accompanying the Postglacial Transgression). In this paper, data from the 

 northern Great Barrier Reef Province are evaluated in relation to various 

 causes of sea-level change. Emphasis is placed on explaining variations in 

 relative sea-level position by hydro- isostatic theory. Deflexion in the ocean 

 margin 'hinge zone' varies with continental shelf geometry and rigidity of the 

 underlying lithosphere. The fact that the oceanic crust meets the continental 

 crust quite abruptly east of the study areas, dictates that moderately strong 

 flexures occur, and that variations in Holocene hydro- isostatic flexure in the 

 Great Barrier Reef Province are partly explainable in these terms. (Authors). 



342 THOM, B. G., and ROY, P. S. 1985. "Relative Southeast Australia in the 

 Holocene," Journal of Sedimentary Petrology . Vol 55, No. 2, pp 257-264. 



An examination of tide gage records from Newcastle and Syndey showed 

 distinctive, steplike fluctuations in the order of 10 cm, superimposed on a 

 nearly static sea-level trend. Based on annual mean values of sea-level for 

 Syndey and Newcastle, local sea-level trends are more of a response to long- 

 term variations in regional storm patterns and associated climatic events than 

 to global trends in sea level. The authors concluded from available records 

 that the degree of sea-level rise in southeast Australia is smaller than the 

 rates observed in many other parts of the world. (Gorman) 



343 THOMAS, R. H., THOMPSON, D. E., BINDSCHADLER, R. A., and MacAYEAL, D. R. 



1983. "Ice-Sheet Melting and Sea-Level," Proceedings of Coastal Zone '83. 

 Third Symposium on Coastal and Ocean Management , Vol III, pp 2845-2857. 



The major potential for sea- level rise during periods of climatic warm- 

 ing is by melting of polar ice. At present, there is considerable summer 

 melting from parts of the Greenland ice sheet, and this would increase under 

 warmer conditions. However, there is little surface melting in Antarctica, 

 and anticipated climatic warming would cause melting only in low-lying area. 

 Nevertheless, this may weaken the large, floating ice shelves into which flows 

 most of the ice draining from Antarctica. A probable result would be signifi- 

 cantly increased ice-drainage rates and more Antarctic icebergs. Portions of 

 the ice sheet that rest on continental shelf could become unstable and col- 

 lapse. If this happens, sea- level increase would be slow at first but would 

 accelerate rapidly once the collapse became irreversible. 



Although definitive predictions of ice sheet response to prescribed cli- 

 matic warming cannot yet be made, we are trying to estimate probable bounds to 

 the response of major ice drainage basins. We use a very simple model to de- 

 scribe the glacier response to changes in the ice shelves wrought by a warming 

 climate. Climate parameters are from the GISS simulations, and related ocean 

 characteristics are from a study by A. Gordon. (Authors) . 



158 



