Coulomb Stress Characteristics and Fault Slip Distribution of the 2023 Mw 6.1 Earthquake in Jishishan County (Gansu, China) Based on InSAR Observations

doi:10.21203/rs.3.rs-4787159/v1

Download PDF

Research Article

Coulomb Stress Characteristics and Fault Slip Distribution of the 2023 Mw 6.1 Earthquake in Jishishan County (Gansu, China) Based on InSAR Observations

https://doi.org/10.21203/rs.3.rs-4787159/v1

This work is licensed under a CC BY 4.0 License

You are reading this latest preprint version

On December 18, 2024, a M_w 6.1 earthquake occurred in Jishishan County, Linxia Prefecture, Gansu Province. This earthquake is the largest recorded since the establishment of seismic observations on the Laji Mountain fault zone along the northeastern edge of the Tibetan Plateau. This study utilizes Sentinel-1A satellite data to obtain the coseismic deformation field from ascending and descending tracks of the 2023 Jishishan earthquake, using this information to constrain the inversion of the earthquake's fault kinematic parameters and fault slip distribution characteristics. Finally, integrating the characteristics of Coulomb stress changes with regional tectonic background research results, we assess the seismic hazard of the region. The study indicates that the deformation field generated by this earthquake is oriented predominantly in the NNW direction, with the coseismic deformation from both ascending and descending tracks mostly exhibiting uplift. The maximum line-of-sight (LOS) displacement for the ascending track is approximately 6 cm, while for the descending track it is about 6.7 cm. The results of slip testing on the coseismic fault suggest that both east-dipping and west-dipping fault geometric models can adequately explain the parameters of the fault that caused this earthquake. Based on aftershock relocation and comprehensive analysis of the regional tectonic background, the study concludes that the rupture likely occurred on a northeast-dipping fault, potentially a concealed reverse fault with an NNW orientation located along the southern margin of Laji Mountain. Calculations of static Coulomb stress changes indicate that the occurrence of the 2023 Jishishan earthquake has increased the risk of future seismic events along segments of the NWW-oriented southern and northern margins of the Laji Mountain fault, as well as to the east of the epicenter along the Xiqinling northern fault and the Daotanghe-Linxia fault.

2023 Jishishan earthquake

InSAR

fault slip distribution

Coulomb stress changes

According to the China Earthquake Networks Center (CENC), a M_w 6.1 earthquake occurred on December 18, 2023, at 23:59 Beijing time in Jishishan County, Linxia Prefecture, Gansu Province, China (35.7° N, 102.79° E). The depth of the epicentre was 10 km, and the maximum intensity reached VIII. By 08:00 on December 22, 2023, a total of 2,632 early aftershocks (0 ≤ Ms ≤ 5) had been recorded, including 12 aftershocks with a magnitude of 3.0 or higher. The aftershocks displayed a linear distribution trending nearly northwest-southeast (Fig. 1 (c)). This earthquake resulted in 151 fatalities and 983 injuries, along with the destruction of 4,782 houses, triggering severe secondary disasters such as mudslides, landslides, and soil liquefaction. Source mechanism solutions from three organizations—the China Earthquake Networks Center, Harvard University’s Global Centroid Moment Tensor (GCMT), and the United States Geological Survey (USGS)—indicate that the Jishishan earthquake likely occurred on a high-angle reverse fault trending NNW or a low-angle reverse fault trending SSE (Table 1). This is consistent with the spatial distribution of the aftershock sequence. Influenced by the ongoing expansion between the Indian Plate and the Eurasian Plate, the northeastern margin of the Tibetan Plateau is undergoing shear deformation and crustal shortening and thickening, resulting in a series of active strike-slip and reverse fault zones (Fig. 1 (a)). Among these, the Laojishan Fault Zone features two prominent arc-shaped reverse structures, the Laojishan North Fault (~ 230 km) and the Laojishan South Fault (~ 220 km), both projecting northeast (Fig. 1 (b), Yuan et al., 2005). This fault zone has a historical precedent of strong seismic activity, with 20 recorded earthquakes of magnitude 5 or higher (Yang et al., 2024). The occurrence of this earthquake provides a natural experimental setting for utilizing satellite geodesy data to study the geometric and kinematic characteristics of the active faulting in the Laojishan Fault Zone.

