A Fine Velocity and Strain Rate Field of Present-Day Crustal Motion of the Northeastern Tibetan Plateau Inverted Jointly by InSAR and GPS

Song, Xiaogang, Jiang, Yu ORCID: 0000-0002-6238-9141, Shan, Xinjian, Gong, Wenyu and Qu, Chunyan (2019) A Fine Velocity and Strain Rate Field of Present-Day Crustal Motion of the Northeastern Tibetan Plateau Inverted Jointly by InSAR and GPS. REMOTE SENSING, 11 (4). p. 435.

Access the full-text of this item by clicking on the Open Access link.

Text
remotesensing-11-00435.pdf - Published version
Download (11MB) | Preview

Official URL: http://dx.doi.org/10.3390/rs11040435

Abstract

<jats:p>Interferometric synthetic aperture radar (InSAR) data from 6 Envisat ASAR descending tracks; spanning the 2003–2010 period; was used to measure interseismic strain accumulation across the Northeastern Tibetan Plateau. Mean line-of-sight (LOS) ratemaps are computed by stacking atmospheric-corrected and orbital-corrected interferograms. The ratemaps from one track with different atmospheric-corrected results or two parallel; partially overlapping tracks; show a consistent pattern of left-lateral motion across the fault; which demonstrates the MERIS and ECMWF atmospheric correction works satisfactorily for small stain measurement of this region; even with a limited number of interferograms. By combining the measurements of InSAR and GPS; a fine crustal deformation velocity and strain rate field was estimated on discrete points with irregular density depending on the fault location; which revealed that the present-day slip rate on the Haiyuan fault system varies little from west to east. A change (2–3 mm/year) in line-of-sight (LOS) deformation rate across the fault is observed from the Jinqianghe segment to its eastern end. Inversion from the cross-fault InSAR profiles gave a shallow locking depth of 3–6 km on the main rupture of the 1920 earthquake. We therefore infer that the middle-lower part of the seismogenic layer on the 1920 rupture is not yet fully locked since the 1920 large earthquake. Benefit from high spatial resolution InSAR data; a low strain accumulation zone with high strain rates on its two ends was detected; which corresponds to the creeping segment; i.e., the Laohushan fault segment. Contrary to the previous knowledge of squeezing structure; an abnormal tension zone is disclosed from the direction map of principal stress; which is consistent with the recent geological study. The distribution of principal stress also showed that the expanding frontier of the northeastern plateau has crossed the Liupan Shan fault zone; even arrived at the northeast area of the Xiaoguan Shan. This result agrees with the deep seismic reflection profile.</jats:p>

Item Type:	Article
Uncontrolled Keywords:	The Northeastern Tibetan Plateau, The Haiyuan fault, InSAR, GPS, velocity field, Strain rate field
Depositing User:	Symplectic Admin
Date Deposited:	16 Aug 2019 07:29
Last Modified:	19 Jan 2023 00:29
DOI:	10.3390/rs11040435
Open Access URL:	https://doi.org/10.3390/rs11040435
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3051908