Strain and stress field in Taiwan oblique convergent system:
constraints from GPS observation and tectonic data
Shih-Chi Ho
Abstract
The island of Taiwan is a product of the oblique collision between the Luzon arc
and the Chinese continental margin. The deformations in Taiwan convergent system
have been largely studied based on a variety of geological and geophysical
observations. In this paper, we focuses on the stress and strain rate field of the Taiwan
area. We used the GPS survey data from 1990 to 1995 to calculate the strain field in
the Taiwan area. Notes that the data do not include the coseismic deformation related
to major earthquakes of Taiwan like Chi-Chi earthquake, and this may reflect the
major long-term tectonics of Taiwan. We then compare the strain rate field with the
stress information provided by studies of borehole breakouts and earthquake focal
mechanisms, and fault slip data. In the first approximation, the stress and strain rate
fields show spatial similarity. The orientation of principal shortening is generally
consistent with the compressive stress orientation that reflect the oblique collision
direction. In more detail, significant anomalies in the deformation pattern deserve
consideration in that they may reveal ongoing stress accumulation. Despite the
short-term variations related to the earthquake cycle, some major features of the strain
rate field highlight the long term tectonic behavior of the mountain belt at the
lithosphere scale.
Reference
Hu, J. C., Angelier, J., Yu, S. B., 1997, An interpretation of the active deformation of
southern Taiwan based on numerical simulation and GPS studies,
Tectonophysics, 274, 145-169
Yu, S. B., Chen, H. Y., Kao, L. C., 1997, Velocity field of GPS stations in the Taiwan
area, Tectonophysics, 274, 41-59