Benjamin R. Bloss Lyndsay B. Ball Krishangi D. Groover 20220810 CSV, TEM, USF, PDF Denver, CO U.S. Geological Survey Additional information about Originator: Bloss, B.R., https://orcid.org/0000-0002-1678-8571; Ball, L.B., https://orcid.org/0000-0002-6356-4693; Groover, K.D., http://orcid.org/0000-0002-5805-8913; https://doi.org/10.5066/P908GEV7 Ground-based transient electromagnetic (TEM) data were acquired by the U.S. Geological Survey (USGS) at 16 locations of California’s southwestern San Joaquin Valley and Central Coast regions to define the electrical resistivity structure of hydrogeologic materials. Data were acquired using the ABEM WalkTEM system (Guideline Geo Ab, Sundbyberg, Sweden). TEM data were processed and numerically inverted to derive the one-dimensional resistivity structure at each site using SPIA (Aarhus Geosoftware, Aarhus, Denmark). The resulting models reveal vertical variations in electrical resistivity associated with geologic properties and groundwater salinity. This release includes raw and processed TEM data and a resistivity model for each data location. These data were collected in support of groundwater salinity mapping and hydrogeologic framework development as part of the California State Water Resources Control Boards Oil and Gas Regional Monitoring Program and the U.S. Geological Survey California Oil, Gas, and Groundwater Program. Data file Types: - *.usf files - these contain the raw TEM data. Format described in USF_format_description_508.pdf; - *.tem files - these contain processed TEM data. Format described in AarhusInv_manual_TEM.txt; - Model file is in CSV format and contains electrical resistivity models produced using ground-based TEM data. The naming convention is a combination of the project (COGG), data type (TEM), acquisition date (YYMMDD), survey name (CC:Cat Canyon, EH:Elk Hills, LH:Lost Hills, SA:San Ardo), and site number ID (01c, 04a, etc...); - Model data dictionary is in CSV format and contains a definition and units for all columns in model file. Data Files: COGG_TEM_data_models_2019.zip ├── Data │ ├── COGG_Raw_Data (USF Files) │ │ ├── USF_format_description_508.pdf - manual describing the USF file format │ │ ├── COGG_SoundingID-USF_lookup.csv - lookup table linking USF file to Sounding ID. Also includes information on WalkTEM channel mapping for moment and receiver types │ │ └── USF files (16 files) - raw, unprocessed data files with naming convention [LONGDATE] + [_TIMESTAMP] + [_STATIONID].usf, where LONGDATE (ex.20160621), TIMESTAMP (ex. 230145_828), STATIONID (ex. Station1) │ └── COGG_Processed_Data (TEM Files) │ ├── AarhusInv_manual_TEM.txt - manual describing the TEM file format │ └── TEM files (64 files) - processed data files with naming convention [COGG_TEM] + [_DATE] + [_SURVEY_NAME] + [_STATION] + [_MOMENT] + [-RECEIVER].tem, where DATE (ex. 180224), Survey (ex. LH), STATION (ex. 01a), MOMENT (ex. LM), RECEIVER (ex. RC005) ├── Models │ ├── COGG_Model_Plots │ │ └── Image files of model plots (16 files) - Images of model plots with naming convention [COGG_TEM] + [_DATE] + [_SURVEY] + [_STATION].png, where DATE (ex. 180224), SURVEY (ex. LH), STATION (ex. 01a) │ ├── TEM_model_data_dictionary.csv - Data dictionary describing all channels in tabulated model file │ └── COGG_TEM_models.csv - tabulated model file. All channels are described in the model data dictionary └── COGG_TEM_2019_Locations.gdb.zip - file-geodatabase containing all sounding locations, model information, and has the model plots linked to each site. The TEM_model_data_dictionary.csv file also applies to the attribute table of this file geodatabase References: Aarhus GeoSoftware Wiki USF_format_Description. (n.d.). Retrieved August 23, 2018, from http://www.ags-cloud.dk/Wiki/S_ImportUSF AarhusInv_manual. (n.d.). Retrieved July 5, 2017, from http://www.hgg.geo.au.dk/HGGsoftware/em1dinv/em1dinv_manual.pdf U.S. Geological Survey, The National Map, 2019, 3DEP products and services: The National Map, 3D Elevation Program Web page, accessed December 5, 2020 at https://nationalmap.gov/3DEP/3dep_prodserv.html Christiansen, A.V. and Auken, E., 2012, A global measure for depth of investigation. GEOPHYSICS, 77(4), WB171-WB177. https://doi.org/10.1190/geo2011-0393.1 20190530 20190605 ground condition Complete as needed -120.9212585 -119.509926 36.02628409 34.81630431 USGS Thesaurus geophysics resistivity GPS measurement electromagnetic surveying hydrogeology geospatial datasets groundwater None U.S. Geological Survey USGS Geology, Geophysics, and Geochemistry Science Center GGGSC California Water Science Center CAWSC California Oil, Gas, and Groundwater COGG SEG dictionary Electromagnetic sounding TEM time-domain electromagnetic method transient electromagnetic method TDEM ISO 19115 Topic Category geoscientificInformation USGS Metadata Identifier USGS:5e18a32ee4b0ecf25c5a3961 USGS Geographic Names Information System (GNIS) Kern County Santa Barbara County Monterey County San Joaquin Valley Cat Canyon Oil Field San Ardo Oil Field Lost Hills Oil Field Elk Hills Oil Field common geographic areas California Central Coast None. Please see 'Distribution Info' for details. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although these data have been processed successfully on a computer system at 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. The USGS or the U.S. Government shall not be held liable for improper or incorrect use of the data described and/or contained herein. Lyndsay B. Ball Geology, Geophysics, and Geochemistry Science Center Research Geophysicist Mailing and Physical