This study first reconstructs the high-precision co-seismic deformation field of the M_w 6.0 earthquake that occurred in Jishi Mountain, Gansu Province, in 2023 using ascending and descending satellite image data from Sentinel-1A. Subsequently, based on the Okada elastic half-space rectangular dislocation model (Okada, 1985), the co-seismic rupture characteristics of this earthquake are inverted. This analysis integrates aftershock sequences, regional tectonic background, and co-seismic interference features to examine the fault geometry and kinematic characteristics of the earthquake. Finally, the static Coulomb failure characteristics are calculated to assess the potential seismic hazards in the region.

In panel (a), the red lines indicate secondary block boundaries (Zhang et al., 2005), while the blue arrows represent the interseismic GPS velocity field relative to the Eurasian Plate (Wang & Shen, 2020). The red focal sphere illustrates the moment tensor solution for the Jishishan earthquake provided by GCMT, and the gray focal spheres represent the moment tensor solutions for M > 6.5 earthquakes since 1970 as given by GCMT. The red box outlines the area covered in panel (b). In panel (b), the black lines depict active faults in China (Qu et al., 2008); the red focal sphere shows the moment tensor solution for the Jishishan earthquake from USGS and GCMT, while the blue focal sphere indicates moment tensor solutions for M > 6 earthquakes since 1970 from USGS. The red and purple box indicates the coverage of the European Space Agency’s Sentinel-1A ascending and descending tracks, with the red box outlining the area in panel (c). In panel (c), the black segments represent active faults, and the green dots denote a precisely located catalog of aftershocks for the Mw 6.1 Jishishan earthquake, detected using artificial intelligence techniques on continuous waveform data (Zhang et al., 2024). HYF: Haiyuan Fault; RYMF: Riyue Mountain Fault; LJNF: Laji Mountain Northern Fault; LJSF: Laji Mountain Southern Fault; NSF: Nanshan Fault; DLF: Daotanghe-Linxia Fault; EKLF: Eastern Kunlun Fault; Jishishan: Jishishan County.

The northeastern edge of the Tibetan Plateau is a relatively independent active crustal block delineated by three major left-lateral strike-slip fault zones: the Altyn Tagh fault zone trending northeast (NEE), the Qilian Mountain-Haiyuan fault zone trending northwest-northwest (NNW), and the eastern Kunlun fault zone trending nearly east-west (EW) (Li et al., 2013). The GPS velocity field indicates that the current movement characteristics of the northeastern Tibetan Plateau involve lateral compression and crustal shortening directed near northeast (Wang & Shen et al., 2020). The seismic background of this event is associated with the Laqishan fault zone at the northeastern edge of the Tibetan Plateau. The Laqishan fault zone consists of two NE-arching compressional reverse faults: the northern Laqishan fault and the southern Laqishan fault, which can be tectonically interpreted as a compressional structural deformation between the left-lateral strike-slip Xiqinling northern fault trending north-westward (NWW) and the right-lateral strike-slip Riyue Mountain fault trending northwest (NNW) (Li et al., 2014; Zhou et al., 2016). Zhou et al. (2016) conducted a three-dimensional crustal deformation analysis of the western section of the Laqishan fault zone using historical leveling and GPS data, revealing that the structural deformation in this western section, controlled by compressional tectonic movements, continues to occur with a vertical movement rate of approximately 1 ± 0.5 mm/a, indicating that this section is in a state of uplift. Particularly since 2008, the differential movements on either side of the fault have become more pronounced, with an increase in the rate of crustal shortening and a notable left-lateral strike-slip component (Zhuang et al., 2023). Within a 300 km radius of the epicenter of the 2023 Jishishan earthquake, historical seismic events include the 1920 Haiyuan M 7.9 earthquake (Ren et al., 2015), the 1927 Gulang M 8.0 earthquake (Tu et al., 1998; Guo et al., 2020), and the 2022 Menyuan M_w 6.7 earthquake (Yu et al., 2022). Furthermore, based on geological studies of historical earthquakes, trenching results in the Daheijia area, north of the earthquake epicenter, reveal that at least two moderate to strong ancient seismic events have occurred since approximately 3700 years Before Present (BP), leading to deformation of the Yellow River terraces and associated flooding disasters (Xia et al., 2003; Wang et al., 2006; Li et al., 2013). The Daheijia trenches are located about 6.4 km from the Lajia site, suggesting that the rapid successive destruction of the site by earthquakes and floods correlates closely with significant ancient seismic events along the Laojishan fault zone around 3136 ± 51 years BP and the formation of a landslide dam upstream on the Yellow River linked to the destruction of the Lajia culture (Yuan et al., 2003; Wang et al., 2006; Wu et al., 2009). Therefore, studying the Jishishan earthquake can provide important insights into reconstructing the objective reality of prehistoric disasters at Lajia and assessing the future seismic hazards in the Laojishan fault zone region.

