Airborne electromagnetic (AEM) geophysical data were collected in California as a part of AEM pilot studies. The purpose of the AEM pilot studies was to inform the development of the Department of Water Resources’ (DWR’s) statewide AEM survey project. The AEM pilot studies were conducted in three areas: Butte and Glenn Counties, San Luis Obispo County, and Indian Wells Valley. The AEM surveys were conducted from 2018 through 2020 and were led by Stanford University with participants from the academic and private sectors, and local and state water agencies. All data used, collected, or created as a part of the AEM pilot studies are provided here. The AEM pilot studies were funded by grants from DWR, the Ministry of Denmark, and three local agencies (Butte County, Indian Wells Valley Water District, and San Luis Obispo County - Paso Robles). Pilot study participants included Stanford University, Aarhus University, Aqua Geo Frameworks, Ramboll, I-GIS, SkyTEM, University of California Davis, California State University Sacramento, California State University Chico, Parker Groundwater, the Danish Water Technology Alliance, the Danish Environmental Protection Agency, Glenn County Department of Water Resource Conservation, Butte County Department of Water Conservation, Indian Wells Valley Water District, and San Luis Obispo County.

#Statewide AEM Surveys Project Overview The Department of Water Resources’ (DWR’s) Statewide Airborne Electromagnetic (AEM) Surveys Project is funded through California’s Proposition 68 and the General Fund. The goal of the project is to improve the understanding of groundwater aquifer structure to support the state and local goal of sustainable groundwater management and the implementation of the Sustainable Groundwater Management Act (SGMA). During an AEM survey, a helicopter tows electronic equipment that sends signals into the ground which bounce back. The data collected are used to create continuous images showing the distribution of electrical resistivity values of the subsurface materials that can be interpreted for lithologic properties. The resulting information will provide a standardized, statewide dataset that improves the understanding of large-scale aquifer structures and supports the development or refinement of hydrogeologic conceptual models and can help identify areas for recharging groundwater. DWR is collecting AEM data in all of California’s high- and medium-priority groundwater basins, where data collection is feasible. Data are collected in a coarsely spaced grid, with a line spacing of approximately 2-miles by 8-miles. AEM data collection started in 2021 and will continue over the next several years. Visit the AEM Survey Schedule Webpage to get up-to-date information on the survey schedule: https://gis.water.ca.gov/app/AEM-schedule. Additional information about the Statewide AEM Surveys can be found at the project website: https://water.ca.gov/Programs/SGMA/AEM. # Survey Areas AEM data are being collected in groups of groundwater basins, defined as a Survey Area. See Survey Area Map for groundwater subbasins within a Survey Area: https://data.cnra.ca.gov/dataset/aem/resource/a6286b07-5597-49e6-9cac-6a3a98b904df + Survey Area 1: 180/400 Foot Aquifer (partial), East Side (partial), Upper Valley, Forebay Aquifer, Paso Robles, Atascadero (limited), Adelaida (limited), Cuyama Valley. + Survey Area 2: Scott River Valley, Shasta Valley, Butte Valley, Tulelake, Fall River Valley (limited), Big Valley (Modoc/Lassen County). + Survey Area 3: Big Valley (Lake County), Ukiah Valley, Santa Rosa Plain, Petaluma Valley, Sonoma Valley. + Survey Area 4: White Wolf, Kern County, Tulare Lake, Tule, Kaweah. + Survey Area 5: Pleasant Valley, Westside, Kings, Madera, Chowchilla, Merced, Turlock, Modesto, Delta-Mendota + Survey Area 6: Cosumnes, Tracy, Eastern San Joaquin, East Contra Costa, Solano, Livermore, South American, North American, Yolo, Sutter, South Yuba, North Yuba + Survey Area 7: Colusa, Butte, Wyandotte Creek, Vina, Los Molinos, Corning, Red Bluff, Antelope, Bowman, Bend, Millville, South Battle Creek, Anderson, Enterprise, Eel River, Sierra Valley + Survey Area 8: Seaside, Monterey, 180/400 (partially surveyed Summer 2021), Eastside (partially surveyed Summer 2021), Langley, Pajaro, Santa Cruz Mid-County, Santa Margarita, San Benito, and Llagas (partial). + Survey Area 9: Basin Characterization Pilot Study 1 - Madera and Kings. + Survey Area 10: San Antonio Creek Valley, Arroyo Grande, Santa Maria, San Luis Obispo, Los Osos Area, Warden Creek, Chorro Valley (limited), Morro Valley (limited) + Survey Area 11: Indian Wells Valley, Rose Valley, Owens Valley, Fish Slough, Indio, Mission Creek, West Salton Sea (limited), East Salton Sea (limited), Ocotillo-Clark Valley (limited), Imperial Valley (limited),Chocolate Valley (limited), Borrego Springs, and San Jacinto # Data Reports Data reports detail the AEM data collection, processing, inversion, interpretation, and uncertainty analyses methods and procedures. Data reports also describe additional datasets used to support the AEM surveys, including digitized lithology and geophysical logs. Multiple data reports may be provided for a single Survey Area, depending on the Survey Area coverage. # Data Availability and Types All data collected as a part of the

