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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The Electric Storm of November 1882

The Electric Storm of November 1882

Strange things started happening on November 17, 1882, and no one knew quite what to make of it.(image from Baranyi et al., 2016)

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News

Date published: March 16, 2020

New Geoelectric Hazard Map Shows Potential Vulnerability to High-Voltage Power Grid for Two-Thirds of the US

The U.S. Geological Survey released a new report on geoelectric hazards for two-thirds of the contiguous U.S., spanning from the northeast to the west coast of the Nation. 

Date published: December 5, 2019

Airplane to Make Low-Level Flights Over Parts of the Eastern Mojave Desert, California and Nevada

For about two months, starting around December 7, 2019, an airplane operated under contract to the USGS will be making low-level flights over parts of the eastern Mojave Desert.

Publications

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Year Published: 2019

Intensity and impact of the New York Railroad superstorm of May 1921

Analysis is made of low‐latitude ground‐based magnetometer data recording the magnetic superstorm of May 1921. By inference, the storm was driven by a series of interplanetary coronal mass ejections, one of which produced a maximum pressure on the magnetopause of ~64.5 nPa, sufficient to compress the subsolar magnetopause radius to ~5.3 Earth...

Love, Jeffrey J.; Hayakawa, Hisashi; Cliver, Edward W.

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Year Published: 2019

Data sharing in magnetotellurics

Here, we introduce the first openly available comprehensive database of magnetotelluric (MT) and related electromagnetic data that we developed and matured over the past decade, explain how to access the data, and describe the challenges that had to be overcome to make MT data sharing possible. The database is a helpful tool for MT scientists, and...

Kelbert, Anna; Erofeeva, Svetlana; Trabant, Chad; Karstens, Rich; Van Fossen, Mickey C.

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Year Published: 2019

The extreme space weather event in September 1909

We evaluate worldwide low-latitude auroral activity associated with the great magnetic storm of September 1909 for which a minimum Dst value of −595 nT has recently been determined. From auroral observations, we calculate that the equatorward boundary of the auroral oval in the 1909 event was in the range from 31°–35° invariant latitude (...

Hayakawa, Hisashi; Ebihara, Yusuke; Cliver, Edward W.; Hattori, Kentaro; Toriumi, Shin; Love, Jeffrey J.; Umemura, Norio; Namekata, Kosuke; Sakaue, Takahito; Takahashi, Takuya; Shibata, Kazunari