On March 23, 2021 (21:14 universal time coordinated), an Mw 5.3 earthquake occurred in Baicheng County in Xinjiang, northwestern China, according to the United States Geological Survey. The earthquake produced a 4-km-long surface rupture at the epicenter, which is generally rare for earthquakes of magnitude 5.3. Thus, investigating the Baicheng earthquake is crucial for understanding the seismogenic structure of the region. We obtained the interferometric synthetic aperture radar deformation field and inverted the slip distribution of the Baicheng earthquake using Sentinel-1A satellite data and surface rupture data. The results indicate that the surface deformation area was elliptical, with long and short axes of approximately 20 and 10 km, respectively. The seismogenic structure is a left-lateral strike-slip fault with a small dip-slip component and strike and dip angles of 248° and 70°, respectively. Two other slip centers were also observed at 2 and 8 km beneath the surface in the dip direction. The maximum slip at 2 km was 0.45 m. Shear deformation between the Tarim Basin and Southern Tianshan Mountains was responsible for the strike-slip features of the Baicheng earthquake.
At 21:14 universal time coordinated on March 23, 2021, an Mw 5.3 earthquake occurred in Baicheng County, Xinjiang Uyghur Autonomous Region, northwestern China. The epicenter was located at 41.82° N and 81.16° E and had a focal depth of 10 km, according to the United States Geological Survey (USGS). The earthquake epicenter was located in the Baicheng Basin, 64 km west of Baicheng County in the southern Tianshan Mountains. The Baicheng Basin is a structural depression between the southern Tianshan tectonic belt to the north and the Qiulitag anticline to the south and is located over a series of nearly east–west-trending fold structures. Owing to the collision of the Indian and Eurasian plates, which causes extensive deformation in Eurasia, the landforms in western China are characterized by alternating mountains and basins . The northern margin of the Tarim Basin is the Tianshan arc ridge. A large number of northward-thrusting faults formed between the ridge and basin, which have caused a series of thrust earthquakes in these areas. According to the results of the global positioning system (GPS) velocity field at the Baicheng earthquake epicenter and in the surrounding area, the horizontal GPS velocity on the northern margin of the Tarim Basin is ∼15 mm/year; however, the velocity near the Qiulitag Fault and Kumugeremu Fault Zone is ∼7 mm/year, indicating that the region absorbs a horizontal velocity of ∼8 mm/year . The long-term velocity of the Qiulitag Fault Zone is only 1–4 mm/year based on geological surveys , which is far less than the GPS velocity. It has been speculated that a series of parallel fold and thrust belts located at the intersection of the Tarim Basin and South Tianshan Mountains absorbs most of the horizontal velocity . The Baicheng Mw 5.3 earthquake occurred at the intersection of the Tarim Basin and the foothills of the South Tianshan Mountains, which has the largest GPS horizontal shortening rate in the region.
Large-scale faults are located on both sides of the Baicheng Basin: the Kumugeremu and Kasangtuokai faults to the north and the Qiulitag Fault to the south, all of which have been active since the late Pleistocene . Based on the focal mechanism solutions of historical earthquakes with magnitudes >5 since 1976, the earthquakes that occur in this region are mainly thrust events [6,7] (Figure 1). A magnitude 5.7 earthquake occurred on January 5, 1987, and two magnitude 5.1 earthquakes occurred on September 26, 1995, and July 28, 1998, near the epicenter of the Baicheng earthquake, both of which were thrust events. The focal depths of the two M 5.1 earthquakes reached 40 km, whereas the 1987 M 5.7 earthquake had a focal depth of 15 km, indicating that the seismogenic environment in the region is complex . The Global Centroid Moment Tensor (GCMT) and other agencies obtained the source parameters of the March 23, 2021, Baicheng earthquake (Table 1), but the results differed. Investigating the seismogenic structure of earthquakes is an effective method for understanding the blind faults in this region and is important for understanding the tectonic units around the foothills of the South Tianshan Mountains and Tarim Basin.
