Post seismo-ionospheric perturbations linked to the Turkey earthquake of February 6, 2023 using GPS-TEC data

Seismo-ionospheric abnormalities are typically detected using total electron content (TEC) measurements taken from satellites. In this study, global positioning system (GPS) - TEC data from 3 sites in the seismic zone of the magnitude 7.8 Turkey earthquake (EQ) of February 6, 2023, were examined with the ultimate aim of detecting their possible link with the impending seismic event, to mitigate loss of lives and property. For the purpose of finding abnormal and differential TEC, a statistical approach was applied to daily TEC ten days pre- and ten days post the seismic event. The results showed that the investigation period days 1, 4, 8, and 9 showed enhancement in diurnal TEC, and that KABR and CSAR sites were the only sites that registered aberrant TEC. Results of the analysis, constrained by information from contemporaneously monitored geomagnetic indices of Kernnifzer digit (kp), disturbance storm time (Dst), and solar indices (sunspot number (SSN) and F10.7 cm), indicated post-seismic induced anomalies related to the earthquake on the 8th and 9th days after the event. The TEC differential data were notably high four days post-event. This led to the mapping of TEC indices on February 9 and 10, 2023, above the EQ epicenter to investigate anomalous coordinated universal time (UTC) hours correlating with the earthquake. The global ionospheric map GIM-TEC did not link the occurrence of anomalous ionospheric clouds over the epicenter to the seismic event. This work revealed post-seismo-ionospheric variations through GPS-TEC data concomitant to the M7.8 Turkey geo-quake of February 6, 2023, which served as a short-term earthquake indicator that may have mitigated the catastrophic loss of lives and properties from its numerous aftershocks. The perturbations on the 8th and 9th days post-event served as precursors to the M6.4 February 20th earthquake.