A COMPARISON OF LAND-USE AND GLACIAL CONTROLS ON EROSION IN THE NORTHEASTERN UNITED STATES

Anthropogenic land-use changes related to deforestation and agriculture have influenced erosion rates and processes in the northeastern United States (NEUS) since European settlement. Glacial history may also have an impact on rates of erosion, as glaciation results in the localized deposition of erosion-resistant materials like tills and provides accommodation space for eroded sediment in lakes and wetlands. While land-use history is consistent across the NEUS, the glacial legacy in the northern part of the region has the potential to reduce sediment supply and mobilization. We compare erosion rates between the glaciated and unglaciated NEUS, across various timescales, to test the hypotheses that (1) historic to modern erosion rates are higher than background rates across the NEUS and (2) erosion rates south of the Pleistocene glacial limit are higher than those north of it. We mine erosion rates and sediment yields from existing literature, using records from thermochronometry, cosmogenic nuclide concentrations in stream sediment, lake and reservoir sedimentation, and stream gauging. Preliminary results show no significant difference between modern and geologic erosion rates. Further, rates in the formerly glaciated NEUS are about 30 percent lower than the unglaciated region over multiple timescales, suggesting that the regional signal of Pleistocene-Holocene climate change may be more significant than that of land-use change.