The LF radio anomaly observed before the Mw = 6.5 earthquake in Crete on October 12, 2013

Publication date: Available online 20 October 2015 Source:Physics and Chemistry of the Earth, Parts A/B/C Author(s): Tommaso Maggipinto, Pier Francesco Biagi, Roberto Colella, Luigi Schiavulli, Teresa Ligonzo, Anita Ermini, Giovanni Martinelli, Iren Moldovan, Hugo Silva, Michael Contadakis, Christos Skeberis, Zaharias Zaharis, Emmanuel Scordilis, Konstantinos Katzis, Aydın Buyuksarac, Sebastiano D'Amico On October 12, 2013, an earthquake with Mw = 6.5 occurred in the southern Hellenic Arc, approximately 20 km off the west coast of Crete. The main shock, the focal depth of which is on the order of 40 km, was followed by aftershocks felt in the nearby cities and villages, although the aftershock sequence was poor. The epicentre was located at approximately 60 km from a radio receiver in Crete (CRE), which belongs to the European VLF/LF Radio Network. Several days before the earthquake, a clear disturbance occurred in one of the ten radio signals that the CRE receiver sampled. The disturbance, which can be considered an anomaly, appeared in the 216 kHz radio signal radiated by the Radio Monte Carlo (MCO) transmitter. The radio path MCO-CRE crossed directly over the epicentre area of the aforementioned earthquake. In this work, we present a detailed analysis of the MCO signal anomaly using spectral tools. We also investigate the behaviour of other radio signals sampled by the CRE receiver and consider other possible causes of disturbance...
Source: Physics and Chemistry of the Earth, Parts ABC - Category: Science Source Type: research