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.

Rocks Under I-95 Present Odd, and Scary, Threat to Power Grid

Rocks Under I-95 Present Odd, and Scary, Threat to Power Grid

A soon-to-be-published USGS publication points out geomagnetic hazards in the Eastern U.S. (Bloomberg News Story)

Read the story.

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)

Read the story.

New 3D Measurements Improve Understanding of Geomagnetic Storm Hazards

New 3D Measurements Improve Understanding of Geomagnetic Storm Hazards

Measurements of the three-dimensional structure of the earth, as opposed to the one-dimensional models typically used, can help scientists more accurately determine which areas of the United States are most vulnerable to blackouts during hazardous geomagnetic storms.

Read story.

News

Date published: August 8, 2018

Mapping Extreme-Value Geoelectric Fields

To help mitigate magnetic storm interference on electric power grid operations, extreme-value geoelectric fields have been mapped across the mid-Atlantic United States. (EOS article) Read Article.

Date published: March 8, 2018

New 3D Measurements Improve Understanding of Geomagnetic Storm Hazards

Measurements of the three-dimensional structure of the earth, as opposed to the one-dimensional models typically used, can help scientists more accurately determine which areas of the United States are most vulnerable to blackouts during hazardous geomagnetic storms.

Date published: September 6, 2017

USGS Science Leads the Way for National Preparedness

With hurricanes in the east and wildfires in the west, natural hazards 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.

Filter Total Items: 37
Date published: August 8, 2018
Status: Active

Abstracts

A list of abstracts from 1998 to 2017.

Date published: August 7, 2018
Status: Active

More Examples

More example requests:

Date published: August 7, 2018
Status: Active

Web Service

Example Requests

BOU observatory data for current UTC day in IAGA2002 format
http://geomag.usgs.gov/ws/edge/?id=BOU
BOU observatory data for current UTC day in JSON format
http://geomag.usgs.gov/ws/edge/?id=BOU&
...
Date published: August 7, 2018
Status: Active

Download Real-Time Data

USGS Geomagnetism Program data are made available as-is and without any guarantees of continuity and quality.

Date published: July 31, 2018
Status: Active

Overview

Space climatology is concerned with longer-term changes in the space environment that are driven almost entirely by changes in solar output. 

Contacts: Jeffrey J Love
Date published: July 25, 2018
Status: Active

Introduction to Geomagnetism

Geomagnetism is the study of the Earth's magnetic field. This includes the fields produced by the Earth as well as those interacting with the Earth. Internal dynamo processes within the Earth create slowly changing magnetic fields. The continuous flow of particles and fields from the Sun (called the solar wind) interacts with the Earth's magnetic field. Strong, transient impulses due to solar...

Contacts: Jeffrey J Love
Date published: July 25, 2018
Status: Active

Space Climatoloy

Space climatology is concerned with longer-term changes in the space environment that are driven almost entirely by changes in solar output. 

Contacts: Jeffrey J Love
Attribution: Geomagnetism
Date published: July 25, 2018
Status: Active

More info - Space Weather Applications

USGS-Dst Index, Electric Field Estimates, Pulsation Indices

Date published: July 25, 2018
Status: Active

Overview

Examples of extreme-event work published by USGS scientists are on the Publications tab.

    Contacts: Jeffrey J Love
    Date published: July 23, 2018
    Status: Active

    Tucson (TUC)

    The Geomagnetism Program first established an observatory near Tucson in 1910 on what is now Morris K. Udall Regional Park. The current site, in the Saguaro National Park, was installed in 1996.

     

    Magnetic monitoring in Saguaro National Park (FS-2017-3035)

    Date published: July 23, 2018
    Status: Active

    San Juan (SJG)

    The Geomagnetism Program has operated an observatory at Puerto Rico since 1903. The current observatory site, consisting of 36 acres in the mountains near Cayey, has been in use since 1965.

    Date published: July 23, 2018
    Status: Active

    Sikta (SIT)

    Prior to the purchase of Alaska by the United States, the Russians operated a meteorological and magnetic observatory at Sitka from 1842 to 1867. The Geomagnetism Program established an observatory at Sitka, near the historic Russian cemetery, in 1901, when the Program was part of the Coast and Geodetic Survey and under the leadership of Drs Louis A. Bauer and John A. Fleming. The present...

    Filter Total Items: 7
    Date published: July 27, 2018

    Geomagnetism Plots

    Real-time display of USGS geomagnetic observatory data feeds and derived products.

    Date published: July 25, 2018

    Download Real-Time Data

    Download real-time and definitive data and indices from USGS geomagnetic observatories.

