Pre-earthquake magnetic pulses

Abstract. A semiconductor model of rocks is shown to describe unipolar magnetic pulses, a phenomenon that has been observed prior to earthquakes. These pulses are suspected to be generated deep in the Earth's crust, in and around the hypocentral volume, days or even weeks before earthquakes. Their extremely long wavelength allows them to pass through kilometers of rock. Interestingly, when the sources of these pulses are triangulated, the locations coincide with the epicenters of future earthquakes. We couple a drift-diffusion semiconductor model to a magnetic field in order to describe the electromagnetic effects associated with electrical currents flowing within rocks. The resulting system of equations is solved numerically and it is seen that a volume of rock may act as a diode that produces transient currents when it switches bias. These unidirectional currents are expected to produce transient unipolar magnetic pulses similar in form, amplitude, and duration to those observed before earthquakes, and this suggests that the pulses could be the result of geophysical semiconductor processes.

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Pre-earthquake magnetic pulses

Natural Hazards and Earth System Sciences Discussions ◽

10.5194/nhessd-2-7367-2014 ◽

2014 ◽

Vol 2 (12) ◽

pp. 7367-7381 ◽

Cited By ~ 1

Author(s):

J. Scoville ◽

J. Heraud ◽

F. Freund

Keyword(s):

Magnetic Field ◽

Diffusion Model ◽

System Of Equations ◽

Drift Diffusion Model ◽

Transient Currents ◽

Drift Diffusion ◽

Electrical Currents ◽

Long Wavelength ◽

Electromagnetic Effects ◽

Pass Through

Abstract. A semiconductor model of rocks is shown to describe unipolar magnetic pulses, a phenomenon that has been observed prior to earthquakes. These pulses are generated deep in the Earth's crust, in and around the Hypocentral volume, days or even weeks before Earthquakes. They are observable at the surface because their extremely long wavelength allows them to pass through kilometers of rock. Interestingly, the source of these pulses may be triangulated to pinpoint locations where stresses are building deep within the crust. We couple a semiconductor drift-diffusion model to a magnetic field in order to describe the electromagnetic effects associated with electrical currents flowing within rocks. The resulting system of equations is solved numerically and it is seen that a volume of rock may act as a diode that produces transient currents when it switches bias. These unidirectional currents are expected to produce transient unipolar magnetic pulses similar in form, amplitude, and duration to those observed before earthquakes, and this suggests that the pulses could be the result of geophysical semiconductor processes.

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Magnetic effects due to earthquakes and underground explosions: a review

Annals of Geophysics ◽

10.4401/ag-3904 ◽

1997 ◽

Vol 40 (2) ◽

Author(s):

V. V. Surkov ◽

V. A. Pilipenko

Keyword(s):

Magnetic Induction ◽

Geomagnetic Field ◽

Seismic Waves ◽

Physical Nature ◽

Earth’S Crust ◽

Magnetic Effects ◽

Tsunami Detection ◽

Electromagnetic Effects ◽

Earth's Crust ◽

Theoretical Results

The physical nature of quasi-static and transient anomalies in the geomagnetic field induced by underground explosions or earthquakes is reviewed. New theoretical results obtained recently and so far little known to general circles of geophysicists are presented. The physical nature of residual magnetic and electrotelluric fields at the explosion point are considered. The seismic waves from explosions or distant earthquakes are suggested to be used as a tool for the preliminary probing of the Earth's crust sensitivity to various seismo-electromagnetic effects. The use of magnetic induction effects for tsunami detection and for crust sounding is outlined. The nature of ULF magnetic impulses related with earthquakes is discussed.

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D magnetic model of the Earth’s crust of the White Sea and adjacent territories

Arctic Ecology and Economy ◽

10.25283/2223-4594-2021-3-375-385 ◽

2021 ◽

Vol 11 (3) ◽

pp. 375-385

Author(s):

M.Y. Nilov ◽

◽

L.I. Bakunovich ◽

N.V. Sharov ◽

B.Z. Belashev ◽

...

Keyword(s):

Magnetic Field ◽

White Sea ◽

Sedimentary Cover ◽

Magnetic Anomalies ◽

Earth’S Crust ◽

The White Sea ◽

Spatial Frequencies ◽

Magnetic Model ◽

Earth's Crust ◽

The Relationship

An important task for the White Sea region, Russia’s second largest diamond-producing province, is the search for magmatic bodies overlapped by sedimentary cover via magnetometer survey. The models, linking local and magnetic anomalies with their sources, are essential for interpretation of search results. The aim of the study is to build a 3D magnetic model of the Earth’s crust for the White Sea region using aeromagnetic data and the modeling technologies of the Integro software package. The simulation is basing on a digital map of the pole-reduced anomalous magnetic field. The sources of magnetic anomalies are believed to be located in the Earth’s crust. The researchers obtained 3D distribution of the relative magnetic susceptibility of rocks by solving the inverse problem of magnetic prospecting. To separate the magnetic sources by spatial frequencies and depth, the model magnetic field was recalculated upward, as well as the TDR derivatives, which determine the lateral boundaries of the sources of positive magnetic field anomalies, were calculated. The researchers further analyzed 2D distributions of the magnetic sources of the model for vertical and horizontal sections with depths of 10, 15 and 20 km, thus proving the relationship between the surface and deep structures of the magnetic sources of the Earth’s crust in the region.

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