A NEW SEA-LEVEL CURVE FROM NOVA-SCOTIA - EVIDENCE FOR A RAPID ACCELERATION OF SEA-LEVEL RISE IN THE LATE MIDHOLOCENE

A new late Holocene sea-level curve is presented from the Atlantic coa st of Nova Scotia. Contrary to earlier data from the same area, this c urve starts at 4400 sidereal years before present (BP) and shows a rap id acceleration between 4400 and 3800 BP, which coincides with a simil ar acceleration already reported from the Northumberland Strait (Nova Scotia) and an oscillation observed in South Carolina. Comparing the t wo Nova Scotia curves suggests that the acceleration lasts just over 1 000 years and has a vertical extent of 10 m. One puzzling fact is that the 10 m vertical extent in Nova Scotia is 8 m more than the same eve nt measured in South Carolina and it cannot be accounted for simply by postglacial isostatic depression, since that occurs on a much longer time scale. A closer examination of most of the sea-level curves from northeastern North America reveals that either the record is missing f rom this interval or it is inconsistent. We suggest that this accelera tion is part of a global response that coincides with the end of the m id-Holocene warming period, possibly indicating a lag response between warming and ice melt.