Mail Stop 973, W 6th Ave Kipling St

Lakewood CO 80225 United States 303-236-0133 lbball@usgs.gov ESRI Arcmap v. 10.8.1; SPIA v. 3.3.1.0. This data and model set was produced using the ground based TEM software SPIA (version 3.3.1.0, Aarhus Geosoftware, Aarhus Denmark). which imports and processes raw data and inverts the processed data to create a 1D resistivity model of the subsurface. Attribute fields and values were reviewed and checked for accuracy and consistency of terms. No formal logical accuracy tests were conducted 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. Spatial locations were determined from hand-held global positioning system (GPS) devices. The GPS unit used by field scientists recorded sample locations to within 5 meters of the true location. The locations were verified using a geographic information system (GIS) and digital topographic maps No formal positional accuracy tests were conducted. Ground surface elevations were sampled from the USGS National Map 3D Elevation Program dataset (U.S. Geological Survey, 2019). The vertical accuracy of this dataset is 3 meters. Receiver locations were recorded using a hand-held global positioning system (GPS) device. Ground surface elevations were sampled from the USGS National Map 3D Elevation Program dataset. These locations are presented in the model file "COGG_TEM_models.csv". 2019 Raw data were collected using an ABEM WalkTEM (Guideline Geo Ab, Sundbyberg Sweden). All transmitter loops were 40x40 m. At each location, a series of measurements were taken using two centrally located in-loop receivers with effective areas of 5 m*m (RC005) and 200 m*m (RC200), respectively. Additionally, two transmitter moments were used: 1) low moment (LM) - 1 turn; ~1 Ampere current, 2) high moment (HM) - 1 turn; ~7 Ampere current. Typically, a sounding consisted of six measurements: four transmitter moment-receiver pairs (LM-RC005, LM-RC200, HM-RC005, and HM-RC200) and two noise measurements (No-RC005 and No-RC200) are recorded during a period with no transmissions. Raw data are presented in universal sounding format (*.USF). These files include all recorded sweeps, or transients, for all six measurements. The supplied document "USF_format_description_508.pdf" describes the USF file format. USF filenames are as exported from the WalkTEM and reflect the date, time, and station for that sounding. A lookup table is presented (COGG_SoundingID-USF_lookup.csv) to link USF files to sounding names used in this survey and also provides information about system configuration. Coordinates presented in these files are automatically recorded by the WalkTEM using an internal GPS receiver. These coordinates may be inaccurate as the WalkTEM instrument used during the survey had GPS issues. The coordinates found in both the model file and the file geodatabase are correct and should be used. 2019 Data processing took place within the SPIA TEM processing environment (version 3.3.1.0, Aarhus GeoSoftware, Aarhus Denmark). Data processing entails importing raw transients, assuming 5 percent error on all time gates, rejection of raw transients that show signs of noise and/or contamination, rejection of time gates that fall below the noise floor and show signs of noise and/or contamination, and averaging the remaining data with error analysis to produce a single sounding curve for every transmitter moment-receiver pair. Processed data are presented in TEM format (*.TEM) and the filenames are a concatenation of the sounding location ID, the transmitter moment, and the receiver used. These files include information about the transmitter loop geometry, transmitter waveforms used, filter parameters applied to the data, and present the averaged data and the calculated error. Data rows that are prepended by a "%" are averaged data that have been excluded and were not used in the inversion. The supplied document "AarhusInv_manual_TEM.txt" describes the TEM file format and is extracted from the full manual found at http://www.hgg.geo.au.dk/HGGsoftware/em1dinv/em1dinv_manual.pdf. Coordinates presented in the processed data files were collected with the handheld GPS device at the center of the transmitter and receiver loops and are considered accurate. 