Monitoring Aseismic Slip Spatial and Temporial Behavior Along the Haiyuan Fault, Gansu, China
Abstract
A recent InSAR based study revealed the presence of shallow aseismic slip during the interseismic period in between two major seismogenic sections of the Haiyuan fault, Gansu, China. Here, we apply a time series analysis on a densely sampled InSAR data set on 1 descending and 2 ascending tracks to explore the spatial and temporal evolution of the shallow creep. Interferograms are computed using ROI PAC and the NSBAS processing chain, that maximizes the coherence over rough topography. Using a SBAS analysis and a low-pass filtering method, we separate the coherent deformation signal from the turbulent, random in space and time, residual atmospheric phase screen to enhance the signal to noise ratio. Our results suggest a horizontal creep rate increase period between 2007 and 2008, revealing a complex temporal behavior of the shallow fault zone. Such rate increase is visible on both ascending and descending tracks with opposite signs, suggesting the horizontal component is affected. We then model this acceleration using the Principal Component Analysis InversionMethod, revealing a complex slip distribution along the fault plane. Finally, as we observe both spatial and temporal coincidence, we conclude that nearby earthquakesmay have triggered that accelerating creep rate period.
- Publication:
-
Dragon 2 Final Results and Dragon 3 Kickoff Symposium
- Pub Date:
- January 2013
- Bibcode:
- 2013ESASP.704E..40J