Table 1

Source parameters of the 2023 Jishishan M_w6.1 earthquake
Source	Longitude/East (°)	Latitude/ North (°)	D/km	Section Ⅰ/(°)			Section II/(°)			Earthquake magnitude
Source	Longitude/East (°)	Latitude/ North (°)	D/km	Strike	Dip	Slip angle	Strike	Dip	Slip angle	Earthquake magnitude
GCMT	102.81	35.83	18.9	303	52	62	164	46	122	M_w6.1
USGS	102.83	35.74	10.0	333	62	88	156	28	93	M_w5.9
CEA-IEF	102.82	35.74	10.0	293	35	63	145	59	108	M_w6.0
GFZ	102.81	35.74	18.0	331	52	98	137	38	79	M_w6.0
This study	102.77	35.76	11.57	306	59	107	/	/	/	M_w6.1
This study	102.77	35.74	8.44	149	33	111	/	/	/	M_w6.1
Note: GCMT (Global Centroid Moment Tensor) ; USGS (United States Geological Survey); CENC (China Earthquake Networks Center); CEA-IEF (Institute of Geophysics, China Earthquake Administration); GFZ (German Research Centre for Geosciences).

3.1. InSAR Data Processing

The revisit period of the Sentinel-1 satellite is 12 days, providing suitable SAR data for studying the Jishi Mountain earthquake on December 18, 2023. This paper selects ascending track T128 and descending track T135 images that cover the earthquake area, performing differential interferometric processing on pre-earthquake images (October 27, 2023, and December 26, 2023) and post-earthquake images (December 14, 2023, and December 26, 2023). The data parameters are shown in Table 1. ALOS DEM (30×30m resolution) is used to remove phase errors caused by topography (Farr et al., 2007). To improve the signal-to-noise ratio, a multi-look factor with six range looks and one azimuth look is employed for multi-looking processing, reducing noise in the interferometric phase. The Goldstein adaptive filter (Goldstein et al., 1995) is used for filtering the interferometric phase, and the minimum-cost flow algorithm is applied to unwrap the wrapped phase (Werner et al., 2002), masking pixels with coherence below 0.3 to obtain reliable line-of-sight (LOS) surface deformation results. Ground Control Points (GCPs) are selected for orbit refinement and re-leveling, correcting satellite trajectory and phase offsets. A DEM is utilized to estimate and mitigate the atmospheric phase delays related to topography. Finally, the interferogram is geo-coded and projected into the WGS-84 geographic coordinate system, resulting in the LOS co-seismic deformation field for the Jishi Mountain earthquake, as shown in Figs. 2 (a) and (b).

Table 2

Differential interferometric image parameters of ascending and descending orbits
Orbit direction (orbit number)	Imaging date		Polarisation mode	Azimuth of line of sight α/(^°)	Incidence angle of line of sight θ/(^°)	Spatial baseline (m)	Time baseline (d)
Orbit direction (orbit number)	Before earthquake	After earthquake	Polarisation mode	Azimuth of line of sight α/(^°)	Incidence angle of line of sight θ/(^°)	Spatial baseline (m)	Time baseline (d)
Asc(T128)	2023-10-27	2023-12-26	VV	-9.9	41.5	64	12
Des(T135)	2023-12-14	2023-12-26	VV	-169.9	39.4	-117	12

3.2. Analysis of Co-seismic Deformation Characteristics

Figure 2 displays the co-seismic Line of Sight (LOS) deformation field along the ascending and descending tracks from InSAR for the 2023 Jishi Mountain earthquake. The direction towards the satellite's flight path is defined as positive (warm colors), while the direction away from it is considered negative (cool colors). Both ascending and descending tracks show an elliptical deformation area predominantly oriented towards the satellite's motion, with the long axis directed NNW, spanning approximately 18 km in the east-west direction and about 22 km in the north-south direction. The deformation zone is primarily located between the northern and southern fault zones of the Laqi Mountain. The LOS deformation characteristics are consistent for both ascending and descending tracks, predominantly indicating uplift. The maximum LOS displacement for the ascending track is approximately 6 cm, while for the descending track, it reaches about 6.7 m. These deformation features suggest that the fault responsible for the 2023 Jishi Mountain earthquake has a thrust nature, aligning with the focal mechanism solutions reported by agencies such as USGS, GCMT, and GFZ.