    Date published: July 23, 2018

    Magnetic Disturbance Events

    View reports on magnetic disturbance events.

    Date published: July 21, 2018

    Models

    View and download model results from magnetic studies.

    Date published: July 19, 2018

    Real-Time Disturbance Storm Time (Dst) Display

    Real-time Dst data from USGS observatories as well as other world partners.

    Date published: July 18, 2018

    Magnetic Disturbance Movies

    Movie-maps of low-latitude horizontal-intensity magnetic disturbance are derived from magnetic vector time series data collected at multiple ground-based observatories. Using a technique similar to that used in the calculation of Dst, a quiet time baseline is subtracted from the time series from each observatory. The remaining disturbance time series are shown in a polar coordinate system that...

    Date published: July 17, 2018

    Other Sources of Data

    Looking for more data?

    Attribution: Geomagnetism
    Filter Total Items: 2
    Date published: October 16, 2017

    Regional Conductivity Maps

    Location of 1D Earth Resistivity Models with respect to Physiographic Regions of the USA

    Date published: March 7, 2016

    Observatories

    Map of USGS Magnetic observatory locations.

    Filter Total Items: 370
    Year Published: 2018

    On the feasibility of real-time mapping of the geoelectric field across North America

    A review is given of the present feasibility for accurately mapping geoelectric fields across North America in near-realtime by modeling geomagnetic monitoring and magnetotelluric survey data. Should this capability be successfully developed, it could inform utility companies of magnetic-storm interference on electric-power-grid systems. That real...

    Love, Jeffrey J.; Rigler, E. Joshua; Kelbert, Anna; Finn, Carol A.; Bedrosian, Paul A.; Balch, Christopher C.
    Love, J.J., Rigler, E.J., Kelbert, Anna, Finn, C.A., Bedrosian, P.A., and Balch, C.C., 2018, On the feasibility of real-time mapping of the geoelectric field across North America: U.S. Geological Survey Open-File Report 2018-1043, 16 p., https://doi.org/10.3133/ofr20181043.

    Year Published: 2018

    Geoelectric hazard assessment: the differences of geoelectric responses during magnetic storms within common physiographic zones

    Geomagnetic field data obtained through the INTERMAGNET program are convolved with with magnetotelluric surface impedance from four EarthScope USArray sites to estimate the geoelectric variations throughout the duration of a magnetic storm. A duration of time from June 22, 2016, to June 25, 2016, is considered which encompasses a...

    Cuttler, Stephen W.; Love, Jeffrey J.; Swidinsky, Andrei
    Cuttler, S. W., Love, J. J. & Swidinsky, A., 2018. Geoelectric hazard assessment: the differences of geoelectric responses during magnetic storms within common physiographic zones, Earth Planets Space, 70, 35, doi:10.1186/s40623-018-0807-7.

    Year Published: 2018

    Calculation of voltages in electric power transmission lines during historic geomagnetic storms: An investigation using realistic earth impedances

    Commonly, one-dimensional (1-D) Earth impedances have been used to calculate the voltages induced across electric power transmission lines during geomagnetic storms under the assumption that much of the three-dimensional structure of the Earth gets smoothed when integrating along power transmission lines. We calculate the voltage across power...

    Lucas, Greg M.; Love, Jeffrey J.; Kelbert, Anna
    Lucas, G. M., Love, J. J., & Kelbert, A. (2018). Calculation of voltages in electric power transmission lines during historic geomagnetic storms: An investigation using realistic earth impedances. Space Weather, 16. https://doi.org/10.1002/2017SW001779

    Year Published: 2018

    Geoelectric hazard maps for the Mid-Atlantic United States: 100 year extreme values and the 1989 magnetic storm

    Maps of extreme value geoelectric field amplitude are constructed for the Mid‐Atlantic United States, a region with high population density and critically important power grid infrastructure. Geoelectric field time series for the years 1983–2014 are estimated by convolving Earth surface impedances obtained from 61 magnetotelluric survey sites...

    Love, Jeffrey J.; Lucas, Greg M.; Kelbert, Anna; Bedrosian, Paul A.
    Love, J. J., Lucas, G. M., Kelbert, A. & Bedrosian, P. A., 2018. Geoelectric hazard maps for the Mid-Atlantic United States: 100 year extreme values and the 1989 magnetic storm, Geophys. Res. Lett., 45(1), 5-15, doi:10.1002/2017GL076042.

    Year Published: 2018

    Extreme-event geoelectric hazard maps: Chapter 9

    Maps of geoelectric amplitude covering about half the continental United States are presented that will be exceeded, on average, once per century in response to an extreme-intensity geomagnetic disturbance. These maps are constructed using an empirical parameterization of induction: convolving latitude-dependent statistical maps of extreme-value...

