Search of earthquake precursors basing on FRaSH method for identification measurements of seismographic records

Abstract

This work shows the possibility of search of timely earthquake precursors basing on the FRaSH method for identification measurements of the shape of instantaneous values distribution and characteristic frequency from seismographic record. It was found that during an earthquake there can be registered extreme sudden changes in the shape and characteristic frequency when scanning the seismographic record. However, in the time before the earthquake there can be seen smaller in value but still sudden changes of the shape and the characteristic frequency. These facts are used as timely precursors to predict earthquakes. The most suitable threshold value of identification variables that establish the timely short-term earthquake precursor and the corresponding prediction interval were determined. There was created a device that measures statistical variables, shape and characteristic frequency of the seismographic record, as well as searches for possible earthquake precursors. Besides there was elaborated a new method of determination of earthquake precursors based on sequential comparison of identification variables of shape and characteristic frequency to threshold values while getting closer to the time of earthquake.