|Source||Longitude (°)||Latitude (°)||Depth (km)||Strike (°)||Dip (°)||Rake (°)||Magnitude (Mw)|
|Yao et al. ||0.5–2||246||70||12||5.9|
Interferometric synthetic aperture radar (InSAR) has the advantages of high spatial and temporal resolutions, low operational costs, and wide geographic coverage compared to the global navigation satellite system (GNSS). Crustal deformation data with a high spatial resolution can also be obtained without ground control points, and important constraining parameters can be provided for slip distribution inversion. InSAR has been widely used for geologic hazard monitoring since the beginning of the twenty-first century, owing to the development of synthetic aperture radar (SAR) satellites and processing technology. Researchers have introduced this technology into seismic research, particularly in recent years, including high spatial resolution InSAR deformation field acquisition [9,10,11], seismogenic structure analysis [12,13,14], slip distributions and seismogenic fault plane analysis [15,16], and the locking characteristics of active faults [17,18]. Inversion of source slip distributions requires reliable observations, and seismic waveforms, GNSS, and InSAR can provide the appropriate data constraints for inversion. InSAR has a higher spatial resolution than GNSS and can provide continuous surface deformation coverage. GNSS stations are sparse in the region around the epicenter of the Baicheng earthquake, and no GNSS data were available for the region near the epicenter prior to the event. Therefore, InSAR provides the best data source for the focal slip distribution inversion of the Baicheng earthquake.
Previous studies of co-seismic deformation have mostly focused on earthquakes with M ≥ 6, as the surface deformation caused by strong earthquakes is relatively large in most cases. We performed a field survey after the Baicheng earthquake and observed a 4 km surface rupture length at the epicenter. Surface ruptures caused by faulting are rarely reported for M < 6 earthquakes; thus, the Baicheng earthquake provides a unique opportunity to improve seismic hazard knowledge associated with moderate events [19,20,21,22]. Yao et al.  studied the seismogenic structure of the 2021 Mw 5.3 Baicheng earthquake using InSAR data and unmanned aerial vehicle images and observed two deformation centers on the interferometric images. They proposed that the Baicheng event was a left-lateral strike-slip earthquake caused by the rupture of a buried compressional salt–related structure. However, they did not discuss the reason for the two adjacent deformation centers observed at the surface. In this study, we used two sets of Sentinel-1A satellite data (before and after the Baicheng earthquake) to obtain the deformation field using differential InSAR technology, from which we inverted the slip distribution. The characteristics of the seismogenic structure were also analyzed based on the InSAR and surface rupture data.
2 Data and methods
The Sentinel-1 satellite data were obtained from the European Space Agency (ESA) . A single Sentinel-1 satellite image has a width of 250 km, which covers the entire deformation area of the Baicheng earthquake and provides a good data source for deformation processing with InSAR . Although ESA provides Sentinel-1 ascending and descending satellite data, only the ascending data (tracks T158 and T085) were available for the Baicheng earthquake. After comparing the SAR data processing results from the two tracks, data from track 158 had better interferometric results and was therefore selected to obtain the deformation field of the Baicheng earthquake. The acquisition times of the two images were March 13 and 25, the temporal baseline of the interferometric image pair was 12 days, and the perpendicular baseline was 30 m. The parameters of the interferometric image pairs are listed in Table 2, and the spatial coverage area of the track 158 images is shown in Figure 1. The Shuttle Radar Topographic Mission digital elevation model with has a 30 m spatial resolution [26,27] obtained from the Consultative Group on International Agricultural Research Consortium for Spatial Information was used for topography removal. Precise orbit ephemerides  from the Copernicus precise orbit determination service were used for co-registration, and the GMTSAR software package  was used to obtain the deformation field of the Baicheng earthquake.
To further understand the characteristics of crustal motion at the epicenter and in the surrounding area before the Baicheng earthquake, we obtained GPS data from 1998 to 2018 [2,30,31] and plotted the horizontal GPS velocities relative to the Eurasian plate, as well as the shear strain rates in the region.
