Investigation of ULF magnetic anomaly before moderate earthquakes
Ashok K. Sharma 1 3 Amol V. Patil 2 Rangnath N. Haridas 11 Space and Earth Sciences Laboratory, Department of Physics, Shivaji University, Kolhapur 416004, India.
2 Tatyasaheb Kore Institute of Engineering & Technology, Warananagar–416113, Maharashtra, India.
3 Corresponding author. Email: sharma_ashokkumar@yahoo.com
Exploration Geophysics 43(1) 36-46 https://doi.org/10.1071/EG10021
Submitted: 21 August 2010 Accepted: 19 October 2011 Published: 5 December 2011
Abstract
Electromagnetic anomalies covering a wide range of frequencies from ultra low frequency (ULF), very low frequency (VLF) up to very high frequency (VHF) have been observed before earthquakes. However, the ULF range emissions provide a greater source of information regarding the earthquake precursor. One of the main techniques of investigating such a precursor is by using a magnetic sensor. In this paper, we have carried out a study of spectral density (magnetic field intensity) and polarization ratio methods to extract earthquake precursory signatures of the ULF data for moderate earthquakes (magnitude Mb = 3.7–4.8), using a three-component induction coil magnetometer installed at Shivaji University, Kolhapur (16.40°N, 74.15°E), India. We have applied a Fast Fourier Transform (FFT) procedure to calculate the spectral density of the ULF time series. We have found enhancement in ULF magnetic field intensity 3 to 5 days before the main shock and this specific enhancement appeared ±3 h around the main shock time in the 1–5 Hz frequency range. We have examined ULF variations with polarization values and Kp index data. Magnetic field intensity of ULF data can give important information about earthquake preparation processes and it can be involved in the development of earthquake prediction methodology.
Key words: induction coil magnetometer, main shock time, seismo-electromagnetic emissions, short-term earthquake prediction, ULF (Ultra Low Frequency).
References
Bella, F., Biagi, P. F., Caputo, M., Cozzi, E., Della, M. G., Ermini, A., Plastino, W., and Sgrigna, V., 1998, Anomalies in different parameters related to the M = 3.9 Gran Sasso Earthquake (1992): Physics and Chemistry of the Earth, 23, 959–963| Anomalies in different parameters related to the M = 3.9 Gran Sasso Earthquake (1992):Crossref | GoogleScholarGoogle Scholar |
Brady, B. T., and Rowell, G. A., 1986, Laboratory investigation of the electrodynamics of rock fracture: Nature, 321, 488–492
| Laboratory investigation of the electrodynamics of rock fracture:Crossref | GoogleScholarGoogle Scholar |
Cress, G. O., Brady, B. T., and Rowell, G. A., 1987, Sources of electromagnetic radiation from fracture of rock samples in the laboratory: Geophysical Research Letters, 14, 331–334
| Sources of electromagnetic radiation from fracture of rock samples in the laboratory:Crossref | GoogleScholarGoogle Scholar |
Draganov, A. B., Inan, U. S., and Taranenko, Y. N., 1991, ULF magnetic signatures at the earth surface due to ground water flow: a possible precursor to earthquakes: Geophysical Research Letters, 18, 1127–1130
| ULF magnetic signatures at the earth surface due to ground water flow: a possible precursor to earthquakes:Crossref | GoogleScholarGoogle Scholar |
Fenoglio, M. A., Johnston, M. J. S., and Byerlee, J. D., 1995, Magnetic and electric fields associated with changes in high pore pressure in fault zones: application to the Loma Prieta ULF emissions: Journal of Geophysical Research, 100, 12951–12958
| Magnetic and electric fields associated with changes in high pore pressure in fault zones: application to the Loma Prieta ULF emissions:Crossref | GoogleScholarGoogle Scholar |
Freund, F., 2000, Time resolved study of charge generation and propagation in igneous rocks: Journal of Geophysical Research, 105, 11001–11019
| Time resolved study of charge generation and propagation in igneous rocks:Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3cXktVOgtro%3D&md5=83be3e1d7b3fd0d83e0eb3d24dc22212CAS |
Freund, F., 2002, Charge generation and propagation in rocks: Journal of Geodynamics, 33, 543–570
| Charge generation and propagation in rocks:Crossref | GoogleScholarGoogle Scholar |
Hattori, K., Akinaga, Y., Hayakawa, M., Yumoto, K., Nagao, T., and Uyeda, S., 2002, ULF magnetic anomaly preceding the 1997 Kagoshima earthquakes: Terra Scientific Publishing Company, Tokyo, 19–28.
