shown to be strongly influenced by regional ice sheet changes, the glacio-isostatic response at the Windmill Islands results from a combination of regional and to a lesser extent, Antarctic-wide effects. The correspondence between the Holocene relative sea-level lowering interpreted at the margin of the Law Dome and the lowering interpreted along the remainder of the Wilkes Land and Oates Land coasts (105°–160° E) suggests that a similar ice load of up to 1000 m existed along the EAIS margin between Wilkes Land and Oates Land.

Type
Research Article
Copyright
University of Washington

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Andrews, J.T., (1970). A Geomorphological Study of Post-Glacial Uplift with Particular Reference to Arctic Canada.Google Scholar
Cameron, R.L., (1964). Glaciological studies at Wilkes Station, Budd Coast, Antarctica. Mellor, M., Antarctic Snow and Ice Studies Am. Geophys. Union, Washington.136.Google Scholar
Cathles, L.M., (1975). The Viscosity of the Earth's Mantle. Princeton Univ. Press, Princeton.Google Scholar
Clark, J.A., Lingle, C.S., (1979). Predicted relative sea-level changes (18,000 years B.P. to present) caused by late-glacial retreat of the Antarctic Ice Sheet. Quaternary Research 11, 279298.CrossRefGoogle Scholar
Colhoun, E.A., Mabin, M.C.G., Adamson, D.A., Kirk, R.M., (1992). Antarctic ice volume and contribution to sea-level fall at 20,000 yr B.P. from raised beaches. Nature 358, 316319.CrossRefGoogle Scholar
Colhoun, E.A., (1997). A review of geomorphological research in Bunger Hills and expansion of the East Antarctic Ice Sheet during the Last Glacial Maximum. Ricci, C.A., The Antarctic Region: Geological Evolution and Processes Terra Antarctica Publication, Siena.801807.Google Scholar
Delmotte, M., Raynaud, D., Morgan, V., Jouzel, J., (1999). Climatic and glaciological information inferred from air content measurements of a Law Dome East Antarctica ice core. Journal of Glaciology 45, 255263.CrossRefGoogle Scholar
Denton, G.H., Hughes, T.J., (1981). The Last Great Ice Sheets. Wiley, New York.Google Scholar
Fairbanks, R.G., (1989). A 17,000-year glacio-eustatic sea level record: Influence of glacial melting rates on the Younger Dryas event and deep-ocean circulation. Nature 342, 637642.CrossRefGoogle Scholar
GEBCO, (1997). GEBCO Sheet 97.1, compiled by R. L. Fisher of Scripps Institution of Oceanography, and made available through the GEBCO Digital Atlas published by the British Oceanographic Data Centre on behalf of the IOC and IHO.Google Scholar
Goodwin, I.D., (1993). Holocene deglaciation, sea-level change, and the emergence of the Windmill Islands, Budd Coast, Antarctica. Quaternary Research 40, 7080.CrossRefGoogle Scholar
Goodwin, I.D., (1993). Basal ice accretion and debris entrainment within the coastal ice margin, Law Dome, Antarctica. Journal of Glaciology 39, 157166.CrossRefGoogle Scholar
Goodwin, I.D., (1996). A mid- to late Holocene readvance of the Law Dome ice margin, Budd Coast, East Antarctica. Antarctic Science 8, 395406.CrossRefGoogle Scholar
Gore, D.B., Colhoun, E.A., (1997). Regional contrasts in weathering and glacial sediments suggest long term subaerial exposure of Vestfold Hills, East Antarctica. Ricci, C.A., The Antarctic Region: Geological Evolution and Processes Terra Antarctica Publication, Siena.835839.Google Scholar
