U.S. Geological Survey Geoelectromagnetic Monitoring, Surveying, Modeling, and Analysis for Scientific Investigation and Hazard Estimation and Mapping

We summarize updates to data and services provided by the U.S. Geological Survey (USGS) Geomagnetism Program, as well as recent related targeted research results and collaborative projects. Currently, the USGS Geomagnetism Program measures ground-level magnetic field variation continuously at over a dozen magnetic observatories, disseminating these geomagnetic data in near real time to governmental agencies, academic institutions, and the public for purposes of space weather monitoring and geomagnetic field mapping. Since 2022, the President's budget has supported updates to, and a modest expansion of, geomagnetic field monitoring operations. New observatory-grade 3-axis vector magnetometers are replacing legacy sensors at all observatory sites, while modern industrial data acquisition systems designed to increase reliability and timeliness of geomagnetic measurements had replaced nearly all legacy USGS observatory systems by the close of FY23. In addition, and in collaboration with the USGS Albuquerque Seismological Laboratory, low-cost off-the-shelf magnetic variometers have been co-deployed at a significant subset of existing seismic monitoring stations, with a focus on improving near real time geomagnetic data coverage of the conterminous United States (CONUS). Starting in 2020, Congress appropriated funds to the USGS to complete a long-period magnetotelluric (MT) survey of CONUS, a project initiated by the National Science Foundation's EarthScope program (2006-2018), and subsequently supported by NASA (2019). The MT survey is expected to be completed in 2024. Geomagnetism Program staff perform quality control, processing, and archival of the MT survey data, as well as develop software for interpretation of MT data in terms of solid-Earth electrical conductivity structure, and they produce models of the Earth’s electrical conductivity and surface impedance. The Geomagnetism Program works closely with the Space Weather Prediction Center of the National Oceanic and Atmospheric Administration (NOAA) to support, validate, and improve their real-time geoelectric field mapping capability by integrating the latest and highest quality geomagnetic and MT data and modeling. All such efforts improve scientific understanding of, and the ability to mitigate, hazards that impact critical infrastructure like high-voltage electric power distribution grids.