2019 Processed data were inverted in the SPIA TEM processing environment (version 3.3.1.0, Aarhus GeoSoftware, Aarhus Denmark). For every sounding location data from all transmitter-receiver pairs were inverted together to create a single model. Careful analysis of model domain was performed to ensure that the model space was sufficient to fit the inverted data. Final depth range for all models begin at the surface and extend to 400 m depth. Presented models used a 50 ohm-meter starting resistivity and a 20 layer, "blocky" style inversion, in which the inversion kernel applies an L1 norm on the vertical resistivity derivative. This pushes the layers to the fewest number of gradients within the model space, regardless of the gradient across any given layer interface. Layer thicknesses were fixed and logarithmically increase with depth. The inversion calculates an estimate of sensitivity to the data with depth. This sensitivity is represented by the two depth-of-investigation (DOI) channels. DOI_Conservative values represent the bottom of the model with a high sensitivity to the data. DOI_Standard values represent the bottom of the model where sensitivity to the data is assumed to be adequate (Christiansen and Auken, 2012, https://doi.org/10.1190/geo2011-0393.1). Inverted resistivity models have been tabulated and are presented in CSV format. The file with the tabulated model parameters is "COGG_TEM_models.csv". Please see the "TEM_model_data_dictionary.csv" file for column definitions, units, and null values. Additionally, sounding plots of both the data- and model-space for every sounding location are presented for ease of use. Coordinates presented in the inverted model files were collected with the handheld GPS device at the center of the transmitter and receiver loops and are considered accurate. 2020 A spatial file geodatabase was created using the "COGG_TEM_models.csv" file and includes the sounding plots as attachments to each point. All attributes found in this file geodatabase are identical to the models csv file and the data dictionary applies here too. 2020 Point Point 16 0.00005 0.00005 Decimal degrees WGS_1984 WGS_84 6378137.0 298.257223563 North American Vertical Datum of 1988 1.0 meter Explicit elevation coordinate included with horizontal coordinates COGG_TEM_2019_Locations.gdb.zip This compressed file geodatabase was generated for ease of use and viewing of model plots. The attribute table of this file is a mirror of the released model file COGG_TEM_models.csv. The model data dictionary (TEM_model_data_dictionary.csv) also applies to this file and defines all attributes data units. Additionally, the Model plots have been attached to each point. Producer defined COGG_SoundingID-USF_lookup.csv Comma Separated Value (CSV) file containing data. Producer Defined SoundingID_TEMFileName Assigned site name for sounding location. Naming convention: [COGG_TEM] + [_DATE] + [_SURVEY] + [_STATION], where DATE (ex. 180224), SURVEY (ex. LH), STATION (ex. 01a) Producer Defined COGG_TEM_180224_LH_01a USF_FileName Filename as generated by the Abem WalkTEM. Name consists of a 4 digit year, 2 digit month, 2 digit day, "_", 2 digit hour, 2 digit minute, 2 digit second, "_", 3 digit microsecond, "_", the station number recorded by the WalkTEM, ".usf". Producer Defined 20190603_132912_968_Station1.usf Channel1 Information linking the recorded software channel to a moment receiver pair. This is based on 1) The acquisition script used and 2) how the WalkTEM was deployed in the field. Producer Defined "LM-RC005" for low-moment, 5 m*m receiver; "LM-RC200" for low-moment, 200 m*m receiver; "HM-RC005" for high-moment, 5 m*m receiver; "HM-RC200" for high-moment, 200 m*m receiver; "No-RC005" for noise, 5m*m receiver; "No-RC200" for noise, 200 m*m receiver Channel2 Information linking the recorded software channel to a moment receiver pair. This is based on 1) The acquisition script used and 2) how the WalkTEM was deployed in the field. Producer Defined "LM-RC005" for low-moment, 5 m*m receiver; "LM-RC200" for low-moment, 200 m*m receiver; "HM-RC005" for high-moment, 5 m*m receiver; "HM-RC200" for high-moment, 200 m*m receiver; "No-RC005" for noise, 5m*m receiver; "No-RC200" for noise, 200 m*m receiver Channel3 Information linking the recorded software channel to a moment receiver pair. This is based on 1) The acquisition script used and 2) how the WalkTEM was deployed in the field. Producer Defined "LM-RC005" for low-moment, 5 m*m receiver; "LM-RC200" for low-moment, 200 m*m receiver; "HM-RC005" for high-moment, 5 m*m receiver; "HM-RC200" for high-moment, 200 m*m receiver; "No-RC005" for noise, 5m*m receiver; "No-RC200" for noise, 200 m*m receiver Channel4 Information linking the recorded software