Calculating the slip distribution of seismogenic faults is an effective method for understanding seismogenic structures. We determined a geometric model of the seismogenic faults based on the deformation field obtained from the InSAR data and surface rupture characteristics. The slip distribution of the seismogenic fault was then inverted and constrained by the surface deformation data. The line-of-sight (LOS) deformation field of the Baicheng earthquake was obtained from the ascending orbit data using the two-pass differential InSAR method [32,33,34]. An adaptive filtering method  was adopted for the interferograms to reduce phase noise and acquire a higher signal-to-noise ratio. The minimum cost flow was adopted to unwrap the filtered phase , and the unwrapped interferograms were geocoded to the World Geodetic System 1984 geographic coordinates. The geometric parameters of the seismic faults were inverted based on an elastic half-space model . The steepest descent method with constrained least-squares optimization was used to conduct the geodetic inversion by minimizing the root-mean-square misfit between the observations and the model . This method can be applied to co-seismic slip distribution inversion, can restrain stress drop or slip smoothing between the fault planes, and has been used by recent studies to analyze GPS and InSAR co-seismic deformation data [39,40,41]. Since the deformation field obtained by InSAR contains tens of thousands of pixels, the program efficiency is reduced considerably when used directly for slip inversion. Therefore, the quadtree method  was used to downsample the deformation field data, which effectively reduced the amount of deformation field data used for the inversion without affecting the inversion quality.
The slip distribution inversion requires a fault geometry model. The initial values of the fault parameters were set to a strike of 230–270° and a dip of 10–90° based on field investigations and deformation field results combined with the focal mechanism solutions obtained from other agencies. The fault plane was divided into 1 km × 1 km sub-fault planes, and the slip distribution of each sub-fault plane was fitted using the steepest descent method with least squares optimization to invert the slip distribution of the entire fault surface. The slip distribution is dependent on the weight of the smoothing constraint , which we set as 0.05 for this study.
3.1 Interferometric displacement
This study only provides the LOS deformation of the ascending data owing to data availability. The deformation interferogram indicates that the surface deformation caused by the Baicheng earthquake had an elliptical distribution, with a long axis of ∼20 km (east–west) and a short axis of ∼10 km (north–south). The long axis of the deformation field is approximately in the SWW direction, which is consistent with the westward extension of the Kumugeremu Fault. The deformation field is also symmetrically distributed on the northern and southern sides of the fault extension. The density and number of interference fringes indicate fault deformation, and the denser interference fringes represent a larger spatial gradient of surface deformation . The interferogram (Figure 2a) includes approximately three color-cycle changes on the northern side of the fault, indicating that the northern side of the fault was displaced by ∼10 cm in the LOS direction. The southern side of the fault includes 2.5 color cycles, indicating that the southern side of the fault was displaced by ∼9 cm. The deformation stripes were also divided into eastern and western sections. The spatial range of the stripes on the eastern side was larger than that on the western side, and the color cycles had the same pattern, indicating that the deformation caused by the earthquake exhibited two adjacent displacement areas in the east and west.
Two profiles located perpendicular to the fault strike (A–A’ and B–B’, black dashed lines in Figure 2b) were generated in the eastern and western sections of the deformation area to more intuitively analyze the surface deformation caused by the Baicheng earthquake. Both profiles pass through the surface deformation area on both sides of the fault. Profile A–A’ (Figure 2c) is located in the western section, in which the northern side of the fault was displaced by 10 cm in the LOS direction, whereas the southern side was displaced by 2 cm in the opposite direction. Profile B–B’ (Figure 2d) is located in the eastern section, in which the northern side of the fault was displaced by 9 cm in the LOS direction, whereas the southern side was displaced by 10 cm in the opposite direction. Both profiles changed rapidly at the fault trace, indicating that deformation was strongest near the fault, which is consistent with the results of the surface rupture field surveys.
