Geomagnetism - 22 of 21
Geomagnetism FAQs - 21 Found
The infrastructure and activities of our modern technologically-based society can be adversely affected by rapid magnetic-field variations generated by electric currents in the near-Earth space environment, particularly in the ionosphere and magnetosphere. This is especially true during so-called "magnetic storms."
- Because the ionosphere is heated and distorted during storms, long-range radio communication which relies on sub-ionospheric reflection can be difficult or impossible and global-positioning system (GPS) communications, which relies on radio transmission through the ionosphere, can be degraded.
- Ionospheric expansion can enhance satellite drag and thereby make their orbits difficult to control.
- During magnetic storms, satellite electronics can be damaged through the build up and subsequent discharge of static-electric charges, and astronaut and high-altitude pilots can be subjected to increased levels of radiation.
- There can even be deleterious effects on the ground: pipe-line corrosion can be enhanced and electric-power grids can experience voltage surges that cause blackouts.
The reason why space-based effects can have consequences down here on the Earth's surface is related, at least in part, to our answer to another frequently asked question, "What is a magnetic field?." Electric currents in one place can induce electric currents in another place. This action at a distance is accomplished via a magnetic field. So, even though rapid magnetic-field variations are generated by currents in space, very real effects, such as unwanted electric currents induced in electric-power grids, can result down here on the Earth’s surface.
Learn more: about the hazardous effects associated with geomagnetic activity at the USGS National Geomagnetism Program Further Reading Web page.