On May 10, 2017 a land-based seismic survey was collected to obtain a shear- wave velocity (Vs) and compressional velocity (Vp). The Vs was used for estimating with the HVSR data to determine the depth to rock. A secondary objective was to obtain Vs and Vp measurements of the overburden sediments at the toe of the impoundment and adjacent to the stream for geotechnical applications. Four collections were made with a 34.5-m long array of 48 electrodes with one vertical and one horizontal phone every 1.5 m along the survey line. A hammer and two strike plates were used to generate the compressional and shear-wave sound sources.

The horizontal-to-vertical spectral ratio (HVSR) method is a passive seismic technique that uses a three-component seismometer to measure the vertical and horizontal components of ambient seismic noise. Seismic noise in the range of ~0.1 to 1 Hertz (Hz) is caused by ocean waves, large regional storms, and tectonic sources. A resonance frequency (f0) is induced in the unconsolidated when there is a substantial contrast (greater than 2:1) in shear-wave acoustic impedance between the overburden and the bedrock. The f0 is determined from the analysis of the spectral ratio of the horizontal and vertical components of the seismic data. The thickness of the overburden can be related to the f0. In general, lower f0 relates to thicker sediments, and higher f0 relates to relatively thinner overburden. At the former Callahan MIne site the resonance frequency can be related to the depth of the overburden using an average shear-wave velocity that is measured or estimated from locations where there is a known depth to rock and/or using a direct measurement of the shear-wave velocity.

The horizontal-to-vertical spectral ratio (HVSR) method is a passive seismic technique that uses a three-component seismometer to measure the vertical and horizontal components of ambient seismic noise. Seismic noise in the range of ~0.1 to 1 Hertz (Hz) is caused by ocean waves, large regional storms, and tectonic sources. A resonance frequency (f0) is induced in the unconsolidated when there is a substantial contrast (greater than 2:1) in shear-wave acoustic impedance between the overburden and the bedrock. The f0 is determined from the analysis of the spectral ratio of the horizontal and vertical components of the seismic data. The thickness of the overburden can be related to the f0. In general, lower f0 relates to thicker sediments, and higher f0 relates to relatively thinner overburden. At the former Callahan MIne site the resonance frequency can be related to the depth of the overburden using an average shear-wave velocity that is measured or estimated from locations where there is a known depth to rock and/or using a direct measurement of the shear-wave velocity.

In June 2018, U.S. Geological Survey in cooperation with the U.S. Environmental Protection Agency (EPA) collected geophysical measurements to help evaluate the suitability of a proposed landfill site for disposing mine-waste materials in Fredericktown, MO. Shear-wave (Vs) refraction surveys were collected to measure the shear-wave velocity of the subsurface, which can be used for estimating the depth to rock with the horizontal-to-vertical spectral ratio (HVSR) passive seismic reconnaissance method. A secondary objective was to determine the depth of interfaces for comparison to the resistivity surveys and frequency domain electromagnetic profiles.

VS30, the time-averaged shear-wave velocity (VS) to a depth of 30 meters, is a key index adopted by the earthquake engineering community to account for seismic site conditions. VS30 is typically based on geophysical measurements of VS derived from invasive and noninvasive techniques at sites of interest. Owing to cost considerations, as well as logistical and environmental concerns, VS30 data are sparse or not readily available for most areas. Where data are available, VS30 values are often assembled in assorted formats that are accessible from disparate and (or) impermanent Websites. To help remedy this situation, we compiled VS30 measurements obtained by studies funded by the U.S. Geological Survey (USGS) and other governmental agencies. Thus far, we have compiled VS30 values for 4,369 sites in the United States, along with metadata for each measurement from government-sponsored reports, online databases, and scientific and engineering journals. Most of the data in our VS30 compilation originated from publications directly reporting the work of field investigators. A subset consisting of 20 percent of VS30 values was previously compiled by the USGS and other research institutions. VS30 originating from these earlier compilations were crosschecked against published reports when clarification was needed. Both downhole and surface-based VS30 estimates are represented in our VS30 compilation. Most of the VS30 data are for sites in the western contiguous United States (3,128 sites); 682 VS30 values are for sites in the Central United States; 267 VS30 values are for sites in the Eastern United States and Puerto Rico; 15 VS30 values are for sites in Alaska; 30 VS30 values are for sites in Hawaii. The remaining 247 sites are in the vicinity of Vancouver, Canada.

