Scrutinizing and rooting the multiple anomalies of Nepal earthquake sequence in 2015 with the deviation–time–space criterion and homologous lithosphere–coversphere–atmosphere–ionosphere coupling physics

Abstract

The continuous increasing of Earth observations benefits geosciences and seismicity study but increases greatly the difficulties in understanding and discriminating multiple source data. Although the lithosphere–coversphere–atmosphere-ionosphere (LCAI) coupling paradigm and the deviation–time–space (DTS) criterion were presented for better searching for and understanding the potential seismic anomalies from multiple observations, the strict consistency of spatiotemporal characteristics and homologous physics of multiple-parameter seismic anomalies has not been investigated sufficiently. With the 2015 Nepal earthquake sequence being a typical case, the reported multi-parameter anomalies were systematically reviewed, and their space–time characteristics were summarized thoroughly in this study. Numerical simulation with refined geological structures in three-dimensional space revealed the inhomogeneous crustal stress field alteration (CSFA) along the faults and around the hypocenters of the 2015 Nepal earthquake sequence, which is expected to be the root of the seismic anomalies. The stress-activated positive charge carriers would have given rise to different responses near the ground surface (coversphere), including the microwave dielectric reduction, the additional infrared radiation, and the atmospheric ionization, which subsequently affected the physical properties of the atmosphere and the ionosphere and resulted in abnormal phenomena therein. Based on the DTS criterion and LCAI coupling paradigm, the seismic anomalies of the 2015 Nepal earthquakes were scrutinized strictly, and the retained anomalies were rooted carefully to the regional CSFA as well as its local blocking. Therefore, an integrated LCAI coupling framework with strict space–time correspondence and homologous physics in CSFA was proposed for the 2015 Nepal earthquake sequence. This research provides a definite philosophy as well as a practical solution for scrutinizing the rootable seismic anomalies from multi-parameter observations of earthquakes, which is of scientific meanings for searching earthquake precursors and reaching earthquake prediction.