GLACIATION AND SEA-LEVEL CHANGE FOR IRELAND AND THE IRISH SEA SINCE LATE DEVENSIAN MIDLANDIAN TIME/

The sea-level change around the coast of Ireland and the Irish Sea for the past 20 000 years is primarily the combined result of the glacio- isostatic adjustment of the crust to the removal of ice over the Briti sh Isles and the total eustatic change from the global ice sheets. How ever, the isostatic effects due to the removal of ice from northern Eu rope and North America and the addition of meltwater into the oceans a lso make a significant contribution. Predictions of sea-level change, based on glacio-hydro-isostatic models are compared with observations to constrain the ice volume over Ireland at the time of the last glaci al maximum and the maximum ice height appears to have been of the orde r of 600 m. The models predict well the spatial variability in sea-lev el change observed across the region for Holocene and Lateglacial time , with levels above present being predicted only for northeastern Irel and and north of about Morecambe Bay. The models do not support sugges tions that Lateglacial levels along the east coast of Ireland or the c oast of Wales were 50-150 m above their present levels. Consistent mod els that would produce such large Lateglacial highstands are incompati ble with all other sea level and glacial evidence for the British Isle s. Palaeobathymetry and palaeoshoreline reconstructions for the Irish Sea indicates that a tenuous landbridge between Britain and Ireland de veloped only across the Celtic Sea, between about 18 000 and 14 000 ye ars BP.