Ionospheric anomalies associated with the <i>M</i><sub>w</sub> 7.3 Iran–Iraq border earthquake and a moderate magnetic storm

Abstract

Abstract. The analysis of the unexpected ionospheric phases before large earthquakes is one of the cutting-edge issues in earthquake prediction studies. In this study, the total electron content (TEC) data from seven International GNSS Service (IGS) stations and the global ionosphere maps (GIMs) were used. Short-time Fourier transform (STFT) and a running median process were applied to the TEC time series to detect abnormalities before the Mw 7.3 Iran–Iraq border earthquake on 12 November 2017. The analyses showed positive anomalies 8–9 d before the earthquake and some positive and negative anomalies 1–6 d before the earthquake. These anomalies were cross-checked using the Kp, Dst, F10.7, Bz component of the interplanetary magnetic field (IMF Bz), electric field (Ey), and plasma speed (VSW) space weather indices. The results showed that the anomalies 1–6 d before the earthquake were caused by a moderate magnetic storm. Moreover, the positive anomalies 8–9 d before the earthquake were likely related to the Iran–Iraq border earthquake due to quiet space weather, local dispersion, and the proximity to the epicenter.

Discriminating the Multi-Frequency Microwave Brightness Temperature Anomalies Relating to 2017 Mw 7.3 Sarpol Zahab (Iran-Iraq Border) Earthquake

“…Meanwhile, these up-swelling carbonaceous gases would had changed the composition of the atmosphere near ground surface accompanied by greenhouse effect, air-water condensation and aerosol generation, thus AOT and the water vapor behaved anomaly from 17 to 9 days and 6 to 4 days preceding the earthquake, respectively (Akhoondzadeh et al, 2019). The air ionization from possible radon gas emission was also supposed, and it could had ultimately disturbed the TEC in the ionosphere from 11 to 8 days preceding the earthquake (Akhoondzadeh et al, 2019;Tariq et al, 2019;Senturk et al, 2020). Supplementary Figure S3 shows the temporal distribution of seismic precursor anomalies.…”

Spatial and Temporal Analysis of Climatic Precursors before Major Earthquakes in Iran (2011–2021)

“…Therefore, the lithosphere-atmosphere-ionosphere coupling (LAIC) model, developed by Pulinets et al ([17,22]), demonstrated the existence of geophysical anomalies prior to major earthquakes. However, there is still no consensus about the physical processes linking earthquake precursors [32]. Two types of physical processes were proposed to explain these linkages, including the release of radon from the ground (e.g., [15,62]) and the stress activation of the positive-hole charge carriers within the hypocentral volume and the field ionization of the air at the ground-to-air interface [8,9].…”