Tectonic effect for establishing a semi-dynamic datum in Southwest Taiwan

Abstract

To accommodate the effects of crustal deformation in the current national static geodetic datum (Taiwan Geodetic Datum 1997 (TWD97)) in SW Taiwan, 221 campaign-mode global positioning system (GPS) stations from 2002 to 2010 were used in this study to generate a surface horizontal velocity model for establishing a semi-dynamic datum in SW Taiwan. An interpolation method, Kriging, and a tectonic block model, DEFNODE, were used to construct the surface horizontal velocity model. Forty-four continuous GPS stations were used to examine the performance of the semi-dynamic datum through exterior validation. The average values of the residual errors obtained using the Kriging method for the north and east components are ±1.9 and ±2.2 mm/year, respectively, whereas those obtained using the block model are ±2.0 and ±2.9 mm/year, respectively. The distribution of residuals greater than 5 mm/year for both models generally corresponds to a high strain rate area derived using the horizontal velocity field. In addition, these residuals may result from deep-seated landslide and active folding or mud diapir in a mudstone area. Similar exterior checking results obtained using the Kriging interpolation method and block model for SW Taiwan indicate a high station density and a relatively satisfactory station spatial coverage. However, the block model is superior to the Kriging method due to the consideration of characteristics of the geological structure in the block model. In addition, result from traditional coordinate transformation was used to compare with the semi-dynamic datum. The results indicate that a semi-dynamic datum is a feasible solution for maintaining the accuracy of TWD97 at an appropriate level over time in Taiwan.

3D Vs ambient noise tomography of the 2016 Mw 6.4 Meinong Earthquake source region in Taiwan

“…This could indicate that the shallow structure plays an important role for the coseismic displacement. GPS and leveling data from 2000 -2010 have shown a similar uplift pattern as the coseismic pattern from the InSAR results and the uplift rate from GPS and leveling data can be up to 20 mm yr -1 in this region (Ching and Chen 2015). Ching and Chen (2015) and Huang et al (2016) suggested that the deformation pattern could be controlled by high pore fluid pressure within the Pls, Pec, and Pgtk Formations and a relic onshore mud diapir beneath those formations.…”

“…GPS and leveling data from 2000 -2010 have shown a similar uplift pattern as the coseismic pattern from the InSAR results and the uplift rate from GPS and leveling data can be up to 20 mm yr -1 in this region (Ching and Chen 2015). Ching and Chen (2015) and Huang et al (2016) suggested that the deformation pattern could be controlled by high pore fluid pressure within the Pls, Pec, and Pgtk Formations and a relic onshore mud diapir beneath those formations. Huang et al (2016) argued that the high pore fluid pressure region plays an important role in the dynamic stress changes that trigger this coseismic deformration.…”

The Implementation of Modern Geocentric Datum: A Review

“…Thus, the authors could assume Brunei realizing a semidynamic datum due to the elements of estimating a horizontal velocities field. This estimation is significance towards semidynamic datum establishment to maintain the coordinate accuracy of sites (Ching and Chen, 2016).…”

HV-LSC-ex$$^2$$: velocity field interpolation using extended least-squares collocation

“…In contrast, Kriging has been used more widely (e.g. Kierulf et al 2013;Bogusz et al 2014;Ching and Chen 2015;Fuhrmann et al 2015;Béjar-Pizarro et al 2016;Robin et al 2020) and comparison to other interpolation techniques has shown its advantages (e.g. Bogusz et al 2014).…”