MONITORING SUBSURFACE AND SURFACE PROCESSES AT MCINTYRE’S BLUFF, STERLING, NY, USING 3D MODELING AND GEOPHYSICAL METHODS

Much of Lake Ontario shoreline between Fair Haven, NY and West Nine Mile Point is characterized by bluffs composed of unconsolidated glacial sediment. These bluffs are particularly prone to erosion, causing rapid retreat of the shoreline. In order to constrain the impacts of various shoreline processes on erosion, biweekly surveys of McIntyre’s Bluff in Sterling, NY are being conducted using a DJI Mavic 2 Pro UAV. Software that harnesses the principles of Structure From Motion allows for high-definition 3D models to be constructed from digital UAV images of the bluffs. To quantify erosion rate over time, the 3D models are compared and differenced from one another using Cloud Compare software. Additionally, data collected using exploratory instrumentation such as ground penetrating radar and electrical resistivity has helped with understanding how the surface geology at the bluffs relates to the subsurface. Continued long-term monitoring using UAV imagery and geophysical instrumentation will help demystify the impacts of local climatic variations and erosional processes, and their influences on the stability of the bluffs. Through monthly comparisons of datasets, the erosional rate at the bluff surface will be accurately quantified, and the relationship between surface and subsurface geology and lake effect snow, rain, ice, lake level, wind, and other possible sources for weathering will be more accurately characterized.