USING PASSIVE SEISMIC SURVEYS TO ESTIMATE DEPTH TO BEDROCK AND BURIED TOPOGRAPHIC FEATURES IN CAYUGA COUNTY, NY

The New York State Geological Survey has begun a test project using horizontal to vertical spectral ratio surveys (HVSR) to estimate the thickness of the glacial drift and unconsolidated sediments over bedrock as an additional non-invasive geophysical method to characterize geological frameworks. This method shows promise as a valuable technique to assist with reconstruction of New York’s Quaternary history. We utilize a Tromino tromometer and Grilla software by Micromed s.p.a to gather and process HVSR surveys. The initial project involves gathering HVSR readings from verified well bores with depth to bedrock recorded to generate calibration curve for the region of interest. Initial surveys are latitudinal transects of 10 to 15 km in length at a spacing of 1 km between each reading and subsequent readings of closer spacing will be carried out to refine the proposed subsurface model generated from the surveys. Recent field mapping efforts in the Finger Lakes region of New York State as part of our STATEMAP and Great Lakes Geological Mapping Coalition projects have highlighted a need for further understanding of the bedrock topography buried by glacial advances into central New York State. Understanding these unidentified sub-surface features will lead to better understanding of groundwater resources as well as help locate areas to explore for older sediments that could provide a glimpse into chronology, paleoclimates and paleo ecosystems.