VS30, the time-averaged shear-wave velocity (VS) to a depth of 30 meters, is a key index adopted by the earthquake engineering community to account for seismic site conditions. VS30 is typically based on geophysical measurements of VS derived from invasive and noninvasive techniques at sites of interest. Owing to cost considerations, as well as logistical and environmental concerns, VS30 data are sparse or not readily available for most areas. Where data are available, VS30 values are often assembled in assorted formats that are accessible from disparate and (or) impermanent Websites. To help remedy this situation, we compiled VS30 measurements obtained by studies funded by the U.S. Geological Survey (USGS) and other governmental agencies. Thus far, we have compiled VS30 values for 4,369 sites in the United States, along with metadata for each measurement from government-sponsored reports, online databases, and scientific and engineering journals. Most of the data in our VS30 compilation originated from publications directly reporting the work of field investigators. A subset consisting of 20 percent of VS30 values was previously compiled by the USGS and other research institutions. VS30 originating from these earlier compilations were crosschecked against published reports when clarification was needed. Both downhole and surface-based VS30 estimates are represented in our VS30 compilation. Most of the VS30 data are for sites in the western contiguous United States (3,128 sites); 682 VS30 values are for sites in the Central United States; 267 VS30 values are for sites in the Eastern United States and Puerto Rico; 15 VS30 values are for sites in Alaska; 30 VS30 values are for sites in Hawaii. The remaining 247 sites are in the vicinity of Vancouver, Canada.

In October 2016 and May 2017 frequency domain electromagnetic (FDEM) methods were used to image the electrical conductivity of the shallow subsurface. Electrical conductivity can be caused by changes in the soil, overburden, saturation, and water quality. Two multi-frequency tools were used at the site. One of the tools has a 1.6-meter (m) long antenna that was used in the vertical-dipole mode to collect data in stepped-frequency mode at seven user-selected frequencies ranging from 1530 to 47,970 Hertz (Hz). The GEM2HG has an antenna that is 2.1 m long, and it was used in vertical dipole mode with five stepped frequencies ranging from 90 to 24,000 Hz. In general, the lower frequencies penetrate to deeper depths, but the data are an average over a larger volume; whereas higher frequencies penetrate only to shallow depths but provide a smaller volume-averaged measurement. Data were collected at walking speeds of 3 kilometers per hour (km/hr), with a full suite of seven frequencies measured every 0.5 seconds (s), which translates to a complete measurement suite about every 0.4 m along the profile. All measurements were georeferenced with a global positioning system (GPS). Both the primary and secondary fields were measured at the receiver coil, and the ratio of the secondary to primary magnetic fields was recorded as in-phase and quadrature. The in-phase part of the EM field relates to the magnetic susceptibility, and the quadrature component relates to apparent conductivity (aEC) . Raw data for each frequency and Q Sum (a summation of quadrature values) were recorded in parts per million (ppm). In post processing, EM data were converted to magnetic susceptibility and aEC, which can be inverted to get the actual depth of the electrical conductivity value. This data release provides the raw ppm values, the magnetic susceptibility, and the apparent electrical conductivity values.

This dataset includes a final report and a 3D velocity model derived from seismic DAS and geophone borehole data collected during the April 2024 stimulation of the reservoir at Utah FORGE. The report details the processing of over 50,000 P- and S-wave travel times used in a tomographic inversion to estimate the Vp/Vs ratio, revealing anomalies adjacent to wells 16A and 16B that may be associated with injected fracturing fluids. Additionally, Wadati analysis of more than 27,000 pairs of differential P- and S-wave travel times supports this interpretation with a high Vp/Vs estimate of 1.86, averaged over the dimensions of the earthquake cluster. The accompanying data file provides a 3D model of P- and S-wave velocities and Vp/Vs ratios, structured with spatial coordinates and velocity values.