A profile line AA' crossing the deformation zone was selected from the InSAR deformation field, and profile diagrams (Figs. 3(a) and 3(b)) were generated. From the deformation profile along AA', it is evident that the profile crosses smoothly over the section where the eastern-dipping (southern Laqi Mountain fault) and western-dipping (northern Laqi Mountain fault) faults intersect, without showing shallow surface loss of coherence due to surface rupture or excessive deformation gradients. This indicates that the fault involved in this earthquake did not rupture to the surface.

This study focuses on inverting the co-seismic slip characteristics on the rupture fault plane of the 2023 Jishishan earthquake, using the reconstructed ascending and descending InSAR co-seismic deformation fields as constraints. First, an optimal geometry for the seismic fault is obtained using a nonlinear inversion method. Next, a linear method is applied to determine the detailed slip distribution characteristics on the rupture fault plane. To minimize the influence of far-field noise on the inversion results and enhance efficiency, a non-uniform sampling method is employed, with a 500 m interval for near-field sampling and a 2 km interval for far-field sampling of the deformation area. After downsampling, the number of ascending track points is 2,847 and the number of descending track points is 2,962 (Lohman et al., 2005). Different research institutions have reported consistent earthquake source mechanisms based on far-field body wave inversion (Table 1). Results from the P-wave first motion polarities suggest that this earthquake may have occurred on either an eastward-dipping NNW-trending thrust fault or a westward-dipping SSE-trending thrust fault. Because the earthquake's source depth was shallow and it did not rupture to the surface, determining the fault dip using InSAR observations is challenging. Therefore, this study uses two sets of fault plane parameters released by GCMT as references for the eastward and westward dipping models. The fault inversion utilizes the SDM program (Wang et al., 2013) and performs inversion tests on the rupture model using a two-step approach, with the basic principles discussed by numerous scholars (Tu et al., 2016; Zhang et al., 2021; Yu et al., 2023), and will not be elaborated further here.

4.1 East-Dipping Seismic Fault Model

Using the first set of fault parameters provided by GCMT (strike 303°, dip 52°, and slip angle 62°) as a reference, the search ranges for the fault's strike, dip, and slip angle during inversion were set to [300°, 330°], [40°, 90°], and [0°, 180°], respectively. Based on the characteristics of the InSAR deformation field (Fig. 2), the search ranges for the fault’s length and width were defined as [0, 25] km and [0, 15] km during the inversion process. A nonlinear search for the geometric parameters of the seismic fault was conducted using an optimized multi-peak particle swarm algorithm (Feng et al., 2013). Under east-dipping conditions, the optimal uniform slip fault parameters obtained are shown in Table 1: fault strike of 306°, dip angle of 59°, and average slip angle of 107°. After determining the geometric reference of the seismic fault, distributed fault slip modeling inversion was performed using SDM software (Wang et al., 2013). To prevent boundary effects during the inversion, the dimensions of the rectangular fault plane (length along strike and width along dip) were adjusted to create a 30 km × 20 km rectangular dislocation model, discretizing the fault plane into 1 km × 1 km rectangular elements. The fault strike and position were fixed during the inversion, allowing the slip angle for each sub-fault to freely vary within the range of [0°, 180°]. Additionally, a smoothing factor was introduced to reduce the influence of instability, and the smoothing factor was searched within the range of [0, 0.1] (with a step size of 0.01). Ultimately, under the constraint of an optimal smoothing factor of 0.06, the fine slip distribution characteristics of the SE-dipping fault model were obtained. Figures 4 (a) and (b) demonstrate the coseismic slip distribution characteristics of the 2023 Jishi Mountain earthquake when the fault was east-dipping. Both figures indicate that the coseismic slip distribution is primarily concentrated at depths of 10 to 18 km, with a maximum slip of approximately 0.37 m and a moment magnitude of M_w 6.0. Figures 5 (a) to (f) present the observed coseismic deformation field, the forward modeling deformation field, and the residuals for the 2023 Jishi Mountain earthquake with the fault dipping eastward. Overall, the east-dipping fault model fits the surface deformation field observed by InSAR well, with fitting accuracies of 93.1% for ascending and 93.2% for descending tracks, corresponding to root mean square residuals of 0.62 cm and 0.64

