Geomagnetism

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We monitor the Earth's magnetic field. Using ground-based observatories, we provide continuous records of magnetic field variations; disseminate magnetic data to various governmental, academic, and private institutions; and conduct research into the nature of geomagnetic variations for purposes of scientific understanding and hazard mitigation.

Keeping the Lights On in North America

Keeping the Lights On in North America

Realtime geoelectric maps during a magnetic storm can assist utility companies with their operations and can help power-grid managers to make decisions that may minimize the impact to their systems.

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Risk of Once-Per-Century Geomagnetic Superstorm in NE United States

Risk of Once-Per-Century Geomagnetic Superstorm in NE United States

A new report and map published by the U.S. Geological Survey provides critical insight to electric power grid operators across the northeastern United States in the event of a once-per-century magnetic superstorm.  

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Auroras and Earthquakes: Strange Companions

Auroras and Earthquakes: Strange Companions

In a win-win situation for both seismologists and space physicists, a cheap magnetometer at a seismic station can result in better seismic data for earthquakes and also more geomagnetic data in real time for monitoring space weather.

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News

Date published: July 22, 2021

Down to Earth: Complexities of Geology Affect Nuclear Electromagnetic Pulse Hazard 

Geoelectric hazards generated by a nuclear explosion at the outer edge of Earth’s atmosphere can be strongly affected by the electrical conductivity of rock structures beneath the Earth's surface, according to a study led by the U.S. Geological Survey.  

March 26, 2021

The Monitor newsletter - Vol. 2 | Issue Spring 2021

In this issue: When will Mauna Loa next Erupt?, ShakeOut rollout to the Pacific Northwest, Big Sur Landslides, new storymaps for earthquakes and wildfire science, expanding coverage of the "Total Water Level and Coastal Change Forecast" tools, New Reducing Risk 2021 projects, and more.

Publications

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Year Published: 2021

Geomagnetic monitoring in the mid-Atlantic United States

Near historic battlegrounds of the American Civil War, southeast of Fredericksburg, Virginia, on a secluded grassy glade surrounded by forest, a specially designed observatory records the Earth’s changing magnetic field. This facility, the Fredericksburg Magnetic Observatory, is 1 of 14 observatories the U.S. Geological Survey Geomagnetism Program...

Love, Jeffrey J.; Lewis, Kristen A.
Love, J.J., and Lewis, K.A., 2021, Geomagnetic monitoring in the mid-Atlantic United States: U.S. Geological Survey Fact Sheet 2021-3001, 2 p., https://doi.org/10.3133/fs20213001.

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Year Published: 2021

Electrical conductivity of the lithosphere-asthenosphere system

Electromagnetic geophysical methods image the electrical conductivity of the subsurface. Electrical conductivity is an intrinsic material property that is sensitive to temperature, composition, porosity, volatile and/or melt content, and other physical properties relevant to the solid Earth. Therefore, imaging the electrical structure of...

Naif, Samer; Selway, Kate; Murphy, Benjamin Scott; Egbert, Gary D.; Pommier, Anne

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Year Published: 2020

Simultaneous observations of geoelectric and geomagnetic fields produced by magnetospheric ULF waves

Geomagnetic perturbations (BGEO) related to magnetospheric ultralow frequency (ULF) waves induce electric fields within the conductive Earth—geoelectric fields (EGEO)—that in turn drive geomagnetically induced currents. Though numerous past studies have examined ULF wave BGEO from a space weather perspective, few studies have linked ULF...

Hartinger, M. D.; Shih, X. R.; Lucas, G.; Murphy, Benjamin Scott; Kelbert, Anna; Baker, J.B.H.; Rigler, E. Joshua; Bedrosian, Paul A.