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38 - Electromagnetic fields generated by earthquakes

January 1, 2002

Independent knowledge of the physical processes that occur with seismic events can be obtained from observations of electric and magnetic fields generated by these complex processes. During the past few decades, we have seen a remarkable increase in the quality and quantity of electromagnetic (EM) data recorded before and during earthquakes and volcanic eruptions. This paper describes the most significant recent data and the implications these data have for different generating mechanisms. We note that, despite several decades of relatively high quality monitoring, clear demonstration of the existence of precursory EM signals has not been achieved, although causal relations between coseismic magnetic field changes and earthquake stress drops are no longer in question. This paper extends discussions of tectonomagnetism and tectonoelectricity, over the various parts of the electromagnetic spectrum from radio frequencies (RF) to submicrohertz frequencies, that are covered in Johnston (1989, 1997), Park et al. (1993), Park (1996) special journal issues (Johnston and Parrot, 1989, 1998; Parrot and Johnston, 1993), and books (Hayakawa and Fujinawa, 1994).

Publication Year 2002
Title 38 - Electromagnetic fields generated by earthquakes
DOI 10.1016/S0074-6142(02)80241-8
Authors M.J.S. Johnston
Publication Type Article
Publication Subtype Journal Article
Series Title International Geophysics
Index ID 70243104
Record Source USGS Publications Warehouse