4.2 Model of the Northwest-Dipping Source Fault

Using the second set of fault parameters provided by GCMT (strike 164°, dip 46°, slip angle 122°) as a reference, the search ranges for the fault strike, dip, and slip angle during the inversion process were set to [0°, 180°], [40°, 90°], and [0°, 180°], respectively. Based on the characteristics of the InSAR deformation field (Fig. 2), the search ranges for the length and width of the fault were set to [0, 25] km and [0, 15] km. A nonlinear search for the geometric parameters of the source fault was conducted using an optimized multi-peak particle swarm algorithm (Feng et al., 2013). The results indicated that under a NW dip, the optimal parameters for a uniformly slipping fault are listed in Table 1, with a fault strike of 149°, a dip of 33°, and an average slip angle of 111°. Similarly, to mitigate the effects of instability factors during inversion, a smoothing factor was introduced, with the search range for the smoothing factor set between [0, 0.1] (with a search step of 0.01). Ultimately, under the constraint of the optimal smoothing factor of 0.08, the detailed slip distribution characteristics for the NW-dipping fault model were obtained. Figures 6 (a) and (b) illustrate the coseismic slip distribution features of the 2023 Jishishan earthquake when the fault is southwest-dipping. Both figures show that the coseismic slip distribution is primarily concentrated at depths between 10 and 20 km, with a maximum slip of approximately 0.39 m and a moment magnitude of Mw 6.0. Figures 7 (a) to (f) display the coseismic observed deformation field, forward modeling deformation field, and residual maps for the 2023 Jishishan earthquake with an east-dipping fault. Overall, the east-dipping fault model fits the InSAR-observed surface deformation field well, with a fitting degree of 92.5% for ascending track observations and 91.7% for descending track observations, corresponding to root mean square residuals of 0.66 cm and 0.67 cm, respectively.

5.1 Discussion on Seismic Structures

Identifying the fault trends and locations of moderateto-strong earthquakes is crucial for understanding the distribution of active faults in the region and assessing seismic hazards. Based on InSAR data inversion results (Figs. 4 and 6), the 2023 Jishishan earthquake is classified as a concealed thrust event, but determining the fault trend solely through goodness of fit and residuals (Figs. 5 and 7) lacks convincing evidence. The two forward modeling results, SE dipping and WE dipping, constructed in this study both adequately explain the deformation characteristics of this earthquake (Figs. 2(a) and 2(b)), with corresponding residual levels comparable to the errors observed in InSAR (Figs. 5 and 7), making it difficult to pinpoint the fault through InSAR modeling. To analyze whether the fault is NE-dipping or SW-dipping, this study utilized aftershock localization results to construct aftershock profiles and projected the inverted NE and SW dipping fault planes onto the aftershock profiles, with results shown in Fig. 8. Analysis of the aftershock profile indicates that the aftershock sequence from the Jishishan earthquake displays a nearly NW-SE alignment in the horizontal distribution (Profile AA′), and the depth profile reveals a NE fault trend. Meanwhile, aftershock clusters with NE dip are primarily concentrated on the hanging wall side of the fault, while the SW-dipping fault plane intersects the densely distributed aftershock clusters. Combining previous methods that use the spatial distribution of fault planes and aftershock clusters to determine the trend of reverse faults (Li et al., 2008; Fan et al., 2019), suggests that it is more reasonable for aftershock clusters to concentrate on the hanging wall side when the fault plane is NE-dipping. Considering regional geological data and field investigation results, it is proposed that the fault responsible for the Jishishan earthquake is a thrust fault belonging to the southern side of the Laqi Mountain southern margin fault.

The blue arrows represent the interseismic GPS velocity field relative to the Eurasian Plate (Wang & Shen, 2020); the red line indicates the east-dipping fault model; the blue line represents the west-dipping fault model; the solid red line is the aftershock profile; and the green dots are the precisely located aftershock catalog for the M_w 6.1 earthquake detected using artificial intelligence methods on continuous waveform data (Zhang et al., 2024). LJNF: Laqishan Northern Fault; LJSF: Lajishan Southern Fault; NSF: Nanshan Fault; DLF: Daotang River-Linxia Fault; Jishishan: Jishishan County.

