Horizontal-to-Vertical Spectral Ratio (HVSR) Measurements and Depth to Bedrock Estimates along the Salmon River Corridor from the Adirondack Foothills to the St. Lawrence Lowlands, Franklin County, New York, 2018-2023

This data release contains 22 horizontal-to-vertical spectral ratio (HVSR) seismic measurements at 21 sites in Franklin County, New York. The HVSR passive seismic method (Lane and others, 2008; Fairchild and others, 2013) is a non-invasive and cost-effective technique for estimating the thickness of unconsolidated sediments over bedrock. This technique uses a single broadband three-component (x, y, and z directions) seismometer to record ambient seismic noise. The ratio of the averaged horizontal (x, y) to vertical (z) frequency spectrum is used to produce a spectral ratio curve and determine a site’s peak resonant frequency. This frequency can be empirically related to sediment thickness using average local sediment shear-wave velocity or using power-law regression analysis calibrated with local site of known depths to bedrock (Ibs-von Seht and Wohlenberg, 1999; Lane and others, 2008; Chandler and others, 2014; Johnson and Lane, 2016). Data were collected at each site for 30 minutes using a Tromino Model TEP-3C three-component seismometer. Raw and processed HVSR data for each HVSR measurement are presented in the attached files. The HVSR data-collection sites are designated by a county sequential numbering systems (FHVSR1, FHVSR2, FHVSR3, etc. where “F” indicates Franklin County).