Seismic structure model construction method and system

Abstract

The invention belongs to the technical field of seismic structure models, and discloses a seismic structure model construction method and system, and the method comprises the steps: constructing a database; constructing a three-dimensional digital elevation model; constructing a three-dimensional geological structure model; constructing an earthquake three-dimensional earthquake structure model; constructing a three-dimensional P-wave velocity structure model; and analyzing a pregnancy and earthquake environment. The three-dimensional seismic geologic model of the Changning seismic region is constructed by taking the Changning seismic region in southern Sichuan as a modeling object and integrating superficial geology, landform (DEM), seismic fine positioning data and main fracture distribution, a deep seismic detection result, a two-dimensional seismic reflection profile, drilling data and the like, the spatial distribution and structure of the three-dimensional seismic geologic model are finely determined, and the three-dimensional seismic geologic model of the Changning seismic region is constructed. Analysis of deep and shallow tectonic deformation characteristics and tectonic styles has important guiding significance for discussing the earthquake-pregnancy environment and evaluating the earthquake risk of the deep and shallow tectonic deformation.

Description

Technical Field

[0001] The present invention belongs to but is not limited to the technical field of earthquake structure models, and in particular relates to a method and system for constructing an earthquake structure model. Background Art

[0002] Since 1970, the overall activity level in the Sichuan Basin has been low, but the seismic activity has shown obvious spatial heterogeneity. In addition to the earthquakes that occurred in Zili and Yanting in recent years, most earthquakes occurred in Qianwei, Weiyuan, Zigong, Longchang, Changning, Yunlian in southern Sichuan and Rongchang in Chongqing, showing a significant cluster distribution. Although the intensity of earthquakes has not increased significantly, the frequency of earthquakes has shown a significant increase year by year, and in recent years, there has been a sharp increase.

[0003] By 2017, the Changning area in southern Sichuan had experienced a number of moderate-to-strong earthquakes with a magnitude of Ms ≥ 4.7, including the 4.9-magnitude Yunlian earthquake on January 28, 2017, the 5.7-magnitude Xingwen earthquake on December 16, 2018, the 5.3-magnitude Gong earthquake on January 3, 2019, the 6.0-magnitude Changning earthquake on June 17, 2019, and the 5.6-magnitude Gong earthquake on July 4, 2019. The region has a complex geological structure and active movements, with frequent earthquakes. Wang Shiyuan et al. (2017) speculated that the Leyi anticline was the breeding structure of the Yunlian earthquake, and the distribution of aftershocks was restricted by the Zazi'ao fault on the east side. Lei et al. (2019) believed that the Xingwen and Gongxian earthquakes were caused by the reactivation of pre-existing hidden faults caused by shale gas water injection and fracturing. In the early stage, some scholars had paid attention to the phenomenon of earthquakes induced by industrial water injection activities in the Changning salt mine (Ruan Xiang et al., 2008), and found that pressurized water injection in water injection wells had a significant regulatory effect on earthquake activity (Zhang Zhiwei et al., 2012). Regarding the seismogenic structure of the Changning 6.0 earthquake, He Dengfa et al. (2019) believed that the Changning anticline was a large basement fault-turned fold anticline. The earthquake currently mainly occurred on the southern wing of the anticline, which was a natural earthquake formed by the activity of the slope of the footwall of the basement fault. Yi Guixi et al. (2019) inferred that the occurrence of the Changning Ms6.0 earthquake sequence was related to the Baixiangyan-Shizitan anticline and Shuanghechang folds and their associated fault activities in the Changning-Shuanghe compound anticline, and triggered the associated fault activities of the Baixiangyan-Shizitan anticline to produce several consecutive magnitude 5 earthquakes. Chang Zufeng et al. (2020) believed that the regional NW-trending longitudinal joints were structurally strengthened, connected, and further ruptured under the action of the NE-trending paleo-tectonic stress field and rotational stress field in the Shuanghe anticline under the overpressure environment, which was superimposed on the NE-trending paleo-tectonic stress field and the rotational stress field, which was the cause of the Changning Ms6.0 earthquake. At present, the research on the seismic tectonic background of the area is not in-depth, the geological structure is complex, and secondary folds and faults are developed. Therefore, it is urgent to gradually establish a three-dimensional geological structure model of the Changning earthquake zone to further explore the relationship between earthquakes and active faults, old faults and new faults, and faults and folds.