3.2 Slip distribution
Based on the inversion results (Figure 3), the slip distribution of the Mw 5.3 Baicheng earthquake was consistent with the surface deformation characteristics. Two slip centers were observed at 8 and 2 km in the dip direction. The maximum slip occurred at the western slip center (0.45 m), and the eastern slip center underwent 0.4 m of slip. The inversion results of the slip distribution indicate that a certain amount of slip occurred at the surface. The rupture zone at the surface was 4 km long and exhibited characteristics of a left-lateral strike-slip event with a dip-slip component. The maximum vertical dislocation was 0.12 m and the horizontal dislocation was 0.1 m, according to the field surveys (Figure 4). The amount of slip and the geographic location of the inverted distribution that extended to the surface obtained herein were similar to the field survey results, indicating that the inversion results are reliable. The final inversion results indicate that the seismogenic fault had strike, dip, and rake angles of 248°, 70°, and 22°, respectively; a maximum slip of 0.45 m; and a moment magnitude (Mw) of 5.7 derived from the geodetic data. The deformation epicenter was located at 41.79° N and 81.13° E. The surface LOS deformation simulated by the model is shown in Figure 5, the results of which are in agreement with the InSAR deformation results. The data–model correlation was as high as 99.3%, and the average residual was 4 mm.
The results indicate that the 2021 Baicheng earthquake was a left-lateral strike-slip rupture event with a small dip-slip component. The moment magnitude obtained herein was higher than those obtained by the USGS and GCMT. A magnitude 4.9 foreshock occurred on March 14, and the acquisition time of the primary SAR image was one day before the foreshock. The acquisition time of the secondary SAR image was two days after the Baicheng mainshock; thus, the foreshock and post-seismic deformation were present in the interferograms used to invert the slip distribution. The higher magnitude obtained herein may also be due to the sensitivity of InSAR to shallow events. As the largest rupture zone obtained from the inverted slip model was located at ∼2 km in the dip direction, some enhancement of the slip values may have occurred in the inversion results.
The geometry of the seismogenic fault obtained from the InSAR data confirmed that it was a left-lateral strike-slip fault with a dip-slip component, which was corroborated by the surface rupture field survey results. Thus, this event occurred along a fault with a strike of 248° and a dip of 70° between the Tarim Basin and the southern Tianshan Mountains.
The most prominent feature of the Baicheng Mw 5.3 earthquake was the presence of two independent surface deformation centers. Several other events have exhibited this feature, including the 1999 Mw 7.6 İzmit et al. , 2004 Mw 6.0 Parkfield , and 2010 Mw 6.9 Yushu earthquakes . The slip model inverted from the InSAR results also contained two rupture zones in the source area that were connected to each other. The western rupture center contained the maximum slip, but had a smaller distribution area. This result may be due to the fact that the interferometric map of the earthquake had two deformation centers. Nine days before the Mw 5.3 earthquake (March 14, 2021), an Mw 4.9 foreshock (41.88° N and 81.18° E) occurred, according to the USGS. The surface deformation data used for the inversion were obtained from two SAR images taken during March 13–25, which included deformation from both the March 14 foreshock and the March 23 mainshock. To determine whether the foreshock and mainshock caused two separate deformation areas at the surface and the influence of the foreshock on the deformation field, we selected another two SAR data pairs acquired on March 20 and April 13, 2021, from which we obtained the surface deformation that excludes the effect of the Mw 4.9 foreshock (Figure 6). The results indicate two deformation centers at the surface, which is similar to the deformation patterns caused by both the foreshock and mainshock. Therefore, we inferred that the Mw 5.3 Baicheng earthquake simultaneously formed two adjacent deformation fields at the surface.
