Katie M. Hulsey Burke J. Minsley Jade W. Crosbie Ryan F. Adams Carole D. Johnson Eric A. White Emilia L. Bristow Amy M. Gahala 20250923 tabular digital data https://doi.org/10.5066/P13WHWZR Horizontal-to-Vertical Spectral Ratio (HVSR) passive seismic soundings were collected by the U.S. Geological Survey (USGS) at 27 locations throughout the Illinois River Basin (IRB) in October and November 2022. The USGS collected these data to characterize depth to bedrock in support of the USGS Next Generation Water Observing System (NGWOS) IRB program and for comparison to Airborne Electromagnetic and magnetic survey data. Data were collected by two teams, each equipped with either two Tromino Blu seismometers (https://moho.world/en/tromino/) or one Tromino Blu seismometer and one SmartSolo IGU-16HR seismometer (https://smartsolo.com/). Two soundings were collected simultaneously at each measurement point by instruments positioned near each other. Tromino data were processed using MOHO Grilla HVSR software (https://moho.world/en/moho/), and SmartSolo data were processed using Python functions. Data were collected to characterize depth to bedrock in support of the USGS NGWOS IRB program and for comparison to Airborne Electromagnetic and magnetic survey data. HVSR data are compressed to .zip files for each instrument and data type. "NGWOS_IRB_HVSR_index.csv" is a comma-separated values (csv) file with an index of all the HVSR measurements included here and includes data on acquisition and processing for each measurement. "Tromino_raw_files.zip" contains raw seismic data from Tromino seismometers in .trc and .saf files. .Trc files are binary files recorded by a Tromino device and imported into Grilla software and .saf files are ascii files exported from Grilla. "Tromino_processed.zip" contains .jpg files with plots of single component spectra and horizontal to vertical spectral ratio for each measurement from Tromino seismometers. "SmartSolo_raw_files.zip" contains raw data recorded by the SmartSolo seismometer, in .miniseed and .saf format. .miniseed is the file format for seismic data recorded using the SmartSolo seismometer. Each recording is saved in three separate .miniseed files, one for each directional component (E,N, or Z). The directional component is noted in the filename. The .saf files are ascii files with raw data exported from seismic processing software. In .saf files, the three directional components are combined into one file for each recording. "SmartSolo_processed.zip" contains .jpg files with plots of single component spectra and horizontal to vertical spectral ratio for each SmartSolo measurement. DEM for “Point_DEM_Elev” is the elevation value in meters (North American Vertical Datum 1988). This value is from a Digital Elevation Model (DEM) for the interpretation of NGWOS IRB geophysical data at a regional scale appropriate for the NGWOS IRB Airborne Electromagnetic survey data. The DEM is re-sampled at resolution of 500 meter cell size from the higher-resolution 10 meter cell size of the Illinois StreamStats DEM (Schafer and Sharpe, 2023), which can be accessed at https://doi.org/10.5066/P9YIAUZQ. 20221031 20221104 ground condition Complete None planned -91.0000 -87.5000 42.5000 39.0000 ISO 19115 Topic Category geoscientificInformation None Geophysics Aquifer characterization HVSR Horizontal-to-vertical spectral ratio Passive seismic Tromino SmartSolo NGWOS USGS Metadata Identifier USGS:66840f0bd34e0f592272b400 None Illinois Illinois River basin None. Please see 'Distribution Info' for details. None. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations. Katie (KT) M. Hulsey U.S. Geological Survey, Central Midwest Water Science Center Hydrologist mailing address