[0004] The level of seismic activity in the Sichuan Basin has been low since 1970, but there is obvious unevenness in spatial distribution, especially in certain specific areas in southern Sichuan, where seismic activity shows the characteristics of clustering. Although the intensity of earthquakes has not increased significantly, the frequency of earthquakes has increased year by year, especially in recent years. When studying this phenomenon, the existing technology faces the following major technical problems:

[0005] 1) Complex geological structure: The geological structure of Changning in southern Sichuan is extremely complex, with a large number of secondary folds and faults. The existing geological structure model cannot accurately reflect these complex geological structures, resulting in a lack of accurate geological background support when predicting and analyzing earthquake activities. In particular, different scholars have different interpretations of earthquake structures. For example, there are many different views on the seismogenic structure of the Changning 6.0 earthquake, reflecting that the understanding of geological structure is not deep enough.

[0006] 2) Uncertainty in earthquake induction mechanisms: In recent years, the phenomenon of earthquakes induced by industrial activities such as shale gas water injection fracturing and salt mine water injection has increased. Existing technologies make it difficult to clearly distinguish the relationship between natural earthquakes and induced earthquakes, and there is a lack of systematic analysis and model support when assessing the impact of industrial activities on seismic activity. Different scholars have different interpretations of the induction mechanism of the same earthquake event, reflecting the complexity and challenges of research in this field.

[0007] 3) Lack of 3D geological structure model: At present, the research on the 3D geological structure model of Changning area in southern Sichuan is not in-depth and systematic enough. Due to the lack of detailed 3D model, it is difficult to fully understand the seismic tectonic background and fault activity patterns in the area. This limits the accuracy and effectiveness of earthquake prediction and disaster prevention.

[0008] 4) Insufficient research on the relationship between faults and folds: In the geological structure of Changning area in southern Sichuan, the relationship between faults and folds is complex. At present, the research on these relationships is not in-depth, especially how the interaction mechanism manifests itself during earthquakes. The existing technology lacks comprehensive theoretical support and actual data verification when exploring these relationships.

[0009] The existence of these technical problems has seriously affected the understanding and prediction of seismic activity in the southern Sichuan Basin. It is urgent to solve the existing technical bottlenecks and enhance the ability to prevent and reduce earthquake disasters by establishing a detailed three-dimensional geological structure model and conducting in-depth mechanism research. Summary of the invention

[0010] In view of the problems existing in the prior art, the present invention provides a method for constructing an earthquake structure model.

[0011] The present invention is achieved by a method for constructing an earthquake tectonic model, the method comprising:

[0012] S1: Database construction, collecting information from multiple data sources, including earthquake catalog data, geological maps, drilling data, seismic waveform data, seismic profiles and geological exploration data, integrating and preprocessing the data, and establishing a unified geological and seismic database;

[0013] S2: Construction of three-dimensional digital elevation model, using remote sensing images, lidar and other technologies to obtain high-resolution terrain data, generate and calibrate digital elevation model;

[0014] S3: Construction of 3D geological structure model: Based on the results of geological profile analysis, a 3D geological structure model is constructed using professional 3D geological modeling software, and the accuracy of the model is verified by comparing it with actual geological exploration data;

[0015] S4: Construction of a three-dimensional seismic tectonic model. Based on the focal mechanism analysis and source distribution modeling, the source information of earthquake events is superimposed on the three-dimensional geological structure model to construct a three-dimensional seismic tectonic model, and the fault activity is analyzed in combination with historical earthquake data and fault geometry.

[0016] S5: Construction of a three-dimensional P-wave velocity structure model. Collect seismic wave velocity measurement data and seismic tomography results, use seismic tomography technology to construct a three-dimensional P-wave velocity structure model, and calibrate the model with travel time data from actual earthquake records.

[0017] S6: Analysis of the seismic environment: using the three-dimensional seismic tectonic model and the P-wave velocity structure model to analyze the distribution of the geostress field in the study area, assess the seismic hazard, identify potential sources of earthquake hazards, and develop earthquake prediction plans and disaster prevention and mitigation measures.

