A Geodetic Strain Rate and Tectonic Velocity Model for China

The conjoining and interfering influence of the Circum-Pacific zone and the Tethys-Himalayan zone make China a country of intense intracontinental seismicity. Here we provide three new quantitatively assessed products and use them to better constrain seismic hazards in China. First, we process similar to 2,700 Global Positioning System (GPS) data spanning 1996-2017 provided by the Crustal Movement Observation Network of China (CMONOC) network and the Nevada Geodetic Laboratory. To produce a robust tectonic velocity solution, we implement a data editing scheme to account for 8Mw >= 7 earthquakes to reduce the influence of transient phenomena. The solution is then rotated into a consistent reference frame with 10 other published velocity sources surrounding mainland China. Second, we calculate a new geodetic strain rate model using an optimal mesh grid definition of 0.4 degrees x0.4 degrees determined jointly by the Nyquist frequency method and checkerboard tests. We evaluate and validate the geodetic strain rate results from both a statistical (i.e., based on the Bayesian factor) and quantitative (i.e., based on the comparison with the 2-D analytical strain rate result) approaches. Third, we use our new geodetic strain rate model to estimate seismicity rates.