Late Quaternary Sea Level and Coastal Evolution in the Western Gulf of Maine

Walter Barnhardt
Chief Scientist

Woods Hole Science Center
United States Geological Survey

Friday, Nov. 5, 2010, 11:55am
Chase 130

The inner continental shelf of the western Gulf of Maine has been shaped by a complicated history of relative sea level (RSL). After deglaciation of the region, isostatic rebound caused RSL to fall to a lowstand depth of 50-60 m at approximately 12,500 cal yr B.P. RSL then rose at highly variable rates to its present elevation, driving the shoreline across wide areas of the inner shelf. Details of the transgression remain elusive but new geophysical data (swath bathymetry, sidescan sonar and subbottom profiling), bottom samples and cores are revealing the geomorphic and stratigraphic record generated by these RSL changes. Reconstructing coastal evolution in the region is critical to understanding potential shoreline responses to variations in future RSL rise and sediment supply that might accompany climate change.