Singular spectral analysis applied to magnetotelluric time series collected at Medea Geomagnetic Observatory (Algeria)—an attempt to discriminate earthquake-related electromagnetic signal

A magnetotelluric (MT) station was installed in the northern part of Algeria in December 2014 with the aim of investigating any electromagnetic phenomena related to crustal activities. Significant changes in the five channels of the MT signal amplitude were observed during a sequence of minor to light earthquakes that occurred in the vicinity of the MT station. We applied the singular spectral analysis (SSA) method to the recorded magnetotelluric time series in order to discriminate the co-seismic electromagnetic signals. In particular, we investigated the reconstructed components extracted from the telluric and magnetic field components. Based on the obtained results, the co-seismic electric signal can be found in the third reconstructed component for the two electric field components. On the other hand, the three magnetic components do not present the same results after the application of the SSA technique, where the co-seismic magnetic signal can be found in different reconstructed components. In this work, the adopted analysis method has shown its ability to clearly detect co-seismic electromagnetic signals in the magnetotelluric time series. The primary goal of this work is to implement an effective algorithm for detecting clearly co-seismic electromagnetic signals.