Petroleum exploration in the study area has yielded many seismic sections and boreholes, as well as structural studies. To analyze the seismogenic structural characteristics of this earthquake, we collected the results  of seismic reflection profiles across the epicenter region (Figure 7). The epicenter is located west of the Kuqa fold belt, and the main structural feature on the northern side of the area is a southward-dipping monocline above a northward-dipping reverse fault in the Paleozoic basement. In contrast, a large number of salt structures are developed on the southern side of the region. Gypsum-salt rocks occur along the Qiulitag reverse fault zone on the surface of the north wing of the Miskantak anticline. Salt structures are also located between the Cretaceous and Neogene strata in this area. The deepest rupture of the Baicheng earthquake was located at the junction of the buried fault’s Triassic and Cretaceous strata in front of the South Tianshan Mountains, according to a shallow structural cross-section of the Kuqa fold belt. Paleo-modern Kumgarmu Group gypsum-salt strata with a maximum thickness of >3 km overlie the Cretaceous strata. The gypsum-salt strata have strong plasticity and flow easily, leading to gaps and small faults that can be filled by salt rocks, which require large breakthrough pressures for rupture to occur . When an earthquake rupture occurs and the seismic wave passes through tight gypsum strata, the brittle plastic rock strata suddenly rupture, which likely produces a second rupture center near the source area and increases the intensity of the rupture. The slip distribution results obtained herein also indicate that the rupture depth on the western side was only 2 km, which is also the depth of the gypsum-salt rock strata. This process can explain why the Mw 5.3 earthquake produced such large-scale surface ruptures and deformation fields.
The horizontal velocity field derived from GNSS data (Figure 8a) indicates that the 15 mm/year average velocity in the Tarim Basin was reduced to 7 mm/year in the earthquake epicenter area. The thrust fault zone between the Tarim Basin and South Tianshan Mountains absorbs the northward velocity. There are a number of differences in the GPS velocities between the epicenter and surrounding areas: the direction of the GPS-derived velocity east of the epicenter is more westward than that on the western side, indicating that shear strain accumulation occurs in this region. Shear strain rate calculations (Figure 8b) indicate that the maximum horizontal principal strain is north–south throughout the entire study area, suggesting that a north–south compressive stress state exists between the Tarim Basin and the South Tianshan Mountains.
To visualize the slip rate of the seismogenic fault, a profile perpendicular to the fault strike was plotted across the epicenter (black dashed line in Figure 8a). A total of 14 GPS monitoring points within 150 km on both sides of the profile were projected onto the profile, and the south–north (Figure 8c) and west–east (Figure 8d) GPS velocity components were plotted. Obvious shortening was observed in the GPS velocities near the epicenter, and the influence of the seismogenic fault on the regional GPS velocities and strain states was considerably larger than those of the other surrounding faults.
The deformation field of the Mw 5.3 Baicheng earthquake was calculated using Sentinel-1A satellite data. Combined with the field survey data, the geometric characteristics of the seismogenic fault and source slip distribution were obtained through inversion. The following conclusions were obtained:
The seismogenic structure of the Baicheng earthquake was a left-lateral strike-slip motion with a small dip-slip component. Based on the fault parameters and location, we inferred that the seismogenic fault is a blind fault with strike and dip angles of 248° and 70°.
The maximum slip was 0.45 m, which occurred 2 km beneath the surface in the dip direction. Another slip center was located to the east of the maximum slip center, which underwent 0.4 m of slip at a depth of ∼8 km in the dip direction. A moment magnitude of Mw 5.7 was obtained from geodetic and surface rupture data, and the source rupture extended to the surface. The combined co-seismic and post-seismic deformation from the foreshock and mainshock was the main reason for the higher magnitude obtained from our inversion. The surface slip obtained from the inversion was 0.1–0.3 m, which is consistent with the surface rupture field survey results.
The Mw 5.3 Baicheng earthquake was a shallow event, and the source rupture extended to the surface. Moreover, the surface deformation field and slip distribution obtained via inversion indicate that the earthquake produced two rupture centers in the epicenter area.
The analysis of inter-seismic GPS deformation characteristics indicates that slight shear strain accumulation occurs in the epicenter region, which may be responsible for the strike-slip features observed in our slip distribution model.
We are particularly grateful to the ESA for providing the Sentinel data and to German Research Centre for Geosciences (GFZ) for providing the SDM software package. Some of the figures were drawn using Generic Mapping Tools 5.4 by Wessel and Smith . We want to provide our gratitude to the editors and the anonymous reviewers.