[0018] In step S1, the collected data is subjected to denoising, data format conversion and missing data filling to ensure the quality and consistency of the data.

[0019] Among them, in step S2, high-resolution terrain data is obtained by using laser radar, and the generated digital elevation model can accurately reflect the ups and downs of the terrain, and the model is corrected to eliminate errors in the data collection process.

[0020] In step S5, the three-dimensional P-wave velocity structure model is corrected by the travel time data of the actual seismic record to improve the accuracy of the model and make it accurately reflect the P-wave velocity variation characteristics of different strata. Further, the S1 specifically includes:

[0021] Using geological profile data and comprehensive stratigraphic interpretation data as the main geological modeling data, and using borehole and seismic profile data as constraints, the quality control of the three-dimensional spatial position and geometric relationship of strata and faults is carried out; using earthquake relocation data to display the three-dimensional spatial distribution characteristics of earthquakes, and combining focal mechanism solution data to construct an initial seismogenic fault model; using crustal velocity structure data to establish a three-dimensional velocity structure model to support the rationality of the construction of the three-dimensional geological structure model and the comprehensive interpretation of the seismogenic structure characteristics;

[0022] Since the data sources, types and formats of multi-source data fusion modeling are different, in order to integrate these data, the data format, scale, coordinate system and projection parameters must be unified first, so as to establish the original data database in the Gocad software.

[0023] Furthermore, S2 specifically includes: realizing digital simulation of ground terrain (i.e., digital expression of terrain surface morphology) through limited terrain elevation data, which can more objectively display the geomorphic features of the study area, and combining DEM and GIS spatial analysis technology for geomorphic analysis, which can better obtain geomorphic information of the study area.

[0024] Further, the S3 specifically includes:

[0025] (1) 3D stratigraphic model analysis;

[0026] (2) Fault model analysis;

[0027] (3) Geological body model analysis.

[0028] Further, the S4 specifically includes:

[0029] (1) Analysis of characteristics of three-dimensional seismic sequences;

[0030] (2) Analysis of three-dimensional earthquake fault models;

[0031] (3) Comprehensive analysis of seismogenic structures.

[0032] Further, the S5 specifically includes:

[0033] (1) Construction of a three-dimensional crustal velocity structure model;

[0034] (2) Analysis of three-dimensional P-wave velocity structure model.

[0035] Another object of the present invention is to provide a seismic tectonic model construction system based on the seismic tectonic model construction method, the system specifically comprising:

[0036] Database construction module, used for database construction;

[0037] A model building module is used to build a three-dimensional digital elevation model, a three-dimensional geological structure model, a three-dimensional earthquake structure model, and a three-dimensional P-wave velocity structure model respectively;

[0038] The seismic environment analysis module is used for seismic environment analysis.

[0039] Another object of the present invention is to provide a computer device, characterized in that the computer device includes a memory and a processor, the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the earthquake structure model construction method.

[0040] Another object of the present invention is to provide a computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the processor executes the steps of the earthquake structure model building method.

[0041] Another object of the present invention is to provide an information data processing terminal, which is used to implement the earthquake structure model building system.

[0042] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0043] First, the earthquake tectonic model, also known as the seismogenic tectonic model, is the basis for understanding the mechanism of earthquake occurrence and the assessment of the maximum potential earthquake, and is also the intermediate bridge between basic data and earthquake risk assessment. The present invention takes the Changning earthquake zone in southern Sichuan as the modeling object, integrates the superficial geology, topography and geomorphology (DEM), earthquake precise positioning data and the distribution of major faults, deep earthquake detection results, two-dimensional seismic reflection profiles, drilling data, etc., to construct a three-dimensional earthquake geological model of the Changning earthquake zone, finely determine its spatial distribution and structure, analyze the deformation characteristics and structural styles of deep and shallow structures, which has important guiding significance for exploring its seismogenic environment and earthquake hazard assessment.

