Spectral analysis of possible SES anomalies observed during aftershocks of the 2023 Kahramanmaraş Earthquakes

Abstract

Seismic Electric Signal (SES) refers to pre-earthquake geoelectric anomalies that may serve as precursors to seismic events. The detection and analysis of SES variations are crucial for short-term earthquake forecast. This study examines possible geoelectric changes observed before the aftershocks following the major earthquakes of February 6, 2023, in the Kahramanmaraş region, located at the southwestern end of the Eastern Anatolian Fault Zone (EAFZ). Geoelectric variations were recorded at GEO_MUK station (37.1738°N, 38.9932°E) during the 30-day period after the main earthquake. The Fast Fourier Transform (FFT) was used to analyze the time series data, revealing potential anomalous frequency components on the days surrounding the earthquakes. Additionally, the Welch Method was applied to determine the power density of these frequencies before and after the seismic events. To assess the influence of geomagnetic activity, the Kp storm index was used to identify active and quiet space weather conditions. The results suggest that the geoelectric variations observed during sequential aftershocks may be short-term indicators of potential earthquake precursors. While these findings highlight the need for further investigation, they do not provide conclusive evidence that SES anomalies are definitive earthquake precursors. The study emphasizes the importance of continued research into the generation and transmission of SES signals, as well as their potential role in earthquake forecasting.