401 NW Capital Drive

Lees Summit MO 64086 US 816-554-3489 217-328-9770 khulsey@usgs.gov Data includes raw instrument files, with these data being processed to varied degrees, depending on the specific objectives of the work. Data were reviewed for consistency. Data set is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details. Data collection: HVSR data were collected by two field teams in conjunction with TEM surveys on 10/31/2022 - 11/04/2022. Each team had two seismometers: one team had a Tromino Blu with serial number TEB-0485/01-19 (labelled as 485 in this data release) and a Tromino Blu with serial number TEB-0618/01-21 (labelled as 618 in this data release), and the other team had one Tromino Blu with serial number TEB-0486/01-19 (labelled 486 in this data release) and one SmartSolo IGU-16HR seismic sensor with serial number 453020959. Two seismometers were positioned adjacent to each other at each measurement point and measurements were collected simultaneously to allow for redundant data for quality assurance. Seismometers were coupled to the ground using ground spikes or gravitometer plate based on local ground conditions. Measurement point location was collected using an Eos Positioning Systems GPS system. Seismic data was recorded for between 12 and 195 minutes at each site depending on local conditions and at the discretion of the field team at the site. 2022 Data processing Data collected on Tromino seismometers were processed using MOHO Grilla software version 9.6.3 (https://moho.world/en/moho/), a commercially available program. Data collected using the SmartSolo seismometer were processed using Python signal processing functions from the SciPy (version 1.9.0, https://scipy.org/) and ObsPy (version 1.3.0, https://github.com/obspy/obspy) libraries. Both processing routines filtered and processed the data to determine the resonance frequency. Data processing included the use of band-pass filtering to remove instrument drift, data spikes, and other high-frequency noise, and a post-processing spectral smoothing. Both programs computed the average amplitude spectra of the two horizontal components and the vertical component for user specified time-windows, and then calculated the ratio of the horizontal and vertical amplitude spectra. The plotted spectral ratios were examined to determine resonance peak. 2022 Albers Conical Equal Area 29.5 45.5 -96.0 23.0 0.0 0.0 coordinate pair 0.001 0.001 meters North American Datum of 1983 (NAD 83) Geodetic Reference System 1980 6378137.000000 298.257222 North American Vertical Datum of 1988 0.01 meters Attribute values NGWOS_IRB_HVSR_index.csv Comma Separated Values (CSV) file containing information about the HVSR points. Producer Defined Filename Unique filename text string for each measurement Producer Defined The filename string for Tromino data files is a concatenation of site number, site name, instrument ID, and point ID. The filename for SmartSolo files is a concatenation of site number and site name. Site number Number (string) identifying geophysical survey sites. Producer Defined 1 34 Site name Text string with name of geophysical survey site Producer Defined Site names are generally taken from the name of the park or facility where the survey took place. PointID Number assigned to each measurement point. In some cases more than one measurement point exists within a given site. Producer Defined 2 73 Instrument Identifying code of the instrument that took each measurement. Producer Defined Tromino-486 Tromino Blu seismometer with serial number TEB-0486/01-19 Producer defined Tomino - 618 Tromino Blu seismometer with serial number TEB-0618/01-21 Producer defined Tomino - 485 Tromino Blu seismometer with serial number TEB-0485/01-19 Producer defined SmartSolo SmartSolo IGU-16HR seismometer with serial number 453020959 Producer defined Date Collected Date on which the measurement was collected Producer Defined 10/31/22 11/04/22 Recording length minutes Length of data recording (in minutes) Producer Defined 12.4 195.1978 File start time Measurement start time recorded by instrument - Tromino measurements only. Note: This is not the actual start time of the measurement, but the start time using the Tromino's internal clock, which was not set accurately. Format: hh:mm:ss Producer Defined 5:52:18 22:47:35 Point_X_Albers5070 Point easting in Conus Albers NAD83 Producer Defined 429765.1064 675093.0073 meter Point_Y_Albers5070 Point northing in Conus Albers NAD83 Producer Defined 1781658.2619 2190501.5594 meters Point_DEM_Elev Elevation in meters above mean