[0044] Second, in the existing seismic tectonic model construction technology, data acquisition and integration are multi-source heterogeneous, making it difficult to form a unified geological structure information database. At the same time, traditional models are usually based on two-dimensional analysis and cannot accurately reflect the complexity of fault distribution, crustal structure and seismic wave propagation paths in three-dimensional space. In addition, the analysis of earthquake-prone environments mainly relies on expert experience, lacks dynamic numerical simulation and precise mechanical analysis, and is difficult to achieve quantitative assessment of earthquake source locations and earthquake risks. These technical bottlenecks significantly limit the application value of seismic tectonic models in the field of disaster prevention and mitigation.

[0045] The present invention solves the problem of multi-source data integration by constructing a standardized earthquake structure database, and significantly improves the data quality and the reliability of the modeling basis. Combined with the three-dimensional digital elevation model and the three-dimensional geological structure model, the present invention can accurately depict the spatial distribution of faults and rock layers, solving the problem that the traditional two-dimensional model cannot fully reflect the complexity of earthquake structures. By introducing the P-wave velocity structure model and dynamic mechanical analysis, the present invention breaks through the bottleneck of the existing technology for quantitative analysis of the earthquake-prone environment, and provides an accurate description of the seismic wave propagation path and the mechanical characteristics of the source.

[0046] The present invention has achieved a number of significant technological advances in industrial applications: (1) Using three-dimensional modeling technology, complex geological structures and seismic wave propagation characteristics are visualized, which improves the intuitiveness and scientificity of the model; (2) Based on the P-wave velocity structure model, the accuracy of describing the underground medium characteristics and seismic wave propagation path is improved, providing a reliable basis for earthquake source location; (3) Combined with the dynamic seismogenic environment analysis, the quantitative assessment of fault activity characteristics and regional earthquake risks is achieved, significantly improving the accuracy of earthquake risk prediction; (4) A set of standardized and systematic earthquake structure model construction methods is formed, providing technical support for earthquake monitoring and geological disaster prevention and control.

[0047] The present invention provides a reliable tool for earthquake monitoring and risk assessment through an accurate and efficient earthquake structure model construction method. Its technical advantages in data processing, model accuracy and seismic environment analysis have greatly improved earthquake risk prediction and disaster prevention and mitigation capabilities. At the same time, the method has a wide range of applicability and can be applied not only to the field of earthquake monitoring, but also to related industries such as energy development and underground engineering. It provides technical support for the research and safety management of complex geological environments and has important industrial value and application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a flow chart of a method for constructing an earthquake structure model provided by an embodiment of the present invention;

[0049] Figure 2 is a distribution map of earthquake epicenters in the Sichuan Basin since 1970 provided by an embodiment of the present invention;

[0050] Figure 3 The MT and NT diagrams of earthquake activity in the Sichuan Basin since 1970 provided by the embodiment of the present invention;

[0051] Figure 4 is a distribution map of the epicenters and aftershocks of moderate-strong earthquakes in the study area provided by an embodiment of the present invention;

[0052] Figure 5 It is the geological structure overview of the study area provided by the embodiment of the present invention (the brown line is the geological section);

[0053] Figure 6 is a schematic diagram of modeling data provided by an embodiment of the present invention;

[0054] Figure 7 The three-dimensional digital elevation model (vertically stretched 3 times) provided in an embodiment of the present invention;

[0055] Figure 8 The three-dimensional stratigraphic model of Changning area provided by the embodiment of the present invention (vertically stretched 3 times);

[0056] Fig. 9 The Changning-Shuanghe large anticline structural fault model (longitudinal stretching 1.5 times) provided in an embodiment of the present invention;

[0057] Fig.10 The three-dimensional geological model of Changning area provided by the embodiment of the present invention;

[0058] Fig.11 The three-dimensional spatial distribution of the epicenters of the Changning earthquake sequence provided by the embodiment of the present invention is as follows: (a) side view; (b) top view; (c) ML≥3.0; (d) ML≥4.0;

[0059] Fig.12 It is the time evolution characteristics of the Changning earthquake sequence provided by the embodiment of the present invention;

[0060] Fig.13 This is the initial model of the seismogenic fault of the Changning earthquake sequence provided by an embodiment of the present invention: (a) a bird's-eye view; (b) a front view;

[0061] Fig.14 The seismogenic structure model of the Changning earthquake provided by the embodiment of the present invention;

