Analysis of Potential Precursory Pattern at Earth Surface and the Above Atmosphere and Ionosphere Preceding Two Mw ≥ 7 Earthquakes in Mexico in 2020–2021. Issue 10 (10th October 2022)

• Record Type: Journal Article
• Authors: Xu, Xitong; Chen, Shengbo; Zhang, Sen; Dai, Rui
• Is Part Of: Earth and space science. Volume 9:Issue 10(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-10-10
• Subjects: seismic thermal anomaly -- TEC -- Swarm satellite -- lithosphere‐atmosphere‐ionosphere coupling -- earthquake precursory pattern; Space sciences -- Periodicals; Geophysics -- Periodicals; 500.5
• DOI: 10.1029/2022EA002267
• Languages: English
• ISSNs: 2333-5084

Abstract

Abstract: Comprehensive analyses of seismic precursory characteristics may provide evidence for the possible mechanisms of lithosphere‐atmosphere‐ionosphere coupling (LAIC). The integrated monitoring data from space and ground measurements makes it possible to reveal the potential earthquake precursory pattern obeying LAIC. In this paper, we study seismic precursors from air temperature data of the National Center for Environmental Prediction (NCEP), Global Navigation Satellite System (GNSS) based Total Electron Content (TEC) and electron density retrieved from Swarm satellite (Alpha) data in two Mw ≥ $\ge $ 7.0 earthquakes in Mexico in 2020–2021. We find seismic thermal anomalies can be identified from temperature variation in the lithosphere and atmosphere by improved tidal force fluctuant analysis (TFFA). The spatial‐temporal evolution of seismic thermal anomalies is significantly different from that of non‐seismic thermal anomalies. In addition, synergistic observations of the Swarm Alpha satellite and GNSS stations can provide more comprehensive information about perturbations in the ionosphere. The results show that anomalies originate along fault lineaments near the epicenter, leading to air pressure gradient and ionization process in the atmosphere, followed by ionospheric perturbations. Furthermore, composite anomalies of LAIC first appear around a month before earthquakes and tend to recur several times over earthquake preparation phases. Our study provides more evidence for understanding the characteristics of earthquake precursors. Plain Language Summary: The physical processes of earthquake preparation have triggered plenty of scientific interest and discussion. The information and energy can be transported from underground to the lithosphere, atmosphere, and ionosphere, in the form of various precursors before earthquakes. However, previous studies reported the inconsistent occurrence time of observed precursors in the lithosphere, atmosphere, and ionosphere. It is necessary to explore the earthquake precursory pattern to integrate different types of anomalies and tease out their temporal relationship. We apply tidal force fluctuant analysis to anomaly detection of atmospheric and surface temperature based on National Center for Environmental Prediction reanalysis data, and Swarm Alpha satellite data and GNSS stations data are used to detect ionospheric perturbations. The results from two earthquakes in Mexico, Mw = 7.4 earthquake in 2020 and Mw = 7.0 earthquake in 2021, show that precursors follow the time rule from the lithosphere to the atmosphere and then to the ionosphere. Also, earthquake precursors appear around a month before earthquakes and have repeatability. This pattern could provide an important advance for earthquake prediction from multi‐source data. Key Points: Spatial‐temporal evolution of seismic thermal anomalies in lithosphere and atmosphere is investigated based on the variation of daily tidal force potential The temporal rule of anomalous transmission supports the coupling of lithosphere‐atmosphere‐ionosphere The earthquake precursory pattern obeying lithosphere‐atmosphere‐ionosphere coupling is explored