Robust Statistical Methods to Discriminate Extreme Events in Geoelectrical Precursory Signals: Implications with Earthquake Prediction

In this study, we propose a robuststatistical method to discern anomalous patternsin geoelectrical time series measured in a seismicarea of the Southern Apennine chain. First, a filteringprocedure to remove seasonal effects related tometeo-climatic fluctuations was carried out.Then, we selected an autoregressive model able todescribe the time fluctuations of geoelectricalsignals and propose a method to obtain an objectiveestimate of probability of occurrence for each extremeevent detected in the time series. Our applications inSouthern Italy allow us to hypothesize that theambiguity of short-term prediction is within thecomplicated dynamics of the physical processresponsible for electrical anomalies observed on theearth's surface.