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 5, 2019

New U.S. Geological Survey Report Assesses Risk of Once-Per-Century Geomagnetic Superstorm to the Northeastern 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.  

Date published: September 18, 2018

Science for a Risky World: A USGS Plan for Risk Research and Applications – USGS publishes strategic plan for examining risk

USGS explores opportunities to advance its capabilities in risk assessment, mitigation, and communication in new strategic plan.

Date published: September 18, 2018

USGS Science – Leading the Way for Preparedness

Learn About USGS Hazards Science and More About National Preparedness Month: The very nature of natural hazards means that they have the potential to impact a majority of Americans every year.  USGS science provides part of the foundation for emergency preparedness whenever and wherever disaster strikes.

Publications

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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: 2018

Extreme‐value geoelectric amplitude and polarization across the northeast United States

Maps are presented of extreme‐value geoelectric field amplitude and horizontal polarization for the Northeast United States. These maps are derived from geoelectric time series calculated for sites across the Northeast by frequency‐domain multiplication (time‐domain convolution) of 172 magnetotelluric impedance tensors, acquired during a survey,...

Love, Jeffrey J.; Lucas, Greg M.; Bedrosian, Paul A.; Kelbert, Anna

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Year Published: 2018

On the intensity of the magnetic superstorm of September 1909

Analysis is made of solar observations and ground‐based magnetometer data recording space weather before and during the magnetic superstorm of 25 September 1909. From these data, it is inferred that the storm was initiated by an interplanetary coronal‐mass ejection having a mean Sun‐to‐Earth velocity of ~1,679 km/s. The commencement pressure...

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