1. Research School of Earth Sciences, Australian National University, Canberra, ACT0200, Australia
2. Department of Geology, Australian National University, Canberra, ACT 0200, Australia
3. Department of Nuclear Physics, Research School of Physical Sciences and Engineering, Australian National University, Canberra, ACT 0200, Australia.

The Last Glacial Maximum (LGM) is an important period in recent Earth history when ice sheets covered large areas in northern latitudes and global temperatures were significantly lower than today. The volumes and geographic distribution of the ice during the Last Glacial Maximum and the subsequent late-glacial stage remain uncertain despite recent progress in understanding the evolution of the late Pleistocene ice sheets. Reconstructions of these quantities are important constraints to the understanding of the global atmosphere-ocean system during a glacial cycle. Few direct estimates of these volumes, timing and rates exist, and the available information rests largely on indirect measurements, such as the oxygen isotope signal of marine sediment cores.

New sea-level data have been obtained from the tectonically stable Bonaparte Gulf, Northwestern Australia, from shallow-water sediment cores using sedimentological, micropalaeontological and 14C AMS dating methods. The observations indicate that locally sea-level stood at a nearly constant level of —120 m from 18 to 16.5 14C ka BP. This was followed by a very rapid rise of about 15 m within 500 14C years, followed by the less-rapid Late glacial sea-level rise. At the LGM, grounded ice on the continental margins and seas, is 52.5 x 10^6 km^3 greater than the present value and volume of the ice discharged amounted to about 5.2 x 10^6 km^3. We conclude that the LGM terminated at 16.5 14C BP with a rapid discharge of continental ice into the oceans.