Harris, P.T., Taylor, F., Domack, E., DeSantis, L., Goodwin, I., Quilty, P.G., O'Brien, P.E., (1997). Glacimarine siliciclastic muds from Vincennes Bay, East Antarctica: Preliminary results of an exploratory cruise in 1997. Terra Antarctica 4, 1120.Google Scholar
Hollin, J.T., (1962). On the glacial history of Antarctica. Journal of Glaciology 4, 173195.CrossRefGoogle Scholar
Hollin, J.T., Cameron, R.L., (1961). I.G.Y. Glaciological work at Wilkes Station, Antarctica. Journal of Glaciology 3, 833842.CrossRefGoogle Scholar
Jouzel, J., Lorius, C., Petit, J.R., Genthon, C., Barkov, N.I., Kotlyakov, V.M., Petrov, V.M., (1987). Vostok ice core: A continuous isotope temperature record over the last climatic cycle (160,000 years). Nature 329, 402408.CrossRefGoogle Scholar
Løken, O., (1959). Evidence of higher sea levels in the Windmill Islands. Cameron, R.L., Wilkes Station Glaciological Data 1957–58.Google Scholar
Martinerie, P., Lipenkov, V.Y., Raynaud, D., Chappellaz, J., Barkov, N.I., Lorius, C., (1994). Air content palaeo record in the Vostok ice core (Antarctica): A mixed record of climatic and glaciological parameters. Journal of Geophysical Research 99, 10,56510,576.Google Scholar
McCleod, I.R., Gregory, C.M., (1966). Geological Investigations along the Antarctic Coast between Longitudes 108°E and 166°E. ANARE Scientific Reports, Series A (111) Geology.Google Scholar
Morgan, P, Bock, Y, Coleman, R, Feng, P, Garrard, D, Johnston, G, Luton, G, McDowall, B, Pearse, M, Rizos, C, Tiesler, R., (1996). A Zero Order GPS Network for the Australian Region, UNISURV S-46. School of Geomatic Engineering, University of New South Wales, Sydney, NSW, Australia.Google Scholar
Morgan, V., Wookey, C.W., Li, J., van Ommen, T.D., Skinner, W., Fitzpatrick, M., (1997). Site information and initial results from deep ice drilling at Law Dome, Antarctica. Journal of Glaciology 43, 310.CrossRefGoogle Scholar
Nakada, M., Lambeck, K., (1988). The melting history of the Late Pleistocene Antarctic ice sheet. Nature 333, 3640.CrossRefGoogle Scholar
Paterson, , (1994). The Physics of Glaciers. 3rd ed, Pergamon, Elmsford, New York.Google Scholar
Peltier, W.R., (1988). 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 non-uniqueness. Quaternary Research 29, 93112.CrossRefGoogle Scholar
Pfitzner, M.L., (1980). The Wilkes Ice Cap Project 1966. ANARE Scientific Reports, Series A (4) Glaciology.Google Scholar
Raynaud, D., Lebel, B., (1979). Total gas content and surface elevation of polar ice sheets. Nature 281, 289291.CrossRefGoogle Scholar
Stillwell, F.L., (1918). The metamorphic rocks of Adelie Land. Scientific Reports, Series A 3, 1524.Google Scholar
Tushingham, A.M., Peltier, W.R., (1991). ICE-3G: A new model of Late Pleistocene deglaciation based upon geophysical predictions of Post-Glacial relative sea level change. Journal of Geophysical Research 96, 44974523.CrossRefGoogle Scholar
Wu, P., (1992). Viscoelastic versus viscous deformation and the advection of prestress. Geophysical Journal International 108, 136143.CrossRefGoogle Scholar
Wu, P., Peltier, W.R., (1983). Glacial isostatic adjustment and the free air gravity anomaly as a constraint on deep mantle viscosity. Geophysical Journal of the Royal Astronomical Society 74, 377449.Google Scholar
Zwartz, D., Lambeck, K., Bird, M., Stone, J., (1997). Constraints on the former Antarctic Ice Sheet from sea-level observations and geodynamic modeling. Ricci, C.A., The Antarctic Region: Geological Evolution and Processes Terra Antarctica Publication, Siena.821828.Google Scholar