    Love, Jeffrey J.; Bedrosian, Paul A.

    Year Published: 2018

    The electric storm of November 1882

    In November 1882, an intense magnetic storm related to a large sunspot group caused widespread interference to telegraph and telephone systems and provided spectacular and unusual auroral displays. The (ring current) storm time disturbance index for this storm reached maximum −Dst ≈ 386 nT, comparable to Halloween storm of 29–31...

    Love, Jeffrey J.
    Love, J. J. (2018). The electric storm of November 1882. Space Weather, 16, 37–46. https://doi.org/10.1002/2017SW001795.

    Year Published: 2017

    Geoelectric monitoring at the Boulder magnetic observatory

    Despite its importance to a range of applied and fundamental studies, and obvious parallels to a robust network of magnetic-field observatories, long-term geoelectric field monitoring is rarely performed. The installation of a new geoelectric monitoring system at the Boulder magnetic observatory of the US Geological Survey is summarized. Data from...

    Blum, Cletus; White, Tim; Sauter, Edward A.; Stewart, Duff; Bedrosian, Paul A.; Love, Jeffrey J.
    Blum, C. C., White, T. C., Sauter, E. A., Stewart, D. C., Bedrosian, P. A., and Love, J. J.: Geoelectric monitoring at the Boulder magnetic observatory, Geosci. Instrum. Method. Data Syst. Discuss., https://doi.org/10.5194/gi-2017-27, in production, 2017.

    Year Published: 2017

    U.S. Geological Survey experience with the residual absolutes method

    The U.S. Geological Survey (USGS) Geomagnetism Program has developed and tested the residual method of absolutes, with the assistance of the Danish Technical University's (DTU) Geomagnetism Program. Three years of testing were performed at College Magnetic Observatory (CMO), Fairbanks, Alaska, to compare the residual method...

    Worthington, E. William; Matzka, Jurgen
    Worthington, E. W. and Matzka, J.: U.S. Geological Survey experience with the residual absolutes method, Geosci. Instrum. Method. Data Syst., 6, 419-427, https://doi.org/10.5194/gi-6-419-2017, 2017.

    Year Published: 2017

    Methodology for time-domain estimation of storm time geoelectric fields using the 3-D magnetotelluric response tensors

    Geoelectric fields at the Earth's surface caused by magnetic storms constitute a hazard to the operation of electric power grids and related infrastructure. The ability to estimate these geoelectric fields in close to real time and provide local predictions would better equip the industry to mitigate negative impacts on their operations. Here we...

    Kelbert, Anna; Balch, Christopher; Pulkkinen, Antti; Egbert, Gary D; Love, Jeffrey J.; Rigler, E. Joshua; Fujii, Ikuko
    Kelbert, A., Balch, C. C., Pulkkinen, A., Egbert, G. D., Love, J. J., Rigler, E. J., & Fujii, I. (2017). Methodology for time-domain estimation of storm time geoelectric fields using the 3-D magnetotelluric response tensors. Space Weather, 15(7), 874-894.

    Year Published: 2017

    Geomagnetically induced currents: Science, engineering, and applications readiness

    This paper is the primary deliverable of the very first NASA Living With a Star Institute Working Group, Geomagnetically Induced Currents (GIC) Working Group. The paper provides a broad overview of the current status and future challenges pertaining to the science, engineering, and applications of the GIC problem. Science is understood here as the...

    Pulkkinen, Antti; Bernabeu, E.; Thomson, A.; Viljanen, A.; Pirjola, R.; Boteler, D.; Eichner, J.; Cilliers, P.J.; Welling, D.; Savani, N.P.; Weigel, R.S.; Love, Jeffrey J.; Balch, Christopher; Ngwira, C.M.; Crowley, G.; Schultz, Adam; Kataoka, R.; Anderson, B.; Fugate, D.; Simpson, J.J.; MacAlester, M.
    Pulkkinen, A., et al. (2017), Geomagnetically induced currents: Science, engineering, and applications readiness, Space Weather, 15, doi:10.1002/2016SW001501.

    Year Published: 2017

    Real-time geomagnetic monitoring for space weather-related applications: Opportunities and challenges

    An examination is made of opportunities and challenges for enhancing global, real-time geomagnetic monitoring that would be beneficial for a variety of operational projects. This enhancement in geomagnetic monitoring can be attained by expanding the geographic distribution of magnetometer stations, improving the quality of magnetometer data,...

