Co- and post-seismic Deformation Mechanisms of the MW 7.3 Iran Earthquake (2017) Revealed by Sentinel-1 InSAR Observations

The extraction of high-accuracy coand post-seismic deformation fields and inversions of seismic slip distributions is significant in the comprehension of seismogenic mechanisms. On 12 November 2017, a MW 7.3 earthquake occurred on the border between Iran and Iraq. To construct the co-seismic deformation field, Sentinel-1A synthetic aperture radar (SAR) images from three tracks were used. Based on a prior knowledge, least-squares iterative approximation was employed to construct the three-dimensional (3D) co-seismic deformation field. to derive a time series of 2D post-seismic deformation, the multidimensional small baseline subset (MSBAS) technique was use. Co-seismic deformation fields were asymmetric; the maximum relative displacement was nearly 90cm in the radar line-of-sight between two centers of co-seismic deformation. The 3D co-seismic deformation field showed southwestward horizontal motion and continuous subsidence-to-uplift variation from northeast to southwest. The two-dimensional (2D) post-seismic deformation time series showed a gradual decaying trend and good correspondence with the aftershock distribution. The main mechanism of post-seismic deformation was an afterslip of the post-seismic faults. We used the elastic half-space model to invert co-seismic deformation fields and obtain source parameters of the slip model. The maximum and average slips were 2.5 and 0.72 m, respectively. The average slip angle was 126.38◦ and the moment magnitude was MW 7.34. The results of this study will contribute to research on regional tectonic activities.

[1]  Kaihua Ding,et al.  The 2017 Mw 7.3 Ezgeleh, Iran earthquake determined from InSAR measurements and teleseismic waveforms , 2018, Geophysical Journal International.

[2]  Kenneth W. Hudnut,et al.  Poroelastic rebound along the Landers 1992 earthquake surface rupture , 1998 .

[3]  William D. Barnhart,et al.  Ramp-flat basement structures of the Zagros Mountains inferred from co-seismic slip and afterslip of the 2017 Mw7.3 Darbandikhan, Iran/Iraq earthquake , 2018, Earth and Planetary Science Letters.

[4]  A. Hooper,et al.  Inversion of Surface Deformation Data for Rapid Estimates of Source Parameters and Uncertainties: A Bayesian Approach , 2018, Geochemistry, Geophysics, Geosystems.

[5]  Hugo Perfettini,et al.  Postseismic relaxation driven by brittle creep: A possible mechanism to reconcile geodetic measurements and the decay rate of aftershocks, application to the Chi-Chi earthquake, Taiwan , 2004 .

[6]  Sergey V. Samsonov,et al.  Multidimensional time‐series analysis of ground deformation from multiple InSAR data sets applied to Virunga Volcanic Province , 2012 .

[7]  C. Werner,et al.  Radar interferogram filtering for geophysical applications , 1998 .

[8]  F. Webb,et al.  Surface deformation and coherence measurements of Kilauea Volcano, Hawaii, from SIR C radar interferometry , 1996 .

[9]  Tomokazu Kobayashi,et al.  InSAR-derived Crustal Deformation and Reverse Fault Motion of the 2017 Iran-Iraq Earthquake in the Northwestern Part of the Zagros Orogenic Belt , 2018 .

[10]  Rui Zhang,et al.  Retrieving Three-Dimensional Co-Seismic Deformation of the 2017 Mw7.3 Iraq Earthquake by Multi-Sensor SAR Images , 2018, Remote. Sens..

[11]  Tomokazu Kobayashi,et al.  Estimation of coseismic deformation and a fault model of the 2010 Yushu earthquake using PALSAR interferometry data , 2011 .

[12]  H. Zebker,et al.  Fault Slip Distribution of the 1999 Mw 7.1 Hector Mine, California, Earthquake, Estimated from Satellite Radar and GPS Measurements , 2002 .

