Publication Date:
2022-05-26
Description:
Author Posting. © American Geophysical Union, 2010. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 115 (2010): B12418, doi:10.1029/2010JB007442.
Description:
We have developed a tool to detect transient deformation signals from large-scale (principally GPS) geodetic arrays, referred to as a Network Strain Filter (NSF). The strategy is to extract spatially and temporally coherent signals by analyzing data from entire geodetic networks simultaneously. The NSF models GPS displacement time series as a sum of contributions from secular motion, transient displacements, site-specific local benchmark motion, reference frame errors, and white noise. Transient displacements are represented by a spatial wavelet basis with temporally varying coefficients that are estimated with a Kalman filter. A temporal smoothing parameter is also estimated online by the filter. The problem is regularized in the spatial domain by minimizing a smoothing (Laplacian) norm of the transient strain rate field. To test the performance of the NSF, we carried out numerical tests using the Southern California Integrated GPS Network station distribution and a 3 year long synthetic transient in a 6 year time series. We demonstrate that the NSF can identify the transient signal, even when the colored noise amplitude is comparable to that of transient signal. Application of the method to actual GPS data from the Japanese GPS network (GEONET) on the Boso Peninsula also shows that the NSF can detect transient motions resulting from aseismic fault slip.
Description:
We thank the Grant‐in‐Aid for Young Scientists
[KAKENHI(18740283)] of the Ministry of Education, Culture, Sports,
Science and Technology of Japan and the postdoctoral fellowships for
research abroad of the Japan Society for the Promotion of Science. We also
acknowledge support from NASA grant NNG04GC93G. This research was
supported by the Southern California Earthquake Center. SCEC is funded
by NSF Cooperative Agreement EAR‐0529922 and USGS Cooperative Agreement 07HQAG0008.
Keywords:
Strain transients
Repository Name:
Woods Hole Open Access Server
Type:
Article
Format:
application/pdf
Permalink
