Browsing by Author "Rui, X."
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- A Geodetic Strain Rate and Tectonic Velocity Model for ChinaRui, X.; Stamps, D. Sarah (2019-03)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.
- Present-day kinematics of the eastern Tibetan Plateau and Sichuan Basin: Implications for lower crustal rheologyRui, X.; Stamps, D. Sarah (AGU, 2016-05-14)The Sichuan Province comprises the cratonic Sichuan Basin and the eastern Tibetan Plateau separated by the recently activated Longmen Shan fault zone, thus providing a natural laboratory to study interseismic and postseismic processes. In this work we compute a new regional geodetic velocity solution from most of the continuous Global Navigation Satellite Systems (GNSS)/GPS data available in the Sichuan Province that we assess for transient postseismic deformation. For 11 continuous sites in close proximity to the Wenchuan 2008 event epicenter that were operational during the Wenchuan event we find an average short-term relaxation time of 11 days with maximum amplitude of 6.6mm for the postseismic transient and no resolvable long-term transient. Using tests for block rigidity guided by previous kinematic studies we elucidate a longer-term transient in GNSS/GPS observations collected after the Wenchuan event that spans an extensive region of the eastern Tibetan Plateau. We correct for transients, produce an updated secular velocity field, and revise the kinematics of the region using elastic block modeling. Our results indicate that predicted slip rates are in good agreement with both geological and GNSS/GPS velocity profile-derived results, and we resolve two independent blocks with the expanded GNSS/GPS data set. Our constraints on the spatial extent of long-term postseismic deformation support models of ductile lower crust in the eastern margin of the Tibetan Plateau.