A telluric current
(from Latin tellūs
"earth") is an electric current
which moves underground or through the sea. Telluric currents
result from both natural causes and human activity, and the
discrete currents interact in a complex pattern. The currents are
extremely low frequency
travel over large areas at or near the surface of Earth
Telluric currents are phenomena observed in the Earth's crust
. In September 1862, an experiment to
specifically address Earth currents was carried out in the Munich
Alps (Lamont, 1862). The currents are primarily induced by changes
in the outer part of the Earth's
, which are usually caused by interactions
between the solar wind
and the magnetosphere
or solar radiation effects on
. Telluric current activity
is related to thunderstorms
, and recent
research indicates that by causing accumulation of electrical
charge on the Earth's surface, they play a vital role in turning a
rain shower into a thunder storm. Telluric currents flow in the
surface layers of the earth. 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
These currents are known to have diurnal
characteristics wherein the general direction of flow is towards
the sun. Telluric currents will move between each half of the
terrestrial globe at all times. Telluric currents move equator-ward
(daytime) and pole-ward (nighttime).
Both the telluric and magnetotelluric
methods are used for
exploring the structure beneath the Earth's surface (such as in
industrial prospecting). For mineral
exploration the targets are conductive ore
bodies. Other uses include exploration of geothermal
reservoirs, fault zones, ground water,
chambers, and plate tectonic
boundaries. Telluric currents
can be harnessed to produce a useful low voltage current by means
of earth batteries
. Such devices were
used for telegraph
systems in the United
States as far back as 1859.
In industrial prospecting
activity that uses the telluric
current method, electrodes
located on the ground to sense the voltage difference
caused by the oscillatory
currents. It is recognized that a low frequency window
(LFW) exists when
telluric currents pass through the earth's substrata
. In the frequencies of
the LFW, the earth acts as a conductor
The main plot of the novel Foucault's Pendulum
by Umberto Eco
revolves around search of the
(Latin: The Navel of the World), the
mystic Center of The Earth
which is supposed to be a
certain point from where a person could control the energies and
shapes of the earth thus reforming it at will. The novel takes this
even further by suggesting that monuments like the Eiffel Tower are nothing more than giant antennae to catalyze these
Telluric currents are also used as a means of travel by the woman
Hsien-Ko and her minions in the Doctor
"Missing Adventures" novel, The Shadow of Weng-Chiang
David A McIntee.
Telluric currents – along what are effectively ley lines
– are discovered to be a means of
mysterious communication in Thomas Pynchon's Mason and Dixon
and are associated with the
book's Chinese-Jesuit sub plot. As with Eco, cited above, Pynchon
also reflects upon hollow earth theories in this work.
- , D. L. Hings, Telluric current responsive device having spaced
conductors for positioning adjacent the Earth's surface
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- Dobrin, "Introduction to Geophysical Prospecting",
McGraw Hill (3rd Ed. 1976) pg. 592.
- , C. L. Kober, Passive geophysical prospection system based
upon the detection of the vertical electric field component of
telluric currents and method therefore
- Burrell et al., "Pulse Propagation in Lossy Media Using the Low
Frequency Window for Video Pulsed Radar Application", Proceedings
of the IEEE, Vol. 67, No. 7, July 1979, pgs. 981-990.
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Ailsa Allaby and Michael Allaby. Oxford University Press,
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National Academies Press, Commission on Physical Sciences,
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dem Erdmagnetismus". Leopold-Voss-Verlag, Leipzig und
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between telluric currents and the earth’s magnetic field",
Geophysics, 19, 281-289, 1954.
- 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.
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"Circuitry of the U.S.G.S. telluric profiler". U.S.
Geological Survey open-file report ; 87-332, Denver, Colo. : U.S.
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- Berdichevskiĭ, Mark Naumovich, "Elektricheskaya razvedka
metodom telluricheskikh tokov". Boston Spa, Yorkshire :
National Lending Library for Science and Technology, 1963. LCCN
92140338 (Tr., "Electrical surveying by means of telluric
currents"; Translation by J.E.S. Bradley)
- Hoover, Donald B., Pierce, H. A., and Merkel, D. C.,
"Telluric traverse and self potential data release in the
vicinity of the Pinson Mine, Humboldt County, Nevada". U.S.
Geological Survey open-file report; 86-341. U.S. Dept. of the
Interior, Geological Survey, 1986.
- " Electrical Conductivity : Models of the Crust and
Scientists engaged in the study of the Earth using electromagnetic
methods, principally the magnetotelluric technique
- 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