Hayakawa, M., 1999, Atmospheric and ionospheric electromagnetic phenomenon associated with earthquakes: Terra Scientific Publishing Company, Tokyo, 996.
Hayakawa, M., and Fujinawa, Y., 1994, Electromagnetic phenomenon related to earthquake prediction: Terra Scientific Publishing Company, Tokyo, 677.
Hayakawa, M., and Hobara, Y., 2010, Current status of seismo-electromagnetics for short-term earthquake prediction: Geomatics: Geomatics, Natural Hazards and Risk, 1, 115–155
| Current status of seismo-electromagnetics for short-term earthquake prediction: Geomatics:Crossref | GoogleScholarGoogle Scholar |
Hayakawa, M., and Molchanov, O. A., 2002, Seismo electromagnetics: lithosphere-atmosphere-ionosphere coupling: Terra Scientific Publishing Company, Tokyo, 477.
Hayakawa, M., Kawate, R., Molchanov, O. A., and Yumoto, K., 1996, Results of ultra low-frequency magnetic field measurements during Guam earthquake of 8 August 1993: Geophysical Research Letters, 23, 241–244
| Results of ultra low-frequency magnetic field measurements during Guam earthquake of 8 August 1993:Crossref | GoogleScholarGoogle Scholar |
Hayakawa, M., Itoh, T., Hattori, K., and Yumoto, K., 2000, ULF electromagnetic precursors for an earthquake at Biak, Indonesia in 17 February 1996: Geophysical Research Letters, 27, 1531–1534
| ULF electromagnetic precursors for an earthquake at Biak, Indonesia in 17 February 1996:Crossref | GoogleScholarGoogle Scholar |
Hayakawa, M., Hattori, K., and Ohta, K., 2007, Monitoring of ULF geomagnetic variations associated with earthquakes: Sensors (Basel, Switzerland), 7, 1108–1122
| Monitoring of ULF geomagnetic variations associated with earthquakes:Crossref | GoogleScholarGoogle Scholar |
Kushwah, V., and Singh, B., 2004, Initial results of ultra low frequency magnetic field observations at Agra and their relation with seismic activities: Current Science, 87, 332–339
Kushwah, V., Singh, V., Singh, B., and Hayakawa, M., 2005, Ultralow frequency magnetic field anomalies observed at Agra and their relation to moderate seismic activities in Indian region: Journal of Atmospheric and Solar-Terrestrial Physics, 67, 992–1001
| Ultralow frequency magnetic field anomalies observed at Agra and their relation to moderate seismic activities in Indian region:Crossref | GoogleScholarGoogle Scholar |
Nagao, T., Enomoto, Y., Fujinawa, Y., Hata, M., Hayakawa, M., Huang, Q., Izutsu, J., Kushida, Y., Maeda, K., Oike, K., Uyeda, S., and Yoshino, T., 2002, Electromagnetic anomalies associated with 1995 Kobe earthquake: Journal of Geodynamics, 33, 401–411
| Electromagnetic anomalies associated with 1995 Kobe earthquake:Crossref | GoogleScholarGoogle Scholar |
Smirnova, N, Hayakawa, M, and Gotoh, K, 2004, Precursory behavior of fractal characteristics of the ULF electromagnetic fields in seismic active zones before strong earthquakes: Physics and Chemistry of the Earth, 29, 445–451
Tsarev, V. A., and Sasaki, H., 1999, Low frequency seismogenic electromagnetic radiation: how does it propagate in the earth’s crust and where can it be detected? in M. Hayakawa, ed., Atmospheric and ionospheric electromagnetic phenomena associated with earthquakes: Terra Scientific Publishing Company, Tokyo, 383–393.
Varotsos, P., and Alexopoulos, K., 1984, Physical properties of the variations of the electric field of the Earth preceding earthquakes I: Tectonophysics, 110, 93–98
Varotsos, P., Lazaridou, M., Eftaxias, K., Antonopoulos, G., Makris, J., and Kopanas, J., 1996, Short-term earthquake prediction in Greece by seismic electric signals, in S. J. Ligthhill, ed., A critical review of VAN: earthquake prediction from seismic electric signals: World Scientific Publishing Co., Singapore, 29–76.