    Love, Jeffrey J.; Finn, Carol
    Love, J. J., and C. A. Finn (2017), Real-time geomagnetic monitoring for space weather-related applications: Opportunities and challenges, Space Weather, 15, doi:/10.1002/2017SW001665.

    Year Published: 2017

    Magnetic monitoring in Saguaro National Park

    On a sandy, arid plain, near the Rincon Moun­tain Visitor Center of Saguaro National Park, tucked in among brittlebush, creosote, and other hardy desert plants, is an unusual type of observatory—a small unmanned station that is used for monitor­ing the Earth’s variable magnetic field. Named for the nearby city of Tucson, Arizona, the observatory...

    Love, Jeffrey J.; Finn, Carol; Gamez Valdez, Yesenia C.; Swann, Don
    Love, J.J., Finn, C.A., Gamez Valdez, Y.C., Swann, Don, 2017, Magnetic monitoring in Saguaro National Park: U.S. Geological Survey Fact Sheet 2017–3035, 2 p., https://doi.org/10.3133/fs20173035.

    Filter Total Items: 11
    Image: Guam Geomagnetic Observatory
    August 8, 2011

    Guam Geomagnetic Observatory

    Guam geomagnetic observatory.

    Attribution: Geomagnetism
    Image: Guam Geomagnetic Observatory

    Guam Geomagnetic Observatory

    Variations building at Guam geomagnetic observatory.

    Attribution: Geomagnetism
    Image: Guam Geomagnetic Observatory

    Guam Geomagnetic Observatory

    Nema box at Guam geomagnetic observatory.

    Attribution: Geomagnetism
    Image: Guam Geomagnetic Observatory

    Guam Geomagnetic Observatory

    Kat Uchima at Guam geomagnetic observatory.

    Attribution: Geomagnetism
    USGS
    May 20, 1956

    Geodetic Survey Set to Dedicate Observatory

    From The Washington Post and Times Herald.

    USGS
    May 23, 1956

    U. S. DEPARTMENT OF COMMERCE COAST & GEODETIC SURVEY

    Fredericksburg Magnetic Observatory and Laboratory Corbin, Virginia.

    USGS
    July 23, 2018

    New Magnetic Observatory at Ewa

    Construction is now in progress on a new magnetic observatory for the U.S. Coast and Geodetic Survey near Ewa. It will serve as the nerve center for magnetic observations and will be the heart of the seismic wave warning system in the Pacific area.

    USGS
    August 3, 2018

    Geomagnetic Observatory Locations

    Explore all of the USGS Geomagnetic Observatories with this Google EarthTM download

    Filter Total Items: 9
    Date published: August 8, 2018

    Mapping Extreme-Value Geoelectric Fields

    To help mitigate magnetic storm interference on electric power grid operations, extreme-value geoelectric fields have been mapped across the mid-Atlantic United States. (EOS article) Read Article.

    Date published: March 8, 2018

    New 3D Measurements Improve Understanding of Geomagnetic Storm Hazards

    Measurements of the three-dimensional structure of the earth, as opposed to the one-dimensional models typically used, can help scientists more accurately determine which areas of the United States are most vulnerable to blackouts during hazardous geomagnetic storms.

    Date published: September 6, 2017

    USGS Science Leads the Way for National Preparedness

    With hurricanes in the east and wildfires in the west, natural hazards 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.

    Date published: May 1, 2017

    Preparing the Nation for Intense Space Weather

    While major geomagnetic storms are rare, with only a few recorded per century, there is significant potential for large-scale impacts when they do occur. Extreme space weather can be viewed as hazards for the economy and national security.

    Date published: September 12, 2016

    Mapping a Space-Weather Menace to Electric-Power Grids

    New strides have been made toward quantifying how geomagnetic storms can interfere with the nation’s electric-power grid systems.  

    Date published: September 1, 2016

    September is National Preparedness Month

    September is National Preparedness Month, a time to highlight the resources available to help you and your loved ones stay as safe as possible. 

    Date published: January 7, 2016

    Getting Down to Earth with Space Hazards

    Magnetic storms can interfere with the operation of electric power grids and damage grid infrastructure. They can also disrupt directional drilling for oil and gas, radio communications, communication satellites and GPS systems.

    Date published: September 30, 2015

    Aurora Borealis Painting Pays Tribute to Civil War’s End

    USGS explores the meaning behind Frederic Edwin Church's 1865 painting, “Aurora Borealis.”

    Date published: September 28, 2015

    Join America’s PrepareAthon! Practice what to do in the event of a disaster or emergency.

    Join millions of people participating in America’s PrepareAthon! on Sept. 30. This campaign encourages the nation to conduct drills, discussions and exercises to practice what to do before, during and after a disaster or emergency strikes.