5.2 Changes in Coulomb Stress

Moderate earthquakes typically induce alterations in the stress field of surrounding areas during seismic rupture, which can activate stress states in nearby fault lines, potentially causing future earthquakes to occur earlier or later (Tanioka et al., 2001; Symithe et al., 2013; Liu et al., 2022). As the largest thrust earthquake recorded in the Lajishan Fault Zone since seismic instruments began monitoring, the 2023 Jishishan earthquake is crucial for assessing the seismic risk posed by active faults in adjacent regions. To analyze the stress impact of this seismic event on neighboring faults, we employed the NE-tilted fault model derived from InSAR inversion as the input model. Using the Coulomb 3.3 software developed by Toda et al., we set the equivalent static friction coefficient at 0.4, the shear modulus at 3×10^10, and the Poisson’s ratio at 0.25 to calculate the static Coulomb stress perturbations caused by the co-seismic rupture of the Jishishan earthquake (Toda S et al., 2005). Based on the geometric distribution and kinematic characteristics of active faults in the study area (Fig. 1, Yuan et al., 2005), we defined the average strike of the northern Lajishan fault zone as 128°, with a dip angle of 50° and a slip angle of 90°, while the southern branch was set at an average strike of 314°, dip angle of 50°, and slip angle of 90°. Additionally, the DLF was characterized with receiving fault parameters of a strike angle of 135°, dip angle of 50°, and slip angle of 90° based on field geological survey data and left-lateral slip features (Yuan et al., 2005). The XLNF was defined with receiving fault parameters of an average strike angle of 300°, dip angle of 70°, and slip angle of 0°. Finally, we calculated the changes in Coulomb stress at depths of 5 km, 10 km, and 15 km. Figure 9 indicates that the mid-section of the eastern branch of the LJNF is exhibiting stress loading conditions at a depth of 10 km, with △CFS ≥ 0.01 MPa. Most segments of the southern section of the eastern branch of the LJSF also show stress loading conditions at depths of 5 km and 10 km. The northwestern segment of the DLF exhibits stress unloading conditions at depths of 5 km, 10 km, and 15 km, with △CFS ≤−0.01 MPa; conversely, the southeastern segment displays stress loading at the same depths, with △CFS ≥ 0.01 MPa. Given that these faults are undergoing stress loading and that tectonic activity is currently high, there is a need for vigilance regarding potential future earthquake hazards.

The M_w 6.1 earthquake in Jishishan County, Gansu Province, which occurred on December 18, 2023, took place within the compressive structural zone of the Laji Mountain, situated between the left-lateral strike-slip Xiqinling Fault and the right-lateral strike-slip Riyue Mountain Fault. This study utilized Sentinel-1A IW ascending and descending track data to construct the co-seismic deformation field for the 2023 Jishishan earthquake, and employed this as a constraint to invert the geometric parameters and slip distribution characteristics of the fault plane using a rectangular slip model based on an elastic half-space. Finally, based on the results of Coulomb stress calculations, we discussed the seismic hazard of faults surrounding the epicenter, leading to the following conclusions:

(1) The co-seismic deformation field observed in both ascending and descending tracks from Sentinel-1A for the M_w 6.1 Jishishan earthquake showed a nearly elliptical pattern of surface uplift deformation. The maximum line-of-sight (LOS) displacements were approximately 8 cm for the ascending track and about 9 cm for the descending track. Considering the spatial distribution characteristics of aftershock profiles, this study leans towards the conclusion that the fault plane involved has a northeast (NE) dip, hypothesizing it to be an inferred concealed branch fault located south of the southern edge of Lajishan Mountain.

(2) The NE-dipping co-seismic slip distribution model indicates that the main shock rupture depth concentrated between 8 to 18 km, with a maximum slip of 0.37 m occurring at a depth of 11.57 km from the surface. The seismic moment released during the co-seismic rupture reached approximately 1.8×10^18 N·m, corresponding to a moment magnitude M_w 6.1.

(3) According to the static Coulomb stress changes, this earthquake resulted in a stress loading state in the mid-segment of the eastern branch of the northern edge of Lajishan Fault, the southern segment of the eastern branch of the southern edge of Lajishan Fault, and the southeastern segment of the Daotang River-Linxia Fault. These faults require close monitoring due to their potential rupture risk.

Acknowledgments: We thank the European Space Agency (ESA) for providing the Sentinel-1A radar satellite imagery data (http://asf.alaska.edu/). Special thanks to Professor Wang Rongjiang from GFZ Germany for providing the SDM package. Some figures were produced using GMT software, and we express our

Availability of data and materials

The data that support the findings of this study are available on request from the corresponding author.

Shuyuan Yu: Article writing & revision. Shubi Zhang: Participation in decision making. Jiaji Luo: Data analysis & visualization. Zhejun Li: Software and financial support. Yuanyuan Yang: Validation. Juan Ding: Analysis and mapping.

Statements & Declarations

The authors declare that they have no know competing finanical interests or personal relationships that could have appeared to influence the work reported in this paper.

