The correlation study between EIA north crest in the south Asia region and strong earthquakes.

Paying attention to the relationship between EIA signatures and earthquakes can be useful to further understand the earthquake anomalies and seismo-ionospheric coupling mechanism. Based on the GIM TEC data, the EIA north crest signature in the south Asia region was investigated for 92 M ≥ 6.0 earthquakes from 1999 to 2022. A running mean method was utilized to extract the anomalies potentially associated with earthquakes. It was found that before the strong earthquakes, the EIA north crest significantly moves equatorward, and the formation time of the crest appears earlier than that in normal days. The TEC strength of EIA north crest can both increase or decrease prior to earthquakes. The results in this study further imply that the abnormal electric field formed around the epicenter is potential the main channel of Lithosphere-Atmosphere-Ionosphere Coupling (LAIC) mechanisms during the earthquake preparation period. [ABSTRACT FROM AUTHOR]