[13]  Rongjiang Wang,et al.  SDM - A geodetic inversion code incorporating with layered crust structure and curved fault geometry , 2013 .

[14]  Niels Bohr,et al.  Monte Carlo sampling of solutions to inverse problems , 2004 .

[15]  Sergey V. Samsonov,et al.  Multidimensional Small Baseline Subset (MSBAS) for Two-Dimensional Deformation Analysis: Case Study Mexico City , 2017 .

[16]  Zhong Lu,et al.  Deformation at longyao ground fissure and its surroundings, north China plain, revealed by ALOS PALSAR PS-InSAR , 2018, Int. J. Appl. Earth Obs. Geoinformation.

[17]  Wanpeng Feng,et al.  Geodetic Constraints of the 2017 Mw7.3 Sarpol Zahab, Iran Earthquake, and Its Implications on the Structure and Mechanics of the Northwest Zagros Thrust‐Fold Belt , 2018, Geophysical Research Letters.

[18]  Yang Cheng.  Obtaining an Atmospheric Delay Correction for Differential SAR Interferograms Based on Regression Analysis of the Atmospheric Delay Phase , 2012 .

[19]  Y. Okada.  Internal deformation due to shear and tensile faults in a half-space , 1992, Bulletin of the Seismological Society of America.

[20]  Soodabeh Soleymani,et al.  Accommodation of Arabia‐Eurasia convergence in the Zagros‐Makran transfer zone, SE Iran: A transition between collision and subduction through a young deforming system , 2004 .

[21]  Eric J. Fielding,et al.  Coseismic Deformation Field of the Mw 7.3 12 November 2017 Sarpol-e Zahab (Iran) Earthquake: A Decoupling Horizon in the Northern Zagros Mountains Inferred from InSAR Observations , 2018, Remote. Sens..

[22]  D. Sandwell,et al.  Three-dimensional deformation caused by the Bam, Iran, earthquake and the origin of shallow slip deficit , 2005, Nature.

[23]  Maorong Ge,et al.  The 2011 Mw 9.0 Tohoku Earthquake: Comparison of GPS and Strong‐Motion Data , 2013 .

[24]  K. Feigl,et al.  The displacement field of the Landers earthquake mapped by radar interferometry , 1993, Nature.

[25]  K. Feigl,et al.  Radar interferometry and its application to changes in the Earth's surface , 1998 .

[26]  P. Rosen,et al.  On the derivation of coseismic displacement fields using differential radar interferometry: The Landers earthquake , 1994, Proceedings of IGARSS '94 - 1994 IEEE International Geoscience and Remote Sensing Symposium.

[27]  W. K. Hastings,et al.  Monte Carlo Sampling Methods Using Markov Chains and Their Applications , 1970 .

[28]  Frederic Masson,et al.  Present‐day crustal deformation and plate kinematics in the Middle East constrained by GPS measurements in Iran and northern Oman , 2004 .

[29]  T. Wright,et al.  Toward mapping surface deformation in three dimensions using InSAR , 2004 .

[30]  Xiaoli Ding,et al.  Calibration of an InSAR-Derived Coseimic Deformation Map Associated With the 2011 Mw-9.0 Tohoku-Oki Earthquake , 2012, IEEE Geoscience and Remote Sensing Letters.

[31]  Chris Marone,et al.  On the mechanics of earthquake afterslip , 1991 .

[32]  Urs Wegmüller,et al.  Gamma SAR processor and interferometry software , 1997 .

[33]  N. McQuarrie,et al.  Crustal scale geometry of the Zagros fold–thrust belt, Iran , 2004 .

[34]  M. Eineder,et al.  Unwrapping large interferograms using the minimum cost flow algorithm , 1998, IGARSS '98. Sensing and Managing the Environment. 1998 IEEE International Geoscience and Remote Sensing. Symposium Proceedings. (Cat. No.98CH36174).

[35]  Roland Bürgmann,et al.  Damxung earthquake , Tibet , constrained by InSAR , 2013 .