channel to a moment receiver pair. This is based on 1) The acquisition script used and 2) how the WalkTEM was deployed in the field. Producer Defined "LM-RC005" for low-moment, 5 m*m receiver; "LM-RC200" for low-moment, 200 m*m receiver; "HM-RC005" for high-moment, 5 m*m receiver; "HM-RC200" for high-moment, 200 m*m receiver; "No-RC005" for noise, 5m*m receiver; "No-RC200" for noise, 200 m*m receiver Channel6 Information linking the recorded software channel to a moment receiver pair. This is based on 1) The acquisition script used and 2) how the WalkTEM was deployed in the field. Producer Defined "LM-RC005" for low-moment, 5 m*m receiver; "LM-RC200" for low-moment, 200 m*m receiver; "HM-RC005" for high-moment, 5 m*m receiver; "HM-RC200" for high-moment, 200 m*m receiver; "No-RC005" for noise, 5m*m receiver; "No-RC200" for noise, 200 m*m receiver Channel8 Information linking the recorded software channel to a moment receiver pair. This is based on 1) The acquisition script used and 2) how the WalkTEM was deployed in the field. Producer Defined "LM-RC005" for low-moment, 5 m*m receiver; "LM-RC200" for low-moment, 200 m*m receiver; "HM-RC005" for high-moment, 5 m*m receiver; "HM-RC200" for high-moment, 200 m*m receiver; "No-RC005" for noise, 5m*m receiver; "No-RC200" for noise, 200 m*m receiver There are two general types of data in this data release: Data and Models. Within the Data type we present both raw and processed data. For a detailed outline of the directory structure please see the "Supplemental Information" section within this metadata record. DATA RAW_DATA - *.usf - These files contain the raw TEM data. - USF_format_description_508.pdf - This file describes the Universal Sounding Format (USF) file format for the *.usf files. - COGG_SoundingID-USF_lookup.csv - This file contains mapping between the raw data file name (as output by the WalkTEM) and the assigned site name. Additionally, this file provides mapping between USF-channel and transmitter-receiver type (HM_RC200, HM_RC005, LM_RC200, LM_RC005, No_RC200, No_RC005). Raw data file names consist of a date and time stamp as well as station location. Processed data file names follows the following convention of the project (COGG), data type (TEM), acquisition date (YYMMDD), survey name (LH:Lost Hills, EH:Elk Hills, CC: Cat Canyon, SA: San Ardo), and site number ID (01c, 04a, etc...). PROCESSED_DATA - *.tem files - these contain processed TEM data. Naming convention for these files is a combination of the project (COGG), data type (TEM), acquisition date (YYMMDD), survey name (LH:Lost Hills, EH:Elk Hills, CC: Cat Canyon, SA: San Ardo), site number ID (01c, 04a, etc...), transmitter moment (HM, LM), and receiver type (RC200, RC005). - AarhusInv_manual_TEM.txt - File describing the *.tem file format. MODEL - Model file is in CSV format and contains electrical resistivity models produced using ground-based TEM data. The naming convention for each site is a combination of the project (COGG), data type (TEM), acquisition date (YYMMDD), survey name (LH:Lost Hills, EH:Elk Hills, CC: Cat Canyon, SA: San Ardo), and site number ID (01c, 04a, etc...). - TEM_model_data_dictionary.csv - This file defines each column in the model data file and provides the appropriate units. COGG_TEM_2019_Locations.gdb.zip - This compressed file geodatabase was generated for ease of use and viewing of model plots. The attribute table of this file is a mirror of the released model file COGG_TEM_models.csv. The model data dictionary (TEM_model_data_dictionary.csv) also applies to this file and defines all attributes data units. Additionally, the model plots have been attached to each point. Plots include two panels. Model Space: inverted resistivity models (Model Space) with depth of investigation (DOI) estimates. Data Space: measured electromagnetic data with estimated error (AveData_ErrorBar) and forward model responses (FwResp) for each receiver coil (RC005, RC200) and transmitter moment (HM, LM). Bloss, B.R., Ball, L.B., Groover, K.D., 2021, Ground-based transient electromagnetic data and resistivity models at selected sites of the California Central Coast and San Joaquin Valley 2019: U.S. Geological Survey data release, https://doi.org/10.5066/P908GEV7 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. ZIP Complete dataset package of this release as a compressed (Zipped) folder Use a file extraction software such as WinZip, 7zip, Peazip 7.08 https://www.sciencebase.gov/catalog/file/get/5e18a32ee4b0ecf25c5a3961?name=COGG_TEM_data_models_2019.zip No fees are associated with this data release 20220810 Lyndsay B Ball U.S. Geological Survey, ROCKY MOUNTAIN REGION Research Geophysicist mailing address

Mail Stop MS973, W 6th Ave Kipling St

Lakewood CO 80225 US 303-236-0133 303-236-1425 lbball@usgs.gov Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998