New radio-seismic indicator for ELF seismic precursors detectability

Abstract

This work considers the effectiveness of earthquakes (EQs) radio precursors mainly in the Extremely Low Frequency (ELF) range and below, and carries out an analysis based on a comprehensive set of EQ events documented in past publications and provided by the Opera 2015 project (six stations located in Italy). A new Radio-Seismic Indicator (RSI) is proposed, with the magnitude-distance relationship physically justified by path-loss expressions of the transverse magnetic mode. Classification performances of past and proposed RSIs are assessed calculating confusion matrices and on those the balanced accuracy and Matthews’ coefficient: the RSI performs significantly better reducing fall-outs and increasing precision for both classes, positive and negative precursors. Performance improvement is inherently limited by the overlap of the classes.