A telluric current is a extremely low frequency electrical current that occurs naturally over large underground areas at or near the surface of the Earth. Extremely low frequency (ELF) is the band of radio frequencies from 3 to 300 Hz. ... In electricity, current is the rate of flow of charges, usually through a metal wire or some other electrical conductor. ... The word ground has several meanings: The surface of the Earth Soil, a mixture of sand and organic material present on the surface of the Earth Ground (electricity), in electrical engineering, something that is connected to the Earth or at the voltage defined as zero (in the US, called ground... Earth, also known as Terra, and (mostly in the 19th century) Tellus, is the third-closest planet to the Sun. ...

Description

Telluric currents are induced in the Earth's crust and mantle by changes in the outer part of the Earth's magnetic field, which are usually caused by interactions between the solar wind and the ionosphere. They also result from thunderstorms. The electric potential on the Earth's surface can be measured at different points, enabling us to calculate the magnitudes and directions of the telluric currents and thence the Earth's conductance. Electric potential gradients caused by telluric currents are of the order of 10 microvolts per metre. In geology, a crust is the outer layer of a planet, part of its lithosphere. ... A Mantle is a piece of clothing, similar to a robe but open on the front side and often sleeveless. ... The magnetosphere shields the surface of the Earth from the charged particles of the solar wind. ... The plasma in the Solar Wind meeting the heliopause Ion storm redirects here. ... The ionosphere is the part of the atmosphere that is ionized by solar radiation. ... A roll cloud associated with a heavy or severe thunderstorm over Enschede, The Netherlands. ... Conductance can refer to: Electrical conductance, the reciprocal of electrical resistance. ...

Both the telluric and magnetotelluric methods are used for exploring the structure beneath Earth's surface (such as in industrial prospecting). For mineral exploration the targets are conductive ore bodies. Other uses include exploration of geothermal fields, petroleum reservoirs, fault zones, ground water, magma chambers, and plate tectonic boundaries. This article is about minerals in the geologic sense; for nutrient minerals see dietary mineral; for the band see Mineral (band). ... Iron ore (Banded iron formation) Manganese ore Lead ore Gold ore An ore is a mineral deposit containing a metal or other valuable resource in economically viable concentrations. ... Geothermal power is electricity generated by utilizing naturally occurring geological heat sources. ... Nodding donkey pumping an oil well near Sarnia, Ontario, 2001 Petroleum (from Latin petra – rock and oleum – oil), crude oil, sometimes colloquially called black gold, is a thick, dark brown or greenish liquid. ... Magma is molten rock often located inside a magma chamber beneath the surface of the Earth. ... The tectonic plates of the world were mapped in the second half of the 20th century. ...

Patents

The United States Patent office has a division classification for geophysical electrical measuring devices of the telluric type (including magneto-telluric types).

See also

• High-voltage direct current
• Earth's magnetic field
• Ley line
• Wardenclyffe Tower Magnifying Transmitter
• Earth battery

HVDC or high-voltage, direct current electric power transmission systems contrast with the more common alternating-current systems as a means for the bulk transmission of electrical power. ... The magnetosphere shields the surface of the Earth from the charged particles of the solar wind. ... Ley lines are alignments of a number of places of geographical interest, such as ancient megaliths. ... This article is in need of attention from an expert in the following subjects: Nikola Teslas inventions, Teslas patents, electrical engineering, and physics. ... A publicity photo of Tesla sitting in the Colorado Springs experimental station with his Magnifying Transmitter. The arcs are about 22 feet (7 m) long. ... An earth battery is an early type of voltaic cell buried in the ground so that the soil acts as the electrolyte. ...

Patents

• U.S. Patent 3361957 - Telluric current responsive device having spaced conductors for positioning adjacent the Earth's surface - D. L. Hings

Further reading

• Gideon, D. N., A. T. Hopper, and R. E. Thompson, "Earth current effects on buried pipelines : analysis of observations of telluric gradients and their effects". Battelle Memorial Institute and the American Gas Association. New York, 1970.

Reference

• "telluric current" A Dictionary of Earth Sciences. Ed. Ailsa Allaby and Michael Allaby. Oxford University Press, 1999.

External links

• Scripps Institution of Oceanography Marine EM Laboratory .
• Stephen, Jimmy, S. G. Gokarn, C. Manoj, S. B. Singh, "Effects of galvanic distortions on magnetotelluric data: Interpretation and its correction using deep electrical data". National Geophysical Research Institute. (PDF)
• Gummow, R. A., "Telluric and Ocean Current Effects on Buried Pipeline and their Cathodic Protection Systems". CORRENG Consulting Service, Inc. December 03, 2002.
• Sinha, M. C., et. al., "Applications of 3-Dimensional Electromagnetic Induction by Sources in the Ocean, ISO-3D". RTD Project, MAST III (Area C: Marine Technology). MAS3-CT97-0120