How does the Earth's core generate a magnetic field?
The Earth's outer core is in a state of turbulent convection as the result of radioactive heating and chemical differentiation. This sets up a process that is a bit like a naturally occurring electrical generator, where the convective kinetic energy is converted to electrical and magnetic energy. Basically, the motion of the electrically conducting iron in the presence of the Earth's magnetic field induces electric currents. Those electric currents generate their own magnetic field, and as the result of this internal feedback, the process is self-sustaining so long as there is an energy source sufficient to maintain convection.
Learn more:
Related Content
Why measure the magnetic field at the Earth's surface? Wouldn't satellites be better suited for space-weather studies?
What are the hazards of magnetic storms?
What is a magnetic storm?
Does the Earth's magnetic field affect human health?
What is declination?
Are we about to have a magnetic reversal?
Is the Earth a magnet?
Geomagnetism Program research plan, 2020–2024
The Geomagnetism Program of the U.S. Geological Survey (USGS) monitors geomagnetic field variation through operation of a network of observatories across the United States and its territories, and it pursues scientific research needed to estimate and assess geomagnetic and geoelectric hazards. Over the next five years (2020–2024 inclusive) and in...
Love, Jeffrey J.; Kelbert, Anna; Murphy, Benjamin S.; Rigler, E. Joshua; Lewis, Kristen A.
The Boulder magnetic observatory
The Boulder magnetic observatory has, since 1963, been operated by the Geomagnetism Program of the U.S. Geological Survey in accordance with Bureau and national priorities. Data from the observatory are used for a wide variety of scientific purposes, both pure and applied. The observatory also supports developmental projects within the...
Love, Jeffrey J.; Finn, Carol A.; Pedrie, Kolby L.; Blum, Cletus C.
Monitoring the Earth's dynamic magnetic field
The mission of the U.S. Geological Survey's Geomagnetism Program is to monitor the Earth's magnetic field. Using ground-based observatories, the Program provides continuous records of magnetic field variations covering long timescales; disseminates magnetic data to various governmental, academic, and private institutions; and conducts research...
Love, Jeffrey J.; Applegate, David; Townshend, John B.
Introduction to Potential Fields: Magnetics
This dynamic earth: the story of plate tectonics
In the early 1960s, the emergence of the theory of plate tectonics started a revolution in the earth sciences. Since then, scientists have verified and refined this theory, and now have a much better understanding of how our planet has been shaped by plate-tectonic processes. We now know that, directly or indirectly, plate tectonics...
Kious, W. Jacquelyne; Tilling, Robert I.
Geomagnetism applications
The social uses of geomagnetism include the physics of the space environment, satellite damage, pipeline corrosion, electric power-grid failure, communication interference, global positioning disruption, mineral-resource detection, interpretation of the Earth's formation and structure, navigation, weather, and magnetoreception in organisms. The...
Campbell, Wallace H.
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.
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.
USGS, NOAA Mark 50 Years of Geomagnetic Research at Corbin, Va.
On May 23, 1956, a research center and observatory opened at Corbin, Va. to continuously monitor the Earth's magnetic field. It was charged by Congress "to enhance geomagnetic field studies and monitoring programs in support of scientific, general public, basic and national security needs of the United States."
Preparing the Nation for Intense Space Weather
Preparing the Nation for Intense Space Weather
Giant Sunspot Erupts on October 24, 2014
Active Region 12192 on the sun erupted with a strong flare on October 24, 2014, prominent in the bright light of this image captured by NASA's Solar Dynamics Observatory. This image shows extreme ultraviolet light that highlights the hot solar material in the sun's atmosphere. Credit: NASA
Hazards: Geomagnetic Storms
Space weather can have important consequences for our lives, such as interference with radio communication, GPS systems, electric power grids, the operation and orientation of satellites, oil and gas drilling, and even air travel as high altitude pilots and astronauts can be subjected to enhanced levels of radiation. It is also during magnetic storms that beautiful aurora
Earth Science Week, Continued: Geomagnetism and the Self-Sustaining Dynamo Called Earth
USGS scientist Duane Champion explains the Earth's geomagnetic qualities and the potential for and possible consequences of a geomagnetic shift.
PubTalk 7/2004 — Secrets in Stone
The Role of Paleomagnetism in the Evolution of Plate Tectonic Theory Video Presentation
Presentation of the award-winning USGS video "Secrets in Stone" (35 minutes), introduced by Jack Hillhouse, Research Geophysicist, and followed by a tour of the USGS Paleomagnetics Laboratory
- Crucial discoveries in the early 1960.s were made