Ethics approval and consent to participate

Not applicable

Consent for publication

Not applicable

Funding

This research was supported by the National Natural Science Foundation of China (Grant Nos.41802224), Science for Earthquake Resilience of China Earthquake Administration (Grant Nos. XH23019YC and Nos. XH24021C), Joint Open Fund of Mengcheng National Geophysical Observatory (Grant Nos. MENGO-202306), Open Fund of Wuhan, Gravitation and Solid Earth Tides, National Observation and Research Station (Grant Nos. WHYWZ202209)

Competing Interests

The authors have no relevant financial or non-financial interests to disclose.

Fan XM, Scaringi G, Korup O et al (2019) Earthquake-induced Chains of Geologic Hazards: Patterns, Mechanisms, and Impacts. Rev Geophys 57(2):421–503
Farr TG, Rosen P, Caro E, Crippen R, Duren R, Hensley S et al (2007) Shuttle Radar Topography Mission Reviews Geophys 45:2
Feng WP, Li ZH, Elliott JR et al (2013) The 2011 M_W 6.8 Burma earthquake: fault constraints provided by multiple SAR techniques. Geophys J Int 195(1):650–660
Goldstein RM (1995) Atmospheric limitations to repeat-track radar interferometry. Geophys Res Lett 22(18):2517–2520. 10.1029/95GL02475
Guo Peng (2020) Study on the recurrence behavior and hazards of the Chilly Dragon Ridge Fault in the northern Qilian Mountains. Institute of Geology. China Earthq Adminstration. 10.27489/d.cnki.gzdds.2019.000016
Li Z, Wenqiao L, Qinjian T et al (2013) Preliminary study on ancient earthquakes in the hot spring segment of the Hot Water-Jiuyueshan fault zone on the northeast margin of the Qinghai-Tibet Plateau. Progress Geophys 28(04):1766–1771
Li Zmin, Qinjian LYT et al (2014) Study on the Relationship Between the Ancient Earthquake of Lajishan Fault and the Catastrophic Event of Lajia Site. J Seismol Res 37(S1):109–115
Li ZH, Feng WP, Xu ZH et al (2008) The 1998 M_w 5.7 Zhangbei-Shangyi (China) Earthquake Revisited: A Buried Thrust Fault Revealed with Interferometric Synthetic Aperture Radar[J]. Geochem Geophys Geosyst, 9(4)
Liu Boyan XM, Shi Baoping (2022) Effect of Qinghai Madoi MS7.4 earthquake on Coulomb stress and earthquake probability increment of adjacent faults. Chin J Geophys (in Chinese) 65(2):563–579. 10.6038/cjg2022P0703
Lohman RB, Simons M (2005) Some thoughts on the use of InSAR data to constrain models of surface deformation: Noise structure and data downsampling [J]. Geochemistry, Geophysics, Geosystems, 2005, 6(1): Q01007
Zhang L, Wang LFW, Pu J, Yu D et al (2024) High-resolution earthquake catalog of the 2023 M_w 6.0 Jishishan, China Earthquake. 10.11998/IESDC.SEIS.D03EVE20240001
Okada Y (1985) Surface deformation due to shear and tensile faults in a half-space. Bull Seismol Soc Am 75(4):1135–1154
Ren ZK, Zhang ZQ, Chen T et al (2015) Clustering of Offsets on the Haiyuan Fault and Their Relationship to Paleoearthquakes. Geol Soc Am Bull, : B311551
Symithe SJ, Calais E, Haase JS et al (2013) Coseismic slip distribution of the 2010 M 7.0 Haiti earthquake and resulting stress changes on regional faults. Bull Seismol Soc Am 103(4):2326–2343
Tanioka Y, Satake K (2001) Coseismic slip distribution of the 1946 Nankai earthquake and aseismic slips caused by the earthquake. Earth Planet Space 53(4):235–241. 10.1186/BF03352380
Tu HW, Wang RJ, Diao FQ et al (2016) Sllip model of the 2001 Kunlun Mountain Ms8.1 earthquake by SDM: Joint inversion from GPS and InSAR data. Chin J Geophys 59(6):2103–2112. 10.1002/cjg2.20245
Tu delong, Zhang qisheng, Li zhengyang (1998) Tectonic and active tectonic environments of the 7.0 magnitude earthquake in the Republic. Plateau Earthq Res 10(4):9–15
Wang M, Shen ZK (2020) Present-day Crustal Deformation of Continental China Derived from GPS and Its Tectonic Implications. Journal of Geophysical Research (Solid Earth), 125(2): e2019JB018774
