The relationship between crustal deformation characteristics and strong earthquakes in western China revealed by GNSS

To clarify the relationship between GNSS (Global Navigation Satellite System) crustal deformation and the preparation of strong earthquakes in the western Chinese Mainland, a series of methods including velocity field, strain rate field, and strain parameter time series are adopted based on the GNSS observation data from the CMONOC (Crustal Movement Observation Network of China). The abnormal characteristics of crustal deformation movement before the M ≥ 5 earthquakes in the area since 1999 are studied. The corresponding variety of the crustal movement before earthquakes is discussed in combination with the seismogenic structure of earthquakes. The abnormalities of the GNSS velocity field, strain field, and strain parameter time series before earthquakes with different magnitudes are proposed. Finally, the anomaly criterion before medium-strong-large earthquakes in the western Chinese Mainland is proposed according to the GNSS and its combination with the characteristics of geological structure. The results can provide a basis for the forecasting of the trend and location of medium-strong-large earthquakes in the western Chinese Mainland.