Short-term earthquake prediction in Kamchatka using low-frequency magnetic fields

This paper is devoted to a method of short-term earthquake (EQ) prediction in Kamchatka, Russia. Properties of low-frequency magnetic fields are the basics of the method, and we used two seismo-electromagnetic phenomena in the EQ prediction: 1. seismo-ionospheric depression in the frequency range of 0.01–0.1 Hz (ULF depression), 2. seismo-atmospheric radiation in the frequency range of 1–30 Hz (ULF/ELF radiation). It is now generally accepted that gas eruption before an EQ causes these ULF/ELF phenomena. We propose a hypothesis that gas emanates from the area in the bottom of Kuril–Kamchatka or Aleutian trenches closest to the epicenter of a forthcoming EQ. The three parameters of an EQ are (i) when (time), (ii) where (position) a next EQ is coming with (iii) how big (magnitude) in the short-term EQ prediction. Position of the source of atmospheric radiation gives an estimate of the epicenter location. Then, we estimate the local magnitude in consequence of its statistical dependence on ULF depression and epicenter distance. Date of a coming EQ is determined by the statistical dependence of delays of EQs relative to the dates of their precursors. The result of application of this method to real magnetic field data is illustrated by official prediction processes during a period of March–May 2016. Limits and possible errors of the method as well as methods to enhance the reliability of the prediction are discussed.