Wang Ping Y, Daoyang LD, Jiang Hanchao (2006) Lanzhou Basin, Yellow River three-level terrace OSL age. National OSL and ESR dating academic discussion. China Association for Cultural Heritage Protection; China Earthquake Administration
Wang R, Diao F, Hoechner A (2013) SDM - A geodetic inversion code incorporating with layered crust structure and curved fault geometry. Paper presented at 2013 EGU General Assembly Conference. Vienna, Austria
Wang M, Shen ZK (2020) Present-Day Crustal Deformation of Continental China Derived From GPS and Its Tectonic Implications. J Geophys Research: Solid Earth 125(2):1–2. 10.1029/2019JB018774
Werner C, Wegmuller U, Strozzi T, Wiesmann A (2002) Processing strategies for phase unwrapping for InSAR applications, Proceedings. EUSAR 2002, Cologne, 4–6 June
Wu Qinglong Z, Peizhen Z, Huiping et al (2009) Ancient earthquake-induced landslide dam failures and abnormal ancient flood disasters at the Lajia site in the upstream area of the Yellow River. Sci China (Series D) 39(8):1148–1159
Xia zhengkai, Zanhong W, Zhao Qingchun (2003) Abnormal flood events and their climatic background around 3500a.BP in the Central Plains region of our country. Sci China Press (Part D) 33(9):881–888
Yang Panxin X, Renwei H, Chaozhong et al (2024) Analysis of the focal mechanism of the 6.2 magnitude earthquake in Jishishan, Gansu in 2023. Earthquake 44(01):153–159
Yu shuyuan, Huang xianliang, Zheng haigang, et al (2023) The coseismic reupture model and stress change of the 2022 Menyuan M_w6.7 earthquake. Seismology Geol 45(1):286–303
Yuan Daoyang L, Xiaolong L, Baichi et al (2003) Preliminary study on ancient earthquakes in the Qinghai Hot Springs - Riyue Mountain Fault Zone. Northwest Seismological J 25(2):136–142
Yuan Daoyang Z, Peizhen L, Zhongsheng et al (2005) A preliminary study on the New activity features of the Lajishan mountain fault zone in Qinhai Province. Earthq Res China, (1):93–102
Zhang YF (2021) The geometric and kinematics of the foreland active thrust faults: insight from geodetic deformation observations. Institute of Geology, China Earthquake Administration
Zhuang WQ, Cui DX, Hao M et al (2023) Geodetic Constraints on Contemporary Three-dimensional Crustal Deformation in the Laji Shan–Jishi Shan Tectonic Belt. Geodesy Geodyn 14(6):589–596
Zhou Lin W, Qingliang L (2016) The Study of Crustal Deformation on Western End of Lajishan Fault Based on GPS and Leveling Data. J Geodesy Geodyn 36(12):1056–1059
Toda S, Stein RS, Richards-Dinger K et al (2005) Forecasting the Evolution of Seismicity in Southern California: Animations Built on Earthquake Stress Transfer. Journal of Geophysical Research: Solid Earth, 110(B5): S21C-2
Zhang GM, Ma HS, Wang H et al (2005) Boundaries between active-tectonic blocks and strong earthquakes in the China mainland. Chinese J. Geophys. (in Chinese), 2005, 48(3):602–610
Zhang L, Wang LFW, Pu J, Yu D et al (2024) High-resolution earthquake catalog of the 2023 M_w 6.0 Jishishan, China Earthquake. 10.11998/IESDC.SEIS.D03EVE20240001

Download PDF

Reviewers agreed at journal
10 Aug, 2024
Reviewers invited by journal
05 Aug, 2024
Editor assigned by journal
05 Aug, 2024
First submitted to journal
23 Jul, 2024

You are reading this latest preprint version

Coulomb Stress Characteristics and Fault Slip Distribution of the 2023 Mw 6.1 Earthquake in Jishishan County (Gansu, China) Based on InSAR Observations

Status:

Version 1

Abstract

Figures

1. Introduction

2. Geological Structure Background and Earthquake Hazard Risk

3. InSAR Data Processing and Analysis

3.1. InSAR Data Processing

3.2. Analysis of Co-seismic Deformation Characteristics

4. Inversion of Earthquake Source Mechanism

4.2 Model of the Northwest-Dipping Source Fault

5 Discussion

5.1 Discussion on Seismic Structures

6 Conclusion

Declarations

References

Status:

Version 1