Funding information: This work was supported by the Science for Earthquake Resilience of China Earthquake Administration (XH22007YA), Key R&D Program of Xinjiang Uygur Autonomous Region (2020B03006-2 and 2022B03001-1), the National Natural Science Foundation of China (42274014), Strategic Priority Research Program (B) of the Chinese Academy of Sciences (XDB18000000), and the Natural Science Foundation of Xinjiang Uygur Autonomous Region (2020D01A84, 2020D01A85, and 2022D01A106).
Author contributions: D.L. contributed to the conception of the paper and supervision. S.Y. performed the data processing. A.Yu. and L.C. contributed significantly to data analysis and manuscript preparation. A.Yu. and J.L. performed the data analyses and wrote the manuscript. J.L. helped perform the analysis with constructive discussions. A.Ya. performed the field survey. A.Yu. and D.L. revised the manuscript.
Conflict of interest: The authors state that they have no conflict of interest.
Data availability statement: The datasets produced for this study are available from the corresponding author on reasonable request.
 Molnar P, Tapponnier P. Cenozoic tectonics of Asia: Effects of a continental collision: Features of recent continental tectonics in Asia can be interpreted as results of the India-Eurasia collision. Science. 1975;189(4201):419–26.10.1126/science.189.4201.419Search in Google Scholar PubMed
 Zheng G, Wang H, Wright TJ, Lou Y, Zhang R, Zhang W, et al. Crustal deformation in the India–Eurasia collision zone from 25 years of GPS measurements. J Geophys Res. 2017;122(11):9290–312.10.1002/2017JB014465Search in Google Scholar
 Lu H, Wang S, Jia D, Suppe J, Hubert-Ferrari A, Yin D, et al. Quaternary folding in the south piedmont of central segment of Tianshan Mountains. Chin Sci Bull. 2002;47(22):1907–11.10.1360/02tb9417Search in Google Scholar
 Wang X, Jia C, Yang S, Hubert-Ferrari A, Suppe J. The deformation time of Kuqa fold-and-thrust belt in the southern Tianshan. Acta Geol Sin. 2002;76:55–63.Search in Google Scholar
 Zhang L, Yang X, Huang W, Yang H, Li S. Fold segment linkage and lateral propagation along the Qiulitage anticline, South Tianshan, NW China. Geomorphol. 2021;381(3):107662.10.1016/j.geomorph.2021.107662Search in Google Scholar
 Dziewonski A, Chou T, Woodhouse J. Determination of earthquake source parameters from wave-form data for studies of global and regional seismicity. J Geophys Res. 1981;86(B4):2825–52.10.1029/JB086iB04p02825Search in Google Scholar
 Ekström G, Nettles M, Dziewonski AM. The global CMT project 2004–2010: Centroid-moment tensors for 13017 earthquakes. Phys Earth Planet Inter. 2012;200–201:1–9.10.1016/j.pepi.2012.04.002Search in Google Scholar
 Wang X, Suppe J, Guan S, Hubert-Ferrari A, Gonzalez MR, Jian C. Cenozoic structure and tectonic evolution of the Kuqa fold belt, southern Tianshan, China. Am Assoc Pet. 2011;94:215–43.10.1306/13251339M94389Search in Google Scholar
 Ji L, Zhang W, Liu C, Zhu L, Xu J, Xu X. Characterizing interseismic deformation of the Xianshuihe fault, eastern Tibetan Plateau, using Sentinel-1 SAR images. Adv Space Res. 2020;66(2):378–94.10.1016/j.asr.2020.03.043Search in Google Scholar
 Zhang G, Shan X, Feng G. The 3-D surface deformation, coseismic fault slip and after-slip of the 2010 Mw6.9 Yushu earthquake, Tibet, China. J Asian Earth Sci. 2016;124(1):260–8.10.1016/j.jseaes.2016.05.011Search in Google Scholar