#Statewide AEM Surveys Project Overview The Department of Water Resources’ (DWR’s) Statewide Airborne Electromagnetic (AEM) Surveys Project is funded through California’s Proposition 68 and the General Fund. The goal of the project is to improve the understanding of groundwater aquifer structure to support the state and local goal of sustainable groundwater management and the implementation of the Sustainable Groundwater Management Act (SGMA). During an AEM survey, a helicopter tows electronic equipment that sends signals into the ground which bounce back. The data collected are used to create continuous images showing the distribution of electrical resistivity values of the subsurface materials that can be interpreted for lithologic properties. The resulting information will provide a standardized, statewide dataset that improves the understanding of large-scale aquifer structures and supports the development or refinement of hydrogeologic conceptual models and can help identify areas for recharging groundwater. DWR is collecting AEM data in all of California’s high- and medium-priority groundwater basins, where data collection is feasible. Data are collected in a coarsely spaced grid, with a line spacing of approximately 2-miles by 8-miles. AEM data collection started in 2021 and will continue over the next several years. Visit the AEM Survey Schedule Webpage to get up-to-date information on the survey schedule: https://gis.water.ca.gov/app/AEM-schedule. Additional information about the Statewide AEM Surveys can be found at the project website: https://water.ca.gov/Programs/SGMA/AEM. # Survey Areas AEM data are being collected in groups of groundwater basins, defined as a Survey Area. See Survey Area Map for groundwater subbasins within a Survey Area: https://data.cnra.ca.gov/dataset/aem/resource/a6286b07-5597-49e6-9cac-6a3a98b904df + Survey Area 1: 180/400 Foot Aquifer (partial), East Side (partial), Upper Valley, Forebay Aquifer, Paso Robles, Atascadero (limited), Adelaida (limited), Cuyama Valley. + Survey Area 2: Scott River Valley, Shasta Valley, Butte Valley, Tulelake, Fall River Valley (limited), Big Valley (Modoc/Lassen County). + Survey Area 3: Big Valley (Lake County), Ukiah Valley, Santa Rosa Plain, Petaluma Valley, Sonoma Valley. + Survey Area 4: White Wolf, Kern County, Tulare Lake, Tule, Kaweah. + Survey Area 5: Pleasant Valley, Westside, Kings, Madera, Chowchilla, Merced, Turlock, Modesto, Delta-Mendota + Survey Area 6: Cosumnes, Tracy, Eastern San Joaquin, East Contra Costa, Solano, Livermore, South American, North American, Yolo, Sutter, South Yuba, North Yuba + Survey Area 7: Colusa, Butte, Wyandotte Creek, Vina, Los Molinos, Corning, Red Bluff, Antelope, Bowman, Bend, Millville, South Battle Creek, Anderson, Enterprise, Eel River, Sierra Valley + Survey Area 8: Seaside, Monterey, 180/400 (partially surveyed Summer 2021), Eastside (partially surveyed Summer 2021), Langley, Pajaro, Santa Cruz Mid-County, Santa Margarita, San Benito, and Llagas (partial). + Survey Area 9: Basin Characterization Pilot Study 1 - Madera and Kings. + Survey Area 10: San Antonio Creek Valley, Arroyo Grande, Santa Maria, San Luis Obispo, Los Osos Area, Warden Creek, Chorro Valley (limited), Morro Valley (limited) + Survey Area 11: Indian Wells Valley, Rose Valley, Owens Valley, Fish Slough, Indio, Mission Creek, West Salton Sea (limited), East Salton Sea (limited), Ocotillo-Clark Valley (limited), Imperial Valley (limited),Chocolate Valley (limited), Borrego Springs, and San Jacinto # Data Reports Data reports detail the AEM data collection, processing, inversion, interpretation, and uncertainty analyses methods and procedures. Data reports also describe additional datasets used to support the AEM surveys, including digitized lithology and geophysical logs. Multiple data reports may be provided for a single Survey Area, depending on the Survey Area coverage. # Data Availability and Types All data collected as a part of the

This animation shows how Airborne Electromagnetic Surveys Work. It is part of a series of Field Activity Technique Engagement Animations. The target audience are the communities that are impacted by our data acquisition activities. There is no sound or voice over. The 2D animations include a simplified view of what AEM equipment looks like, what the equipment measures and how the survey works.

