The coupling processes among the lithosphere, atmosphere, and ionosphere (LAI) during the earthquake preparation phase are still an open scientific debate. Comprehensive LAI coupling effects around the 2022 Ms6.8 Luding earthquake in China are investigated with a multi-parameter and multi-layer approach, including the b-value, revised accelerated moment release, Earth resistivity, ELF magnetic field emissions, atmospheric electric field, surface temperature, foF2 from ionosonde, GNSS TEC, Ne and magnetic field from CSES and Swarm satellites, and energetic electrons from CSES and NOAA satellites. It is found that the anomalies start from the lithospheric parameters as Earth resistivity and b-values 1–2 years before to reflect the local stress loading in the seismic region, then the ionospheric and atmospheric disturbances occur and accelerate −50 days before and −15 days before, and finally the electrons precipitate a few days before. The simultaneous perturbations in LAI illustrate the thermodynamic coupling channel, such as on 24 August, −12 days before. Meanwhile, the abundant developed ionospheric anomalies without atmospheric disturbances demonstrate the electromagnetic coupling way from the lithosphere to the ionosphere directly. Finally, the results demonstrate a two-way model of LAIC: one way is characterized by a slow chain of processes, of thermodynamic nature, starting from the ground and proceeding to the above atmosphere and ionosphere, showing an exponential trend in the cumulative number of anomalies; the second way is characterized by oscillating electromagnetic coupling between the lithosphere and ionosphere, showing intermittent fluctuations in the corresponding cumulative number of anomalies.

Anomalous ionospheric disturbances have been observed as potential precursors to earthquakes. This study utilized data from the CSES satellite to investigate anomalies in the ULF band ionospheric electric field and electron density preceding earthquakes with magnitudes of Ms ≥ 6.0 in China and neighboring regions from 2019 to 2021. Comparative analysis with a randomly generated earthquake catalog indicated that these anomalies were spatially concentrated over the epicenter and temporally clustered on specific dates prior to the events. To assess the global relevance of these findings, the analysis was extended to earthquakes with Ms ≥ 7.0 worldwide during the same period, revealing consistent spatiotemporal patterns of ionospheric anomalies in both regional and global datasets. Furthermore, by combining the two earthquake catalogs and classifying events into oceanic and continental categories, additional statistical analyses were conducted to identify distinct ionospheric disturbance patterns associated with these different tectonic environments. These results provide a solid foundation for future research aimed at identifying and extracting ionospheric anomalies as potential pre-earthquake indicators.

To explore the spatiotemporal evolution characteristics of pre-earthquake GPS TEC anomalies and their correlation with seismic activities, a statistical analysis was performed on pre-earthquake ionospheric GPS TEC anomalies associated with Ms ≥ 6.0 earthquakes in Mainland China from 2012 to 2022 using GPS TEC observational data. Two statistical metrics were adopted, namely average anomaly frequency and anomaly earthquake percentage. Classified statistical analyses were carried out from the perspectives of anomaly polarity, earthquake magnitude, focal depth, and different azimuths of the epicenter to systematically investigate the evolutionary characteristics of TEC anomalies from 30 days pre-earthquake to the earthquake day. The results show that the two core statistical indicators of pre-earthquake TEC anomalies present a significant increasing trend around the 25th, 15th, and 5th days before the earthquake and on the earthquake day. Moreover, the values of the two metrics corresponding to positive pre-earthquake TEC anomalies were higher than those corresponding to negative anomalies. Specifically, the values of the two metrics for pre-earthquake TEC anomalies of strong earthquakes with 6.8–7.6 were higher than those for 6.0–6.8 earthquakes. The spatial distribution of pre-earthquake TEC anomalies is characterized by inhomogeneity and time-dependent characteristics. Compared with earthquakes at a focal depth of 0–10 km, earthquakes at a focal depth of 10–20 km show more significant pre-earthquake TEC anomaly signals. Perturbation characteristics of pre-earthquake ionospheric GPS TEC were statistically analyzed, providing a reference for further elucidating the seismo-ionospheric coupling mechanism and identifying ionospheric precursors of earthquakes.

Due to the significant earthquake-related perturbations observed in the ionosphere by ground-based stations and space-borne satellites, scientists have increasingly focused on the studying the possible coupling mechanism among lithosphere, atmosphere and ionosphere. In this work, we contribute to this research, analyzing the phase of preparation of the 2022 Ms6.8 Luding (China) earthquake with a multi-parameter and multi-level approach from ground and satellite data taken in lithosphere, atmosphere and ionosphere, including the b value, earth resistivity, ELF magnetic field emissions, atmospheric electric field, surface temperature, foF2 from Ionosonde, GNSS TEC, magnetic field and electron density from CSES and Swarm satellites, etc. The results are encouraging confirming a chain of processes starting from ground and proceeding to the above atmosphere and ionosphere.

To verify the lithosphere-atmosphere-ionosphere coupling processes around strong earthquakes, a multi-parameter and multi-level approach from ground and satellite data have been paid more and more attention in recent researches. Taking Wushi Ms7.1 earthquake on 22 January 2024 as an example, multi parameters were included in the study, such as the earth resistivity, the geomagnetic field and geoelectric field in lithosphere, surface temperature and outgoing longwave radiation in atmosphere, while foF2 from Ionosonde, GNSS TEC, magnetic field and electron density, energetic particles from electromagnetic satellites for ionosphere, etc.. The results are encouraging confirming a chain of processes starting from ground and proceeding to the above atmosphere and ionosphere. The direct and indirect connection among multi layers and different parameters were discussed to build the energy preparation, developing and coupling processes for Wushi earthquake.