 Ji L, Liu C, Xu J, Liu L, Zhang Z. InSAR observation and inversion of the seismogenic fault for the 2017 Jiuzhaigou MS7.0 earthquake in China. Chin J Geophys. 2017;60(10):4069–82 (in Chinese with English summary).Search in Google Scholar
 Gunawan E, Nishimura T, Susilo S, Widiyantoro S, Puspito N, Sahara D, et al. Fault source investigation of the 6 December 2016 Mw 6.5 Pidie Jaya, Indonesia, earthquake based on GPS and its implications of the geological survey result. J Appl Geodesy. 2020;14(4):405–12.10.1515/jag-2020-0027Search in Google Scholar
 Hong S, Liu M, Liu T, Dong Y, Chen L, Meng G, et al. Fault source model and stress changes of the 2021 Mw 7.4 Maduo earthquake, China, constrained by InSAR and GPS measurements. Bull Seismol Soc Am. 2022;112(3):1284–96.10.1785/0120210250Search in Google Scholar
 Zhang Y, Wang Y, Duan H, Gao Y, Jiao J. A non-uniform dip slip formula to calculate the coseismic deformation: Case study of Tohoku Mw 9.0 Earthquake. Open Geosci. 2019;11(1):1014–24.10.1515/geo-2019-0078Search in Google Scholar
 Qiao X, Wang Q, Yang S, Li J. Study on the focal mechanism and deformation characteristics for the 2008 Mw 6.7 Wuqia earthquake, Xinjiang by InSAR. Chin J Geophys. 2014;57(6):1805–13 (in Chinese with English summary).Search in Google Scholar
 Sreejith KM, Sunil PS, Agrawal R, Saji AP, Rajawat AS, Ramesh DS. Audit of stored strain energy and extent of future earthquake rupture in central Himalaya. Sci Rep. 2018;8(1):16697.10.1038/s41598-018-35025-ySearch in Google Scholar PubMed PubMed Central
 Champenois J, Baize S, Vallee M, Jomard H, Alvarado AP, Espin P, et al. Evidences of surface rupture associated with a low-magnitude (Mw5.0) shallow earthquake in the Ecuadorian Andes. J Geophys Res Solid Earth. 2017;122(10):8446–58.10.1002/2017JB013928Search in Google Scholar
 Figueiredo PM, Hill JS, Merschat AJ, Scheip CM, Stewart KG, Owen LA, et al. The Mw 5.1, 9 August 2020, Sparta earthquake, North Carolina: The first documented seismic surface rupture in the eastern United States. Geol Soc Am. 2022;32(3–4):4–11.10.1130/GSATG517A.1Search in Google Scholar
 Baize S, Nurminen F, Sarmiento A, Dawson T, Takao M, Scotti O, et al. A worldwide and unified database of surface ruptures (SURE) for fault displacement hazard analyses. Seismol Res Lett. 2020;91(1):499–520.10.1785/0220190144Search in Google Scholar
 Ritz JF, Baize S, Ferry M, Larroque C, Audin L, Delouis B, et al. Surface rupture and shallow fault reactivation during the 2019 Mw 4.9 Le Teil earthquake, France. Commun Earth Environ. 2020;10(1):1–11.10.1038/s43247-020-0012-zSearch in Google Scholar
 Yao Y, Wen S, Yang L, Wu C, Sun X, Wang L, et al. A shallow and left-lateral rupture event of the 2021 Mw 5.3 Baicheng earthquake: Implications for the diffuse deformation of Southern Tianshan. Earth Space Sci. 2022;9(3):e2021EA001995.10.1029/2021EA001995Search in Google Scholar
 Margpany M, Cracknell AP, Hashim M. 3-D visualizations of coastal bathymetry by utilization of airborne TOPSAR polarized data. Int J Digital Earth. 2010;3(2):187–206.10.1080/17538940903477406Search in Google Scholar
 https://scihub.copernicus.eu/gnss.Search in Google Scholar
 Wang M, Zheng K. Present‐day crustal deformation of continental China derived from GPS and its tectonic implications. J Geophys Res Solid Earth. 2020;125:2.10.1029/2019JB018774Search in Google Scholar