In June of 2011, the U.S. Geological Survey acquired high-resolution P- and S-wave seismic data across the mapped (Schussler, 1906) trace of the San Andreas Fault zone at San Andreas Lake in unincorporated San Mateo County, California. Our seismic survey consisted of seismic reflection, refraction, and guided-wave data along a 60-m-long profile. To acquire the reflection and refraction data we co-located shots and geophones, spaced every meter along the profile. We used 59 SercelTM L40A, P-wave (40-Hz vertical-component) geophones (sensitivity of 22.34 volts/meter/second) to record 59 P-wave shots and 59 SercelTM L28-LBH, S-wave (4.5-Hz horizontal-component) geophones (sensitivity of 31.3 volts/meter/second)to record 59 S-wave shots. We generated P-wave data using a charge from a Betsy SeisgunTM, with the charge placed approximately 0.4 meters (16 inches) beneath the ground surface. The charge consisted of an 8-gauge, 400-grain, blank shotgun shell. S-wave sources were generated by horizontally striking an aluminum block with a 3.5-kg sledgehammer. We acquired fault-zone-guided-wave data using approximately one pound of explosives within a mapped trace of the San Andreas Fault, approximately 1.74 km NNW of the recording arrays. The explosives were placed in a 5-cm (2 inch) diameter borehole approximately 3-meter (10 feet) deep. All data were recorded using a 60-channel Geometrics Stratavisor NX-60TM seismograph with a 24-bit analog-to-digital converter and a roll-along descaling factor, and the output data are in SEG-Y format (Barry et al, 1975). Each in-line shot was recorded for two seconds, with data recording starting 100 ms before the actual time of the shot. Data were recorded at a sampling rate of 0.5 ms, or 2000 samples per second. This report provides the metadata needed to analyze the seismic data. References Barry, K.M., Cavers, D.A. and Kneale, C.W., 1975, Recommended standards for digital tape formats: Geophysics, vol. 40, no. 2, p. 344-352. Schussler, H., 1906, The Water Supply of San Francisco, California, Before, During, and After the Earthquake of April 18, 1906 and the Subsequent Conflagration: Martin B. Brown Press, New York, 103 pp.

In June of 2011, the U.S. Geological Survey acquired high-resolution P- and S-wave seismic data across the mapped (Schussler, 1906) trace of the San Andreas Fault zone at San Andreas Lake in unincorporated San Mateo County, California. Our seismic survey consisted of seismic reflection, refraction, and guided-wave data along a 60-m-long profile. To acquire the reflection and refraction data we co-located shots and geophones, spaced every meter along the profile. We used 59 SercelTM L40A, P-wave (40-Hz vertical-component) geophones (sensitivity of 22.34 volts/meter/second) to record 59 P-wave shots and 59 SercelTM L28-LBH, S-wave (4.5-Hz horizontal-component) geophones (sensitivity of 31.3 volts/meter/second)to record 59 S-wave shots. We generated P-wave data using a charge from a Betsy SeisgunTM, with the charge placed approximately 0.4 meters (16 inches) beneath the ground surface. The charge consisted of an 8-gauge, 400-grain, blank shotgun shell. S-wave sources were generated by horizontally striking an aluminum block with a 3.5-kg sledgehammer. We acquired fault-zone-guided-wave data using approximately one pound of explosives within a mapped trace of the San Andreas Fault, approximately 1.74 km NNW of the recording arrays. The explosives were placed in a 5-cm (2 inch) diameter borehole approximately 3-meter (10 feet) deep. All data were recorded using a 60-channel Geometrics Stratavisor NX-60TM seismograph with a 24-bit analog-to-digital converter and a roll-along descaling factor, and the output data are in SEG-Y format (Barry et al, 1975). Each in-line shot was recorded for two seconds, with data recording starting 100 ms before the actual time of the shot. Data were recorded at a sampling rate of 0.5 ms, or 2000 samples per second. This report provides the metadata needed to analyze the seismic data. References Barry, K.M., Cavers, D.A. and Kneale, C.W., 1975, Recommended standards for digital tape formats: Geophysics, vol. 40, no. 2, p. 344-352. Schussler, H., 1906, The Water Supply of San Francisco, California, Before, During, and After the Earthquake of April 18, 1906 and the Subsequent Conflagration: Martin B. Brown Press, New York, 103 pp.