Co-seismic deformation of the 2017 M_s 7.0 Jiuzhaigou Earthquake observed with GaoFen-3 interferometry

ABSTRACT

The first application of GaoFen-3 synthetic aperture radar (SAR) interferometry to monitoring co-seismic deformation of an earthquake is presented in this paper. First, two GaoFen-3 SAR images spanning the 2017 surface-wave magnitude ($M_{\mathrm{s}}$) 7.0 Jiuzhaigou earthquake were mosaicked, coregistered and processed into an interferogram with visible fringes. After the removal of severe orbital errors and unwrapping, the co-seismic deformation field is obtained. Finally, the fault parameters and slip distribution are determined based on the deformation field. To evaluate the performance of GaoFen-3 in this case, the interferogram, co-seismic deformation field, derived fault parameters and slip distribution are compared with those derived from Radarsat-2, Sentinel-1A and Advanced Land Observing Satellite-2 (ALOS-2) Phased Array type L-band Synthetic Aperture Radar-2 (PALSAR-2). The comparisons between the deformation field obtained from GaoFen-3 and those obtained from Radarsat-2 and Sentinel-1A show Pearson’s correlation coefficient ($r$) values $>$ 90%, demonstrating that GaoFen-3 interferometry can measure the co-seismic deformation effectively. The resultant slip model obtained by GaoFen-3 interferometric measurements shows a simple, elliptical pattern of slip, reaching a maximum of approximately 1 m at depths of 10–13 km. The rake angle is almost $0^{\circ }$, which suggests left-lateral strike-slip motion, consistent with previous studies.

Acknowledgements

We would like to thank the National Satellite Ocean Application Service for providing GaoFen-3 data, the Canadian Space Agency (CSA) for providing RADARSAT-2 data, the European Space Agency (ESA) for providing Sentinel-1A data and the Japan Aerospace Exploration Agency (JAXA) for providing ALOS-2 PALSAR-2 data. We gratefully acknowledge the anonymous reviewers for giving constructive comments and suggestions to help improve earlier version of the manuscript.

Disclosure Statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [Grant Number 61427802, 41374016, 41330634].