 Yu J, Tan K, Zhang C, Zhao B, Wang D, Li Q. Present-day crustal movement of the Chinese mainland based on global navigation satellite system data from 1998 to 2018. Adv Space Res. 2019;63(2):840–56.10.1016/j.asr.2018.10.001Search in Google Scholar
 Pepe A, Lanari R. On the extension of the minimum cost flow algorithm for phase unwrapping of multitemporal differential SAR interferograms. IEEE Trans Geosci Remote. 2006;44(9):2374–83.10.1109/TGRS.2006.873207Search in Google Scholar
 Wang R, Diao F, Hoechner A. SDM–A geodetic inversion code incorporating with layered crust structure and curved fault geometry. Proceedings of the General Assembly European Geosciences Union. Vienna, Austria: 7–12 April 2013.Search in Google Scholar
 Diao F, Xiong X, Wang R, Zheng Y, Walter TR, Weng HL, et al. Overlapping post-seismic deformation processes: afterslip and viscoelastic relaxation following the 2011 Mw 9.0 Tohoku (Japan) earthquake. Geophys J Int. 2014;196(1):218–29.10.1093/gji/ggt376Search in Google Scholar
 Liu X, Chen Q, Yang Y, Xu Q, Zhao J, Xu L, et al. The 2021 Mw7.4 Maduo earthquake: Coseismic slip model, triggering effect of historical earthquakes and implications for adjacent fault rupture potential. J Geodyn. 2022;151:101920.10.1016/j.jog.2022.101920Search in Google Scholar
 Reilinger RE, Ergintav S, Bürgmann R, McClusky S, Lenk O, Barka A, et al. Coseismic and postseismic fault slip for the 17 August 1999, M = 7.5, İzmit, Turkey earthquake. Science. 2000;289:1519–24.10.1126/science.289.5484.1519Search in Google Scholar PubMed
 Kim A, Dreger DS. Rupture process of the 2004 Parkfield earthquake from near-fault seismic waveform and geodetic records. J Geophys Res. 2008;113:B07308.10.1029/2007JB005115Search in Google Scholar
 Li Z, Elliott JR, Feng W, Jackson JA, Parsons BE. The 2010 Mw 6.8 Yushu (Qinghai, China) earthquake: Constraints provided by InSAR and body wave seismology. J Geophys Res. 2011;116:B10302.10.1029/2011JB008358Search in Google Scholar
 Zhao B, Bürgmann R, Wang D, Zhang J, Yu J, Li Q. Aseismic slip and recent ruptures of persistent asperities along the Alaska-Aleutian subduction zone. Nat Commun. 2022;13:3098.10.1038/s41467-022-30883-7Search in Google Scholar PubMed PubMed Central
 Motagh M, Bahroudi A, Haghighi MH, Samsonov S, Fielding E, Wetzel HU. The 18 August 2014 Mw 6.2 Mormori, Iran, Earthquake: A thin-skinned faulting in the Zagros Mountain inferred from InSAR measurements. Seismol Res Lett. 2015;86(3):775–82.10.1785/0220140222Search in Google Scholar
 Jonsson S. Fault slip distribution of the 1999 Mw 7.1 Hector mine, California, earthquake, estimated from satellite radar and GPS measurements. Bull Seismol Soc Am. 2002;92(4):1377–89.10.1785/0120000922Search in Google Scholar
 Zhou C, Liu G, Chen Y, Wang K. Analysis of the source parameters of 2017 Iraq Mw 7.3 earthquake using Sentinel-1A InSAR data. J Geodesy Geodyn. 2019;39(6):577–82 (in Chinese with English summary).Search in Google Scholar
 Wang M, Sun Y, Luo G, Zhang R. Stress perturbations around the deep salt structure of Kuqa depression in the Tarim Basin. Interpret. 2019;7(3):T647–56.10.1190/INT-2018-0177.1Search in Google Scholar
 Hu J, Liu Y, Yang M, Zheng D, Zhou L. Salt structure characteristics and its relation to hydrocarbon accumulation in the Kuqa depression, Tarim Basin. Chin J Geol. 2004;39(4):580–8 (in Chinese with English summary).Search in Google Scholar
© 2022 the author(s), published by De Gruyter
This work is licensed under the Creative Commons Attribution 4.0 International License.