Seismo-electromagnetics
Encyclopedia
Seismo-electromagnetics is the study of electromagnetic
phenomena associated with seismic activity such as earthquake
s and volcano
s, and also the use of electromagnetic methods in seismology
such as magnetotellurics
. Links between the electromagnetic fields in the lithosphere
and those in the atmosphere
and ionosphere
are also studied. Earthquake prediction
is one of the aims of this area of research.
Electromagnetism
Electromagnetism is one of the four fundamental interactions in nature. The other three are the strong interaction, the weak interaction and gravitation...
phenomena associated with seismic activity such as earthquake
Earthquake
An earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves. The seismicity, seismism or seismic activity of an area refers to the frequency, type and size of earthquakes experienced over a period of time...
s and volcano
Volcano
2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...
s, and also the use of electromagnetic methods in seismology
Seismology
Seismology is the scientific study of earthquakes and the propagation of elastic waves through the Earth or through other planet-like bodies. The field also includes studies of earthquake effects, such as tsunamis as well as diverse seismic sources such as volcanic, tectonic, oceanic,...
such as magnetotellurics
Magnetotellurics
Magnetotellurics is an electromagnetic geophysical method of imaging the earth's subsurface by measuring natural variations of electrical and magnetic fields at the Earth's surface. Investigation depth ranges from 300m below ground by recording higher frequencies down to 10,000m or deeper with...
. Links between the electromagnetic fields in the lithosphere
Lithosphere
The lithosphere is the rigid outermost shell of a rocky planet. On Earth, it comprises the crust and the portion of the upper mantle that behaves elastically on time scales of thousands of years or greater.- Earth's lithosphere :...
and those in the atmosphere
Atmosphere
An atmosphere is a layer of gases that may surround a material body of sufficient mass, and that is held in place by the gravity of the body. An atmosphere may be retained for a longer duration, if the gravity is high and the atmosphere's temperature is low...
and ionosphere
Ionosphere
The ionosphere is a part of the upper atmosphere, comprising portions of the mesosphere, thermosphere and exosphere, distinguished because it is ionized by solar radiation. It plays an important part in atmospheric electricity and forms the inner edge of the magnetosphere...
are also studied. Earthquake prediction
Earthquake prediction
An earthquake prediction is a prediction that an earthquake of a specific magnitude will occur in a particular place at a particular time . Despite considerable research efforts by seismologists, scientifically reproducible predictions cannot yet be made to a specific day or month...
is one of the aims of this area of research.
See also
- Electrical resistivity tomographyElectrical resistivity tomographyElectrical resistivity tomography or electrical resistivity imaging is a geophysical technique for imaging sub-surface structures from electrical measurements made at the surface, or by electrodes in one or more boreholes. It is closely related to the medical imaging technique electrical...
- Induced polarizationInduced polarizationInduced polarization is a geophysical imaging technique used to identify subsurface materials, such as ore. The method is similar to electrical resistivity tomography, in that an electric current is induced into the subsurface through two electrodes, and voltage is monitored through two other...
- Seismoelectrical MethodSeismoelectrical MethodThe seismoelectrical method is based on the generation of electromagnetic fields in soils and rocks by seismic waves...
- MagnetometerMagnetometerA magnetometer is a measuring instrument used to measure the strength or direction of a magnetic field either produced in the laboratory or existing in nature...
- Telluric currentTelluric currentA telluric current , or Earth current, 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...
- VAN methodVAN methodThe VAN method is a controversial method for earthquake prediction based on the assumption that minerals under mechanical stress emit characteristic electrical signals. The name of the method derives from the surname initials of each of its inventors, Greek physicists Panayotis Varotsos, Caesar...
Further reading
- Monitoring of ULF (ultra-low-frequency) Geomagnetic Variations Associated with Earthquakes, Masashi Hayakawa, Katsumi Hattori and Kenji Ohta, Sensors 2007, 7, 1108–1122
- Pre-earthquake ionospheric anomalies registered by continuous GPS TEC measurements, J. Y. Liu, Y. J. Chuo, S. J. Shan, Y. B. Tsai, Y. I. Chen, S. A. Pulinets, and S. B. Yu, Annales Geophysicae (2004) 22: 1585–1593