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Petroleum Geo-Electrical Survey
Published in Muhammad Abdul Quddus, Petroleum Science and Technology, 2021
The origin of the telluric current and magnetic field is the ionosphere. The ionosphere is the upper portion of the earth’s atmosphere (90–500 km above sea level) containing charged (ionized) particles. The charged particles generate a magnetic field. The magnetic field starting from the ionosphere and reaching earth is known as the telluric magnetic field. The radiation from the sun and the earth’s rotation leads to variation in the telluric magnetic field. The variation of earth’s magnetic field also introduces telluric current in the earth. The variation of the telluric magnetic field induces an AC current of low frequency in the earth.
All About Wave Equations
Published in Bahman Zohuri, Patrick J. McDaniel, Electrical Brain Stimulation for the Treatment of Neurological Disorders, 2019
Bahman Zohuri, Patrick J. McDaniel
There is nothing particularly controversial about Longitudinal Waves (hereafter LW) in general as illustrated in Figure 2.11. They are a ubiquitous and well-acknowledged phenomenon in nature. Sound waves traveling through the atmosphere (or underwater) are longitudinal; as are plasma waves propagating through space also known as Birkeland currents. Longitudinal waves moving through the Earth’s interior are known as “Telluric currents.” They can all be thought of as pressure waves of sorts.
Discussion on the sea–land telluric current vector and its continuity during a geomagnetic storm based on coastal stations in China and Canada
Published in Geomatics, Natural Hazards and Risk, 2019
Xin Zhang, Qing Ye, Gaochuan Liu
GIC is a kind of induced currents, which is superimposed on the conductive current inside the earth to form the telluric current. In another word, GIC may lead to a change in the direction of telluric current if the magnetic storm is strong, and the baseline potential is low. The calculation results for the telluric current vectors during the two storms indicate that the telluric currents of the terrestrial stations almost point to inland. That means they flow from the high-potential area to low-potential areas. In particular, there are short-term directional changes at the XNY and HAA stations. The telluric current indirectly reflects both space geomagnetic disturbances and the electrical structure inside the earth (Lanzerotti et al. 1993; Shimizu and Utada 2004). Therefore, the reason for the change in current direction is that the observed value of geoelectric field is still very small (<10 mV/km). The current direction at XNY is repetitive due to its electrode instability. But, HAA station maintained a NE-trending current direction in 2015, which is consistent with the strike of the fault zone near the station site, and rotates northwest near the coast.