Reconciling High-resolution Strain Rate of Continental China from GNSS
Data with the Spherical Spline Interpolation
Abstract
In this work, we propose a new generation of high-resolution strain rate
model of present-day continental China from up-to-date GNSS observation
data of 3571 stations. To reconcile the sparsely distributed GNSS
(Global Navigation Satellite System) velocity data into an integrated
vastly regional spherical coordinate frame, a novel interpolation
method, namely the spherical spline method, is introduced as well. It
can simultaneously calculate the strain rate with an ideal order of
continuity while preserving the discontinuity from tectonically active
major fault zones or deforming blocks. We take advantage of a set of
inspection standards to assess the validity and resolution of our
proposed model. The spherical spline method is deliberately examined and
justified to fit the GNSS velocity data to illustrate inspection
standards. Moreover, we construct a spherical harmony model for the
resolution test. By the test criteria, the spherical spline method can
reproduce the velocity and strain rate field at substantial order,
suggesting that our method has high applicability and resolution in
estimating strain rate in active tectonic regions or even global models.
Finally, using the spherical spline method, we used measured GNSS
velocity data to calculate the strain rate field in continental China.
We also analyze the correlation between the seismic mechanism and the
strain rate field of earthquakes, exhibiting that our proposed
high-resolution strain rate model has great potential in explaining the
deformation or evolution models of continental China.