sea level, determined from 3m DEM. See "Supplemental Information" for more information on DEM. Producer Defined 128.385 272.055 meters Peak Freq 1 (Hz) Peak fundamental resonance frequency in Hertz as noted on spectral ratio plot. Producer Defined 0.84 70.22 Hertz Peak Freq 1 (Hz)_+/- Uncertainty (Hz) Peak frequency uncertainty in Hertz as noted on spectral ratio plot. Producer Defined 0.01 28.29 Hertz Coupling Type Method for coupling seismometer with ground Producer Defined Ground Seismometer was coupled to ground using ground spikes. Producer defined Plate Seismometer was coupled to ground using a gravitometer plate. Producer defined Peak Freq 1 Quality Rank 1-5, 1-best Data quality assessment ranging from 1 (best) to 5 (worst) Producer Defined 1 5 Smoothing type Smoothing setting used in data processing Producer Defined triangle data smoothed using the triangle window function Producer defined Smooth perc Smoothing percentage setting used in Grilla smoothing options. This is applicable only for the Tromino data processed in Grilla, not SmartSolo data. Producer Defined 10 15 Window_size Smoothing window sizes used in smoothing settings Producer Defined 15 90 Hz_start Minimum frequency setting in Hertz for peak frequency analysis Producer Defined 0.0 4.0 Hertz Hz_end Maximum frequency setting in Hertz for peak frequency analysis Producer Defined 2.0 128.0 Hertz Notes Text string with data processing notes Producer Defined Text string with data processing notes Tromino_raw_files.zip Zipped folder containing raw data files from Tromino seismometer. The '.trc' files are binary files containing raw seismic data collected by a Tromino device. The '.saf' files contain raw seismic data exported for each measurement from the original '.trc' format. Producer Defined filename_EqualizedFile.saf The '.saf' file is an ASCII file with raw seismic data exported from the original format. The "filename" is as in the "NGWOS_IRB_HVSR_index.csv" file. Producer defined Raw data from each survey in ASCII format filename_EqualizedFile.trc The '.trc' file is a binary file with raw seismic data. The "filename" is as in the "NGWOS_IRB_HVSR_index.csv" file. Producer defined Raw data from each survey in a binary file. Tromino_processed_files.zip Zipped folder containing image files showing processed data from Tromino seismometer. Producer Defined filename_HVSR.jpg Image file showing the plotted H/V curve and identified max H/V. The "filename" is as in the "NGWOS_IRB_HVSR_index.csv" file. Producer defined Image files showing plots of HVSR data filename_PowSpecTot.jpg Image file showing the plotted N-S, E-W, and Up-Down component power spectra. The "filename" is as in the "NGWOS_IRB_HVSR_index.csv" file. Producer defined Image files showing plots of HVSR data SmartSolo_raw_files.zip Zipped folder containing raw data files from SmartSolo seismometer. Producer Defined filename_RawData.component.miniseed The '.miniseed' file is a file containing raw seismic data collected by a SmartSolo device. The "filename" is as in the "NGWOS_IRB_HVSR_index.csv" file. Each recording has three miniseed files, one for each directional component: E, N, or Z. Producer defined Raw seismic data collected by a SmartSolo device. filename.saf The '.saf' file is an ASCII file with raw seismic data exported from the original format. The "filename" is as in the "NGWOS_IRB_HVSR_index.csv" file. Producer defined Raw data from each survey in ASCII format SmartSolo_processed_files.zip Zipped folder containing image files showing processed data from SmartSolo seismometer. Producer Defined filename.jpg Image file showing the plotted H/V curve, in red, with upper and lower error bounds in black, and identified max H/V. The "filename" is as in the "NGWOS_IRB_HVSR_index.csv" file. Producer defined Image files showing plotted HVSR data Augen_filename.jpg Image file showing the plotted N-S, E-W, and Up-Down component power spectra. The "filename" is as in the "NGWOS_IRB_HVSR_index.csv" file. Producer defined Image files showing plotted HVSR data U.S. Geological Survey GS ScienceBase mailing address

Denver Federal Center, Building 810, Mail Stop 302

Denver CO 80225 United States 1-888-275-8747 sciencebase@usgs.gov Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Digital Data https://doi.org/10.5066/P13WHWZR None 20250923 Emilia L Bristow U.S. Geological Survey, Central Midwest Water Science Center Hydrologist mailing and physical

400 S Clinton St, Federal Building

Iowa City IA 52240 US 319-358-3609 ebristow@usgs.gov FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998