This animation shows how Airborne Electromagnetic Surveys Work. It is part of a series of Field Activity Technique Engagement Animations. The target audience are the communities that are impacted by our data acquisition activities. There is no sound or voice over. The 2D animations include a simplified view of what AEM equipment looks like, what the equipment measures and how the survey works.

This animation shows how Airborne Electromagnetic Surveys Work. It is part of a series of Field Activity Technique Engagement Animations. The target audience are the communities that are impacted by our data acquisition activities. There is no sound or voice over. The 2D animations include a simplified view of what AEM equipment looks like, what the equipment measures and how the survey works.

In recent years, Geoscience Australia, along with the state and territory geological surveys, have collected and processed vast amounts of airborne electromagnetic (AEM) data. With the acquisition of the AusAEM survey (Ley-Cooper et al., 2020) and the intention to collect large amounts of interpretation-specific metadata for the Estimates of Geological and Geophysical Surfaces database (EGGS; Mathews et al., 2020), an assessment was made on the available software capable of efficiently creating the intended interpretations. Shortcomings in existing applications prompted the development of a new interpretation workflow: the Multilayered chronostratigraphic airborne electromagnetic interpretation workflow (Wong et al., 2022). This workflow facilitates digitising the interpretation linework and attributing these lines with a wide range of interpretation-specific data. Development of this workflow prioritised accessibility by utilising widely-used Geographic Information Systems and open-source software. The conversion component can provide the interpretation outputs in a range of formats compatible with most applicable software packages. This conversion process also includes the production of interpretation aids prior to interpretation and to validate spatial, geometric and attribute data, post interpretation. The conversion component in this workflow was initially scripted in the AWK programming language, which is currently used in Geoscience Australia’s production Multilayered chronostratigraphic AEM interpretation workflow (Wong et al., 2022). This conversion process has been used to convert AEM interpretation from over 115,000 flight line km, covering mostly 20 km-spaced flight lines over an area of 2,085,000 km2 or 27% of the Australian continent (Connors et al., 2022; Folkes et al., 2022; Vilhena et al. 2023; Wong et al., 2020; Wong et al., 2021; Wong et al., 2023). The AEMInterpConvert tool has been developed to improve accessibility and user-friendliness of the interpretation conversion component of the workflow. This tool allows users to produce the interpretation aids, run the validations and export interpretation in various formats without the need for any specialised software or programming experience. This document provides a metadata statement and user guide for the AEMInterpConvert’s online graphical user interface. Outputs from this tool are designed to support investigations of cover thicknesses and depths to basements for 3D geological modelling. These interpretations and models are in turn used to inform academia, industry and government on decision-making, land use, environmental management, hazard mapping and resource exploration.

This service provides access to airborne electromagnetics (AEM) derived conductivity grids in the Upper Darling Floodplain region. The grids represent 30 depth intervals from modelling of AEM data acquired in the Upper Darling Floodplain, New South Wales, Airborne Electromagnetic Survey (https://dx.doi.org/10.26186/147267), an Exploring for the Future (EFTF) project jointly funded by Geoscience Australia and New South Wales Department of Planning and Environment (NSW DPE). The AEM conductivity model delineates important subsurface features for assessing the groundwater system including lithological boundaries, palaeovalleys and hydrostatigraphy.

This service delivers airborne electromagnetics (AEM) derived conductivity grids for depth intervals representing the top 22 layers from AEM modelling in the West Musgrave region (https://dx.doi.org/10.26186/147969). The grids were generated from the AEM conductivity models released as part of the Western Resource Corridor AusAEM survey (https://dx.doi.org/10.26186/147688), the Earaheedy and Desert Strip AusAEM survey (https://pid.geoscience.gov.au/dataset/ga/145265) and several industry surveys (https://dx.doi.org/10.26186/146278) from the West Musgraves region. The AEM conductivity models resolve important subsurface features for assessing the groundwater system including lithological boundaries, palaeovalleys and hydrostatigraphy.

Airborne electromagnetic (AEM) and magnetic survey data were collected during March 2022 over a distance of 2,574.6 line kilometers in southeast and southwest Wisconsin. These data were collected in support of an effort to improve estimates of depth to bedrock through a collaborative project between the U.S. Geological Survey (USGS), Wisconsin Department of Agriculture, Trade, and Consumer Protection (DATCP), and Wisconsin Geological and Natural History Survey (WGNHS). Data were acquired by SkyTEM Canada Inc. with the SkyTEM 304M time-domain helicopter-borne electromagnetic system together with a Geometrics G822A cesium vapor magnetometer. The survey was acquired at a nominal flight height of 30 - 40 meters (m) above terrain. AEM data were inverted to produce models of electrical resistivity along flight paths, with typical depth of investigation up to about 400 m and 1 - 2 m near-surface resolution.