[0062] Fig.15 is a three-dimensional P-wave velocity structure model provided by an embodiment of the present invention;

[0063] Fig.16 It is a transverse slice diagram of a three-dimensional P-wave velocity structure model provided by an embodiment of the present invention;

[0064] Fig.17 A shallow three-dimensional geological model and a three-dimensional P-wave velocity structure diagram (h≥1km) provided by an embodiment of the present invention;

[0065] Fig.18 It is a three-dimensional P-wave velocity anomaly extraction provided by an embodiment of the present invention;

[0066] Fig.19 It is a schematic diagram of the Sichuan Basin earthquake structure model provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0067] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0068] like Figure 1 As shown, an embodiment of the present invention provides a method for constructing an earthquake structure model, the method comprising:

[0069] S1: Construction of database;

[0070] S2: Construction of three-dimensional digital elevation model;

[0071] S3: Construction of three-dimensional geological structure model;

[0072] S4: Construction of a 3D seismotectonic model of the earthquake;

[0073] S5: Construction of three-dimensional P-wave velocity structure model;

[0074] S6: Analysis of seismic environment.

[0075] The present invention firstly establishes a unified earthquake structure database by collecting multi-source earthquake data, geological exploration data and three-dimensional terrain data. The database integrates multi-dimensional data such as earthquake source distribution, fault information, surface elevation, etc. After classification, formatting and preprocessing, a standardized data structure is formed to provide complete and reliable basic data support for subsequent model construction. This stage ensures the accuracy and consistency of the data, laying the foundation for building an accurate earthquake structure model.

[0076] In the elevation model construction stage, terrain data is used to generate a three-dimensional digital elevation model to accurately describe the spatial distribution of the surface terrain. Subsequently, by integrating geological exploration data, a three-dimensional geological structure model is constructed to refine the three-dimensional morphology and spatial distribution of faults, rock layers and geological structures. This model, combined with seismic activity records, truly reflects the details of the geological structure and provides geological background support for subsequent seismic structure analysis.

[0077] In the process of constructing the three-dimensional earthquake structure model, the earthquake activity data, fault distribution and three-dimensional geological structure are combined to generate a seismic structure model to capture the spatial characteristics and correlation patterns of fault activity. By collecting records of seismic wave propagation, the three-dimensional P-wave velocity structure model is further constructed using the inversion algorithm. This model can reflect the velocity distribution and heterogeneity of the underground medium, accurately describe the propagation path of seismic waves, and provide a dynamic basis for the analysis of the seismogenic environment.

[0078] In the stage of earthquake-pregnancy environment analysis, the geomechanical environment, stress distribution and fault activity characteristics of the source area are comprehensively analyzed by combining the three-dimensional seismic tectonic model and the P-wave velocity structure model. By simulating the stress accumulation and release process in the source area, the potential earthquake risk in the area is evaluated, and the possible epicenter location and magnitude range are predicted. This method realizes the whole process from data collection to risk assessment, provides a scientific earthquake prediction and disaster prevention decision support tool, and is widely used in earthquake monitoring, geological disaster early warning and other fields.

[0079] An embodiment of the present invention provides a method for constructing an earthquake tectonic model, comprising the following steps:

[0080] S1: Database construction

[0081] Data collection: Collect information from a variety of data sources, including earthquake catalog data, geological maps, borehole data, seismic waveform data, seismic profiles, and geological exploration data.

[0082] Data integration: Integrate information from different data sources to establish a unified geological and seismic database. The database should include information on faults, folds, strata, and detailed records of historical earthquake events.

[0083] Data preprocessing: Preprocess the collected data, such as denoising, data format conversion, missing data filling, etc., to ensure the quality and consistency of the data.

[0084] S2: Construction of 3D digital elevation model

[0085] Data source: High-resolution terrain data is obtained using remote sensing images, LiDAR and other technologies.

[0086] Digital elevation model (DEM) generation: The acquired terrain data is processed to generate a digital elevation model. DEM contains the elevation information of the surface and can accurately reflect the ups and downs of the terrain.

[0087] Data correction: Correct the DEM to eliminate errors in the data collection process and ensure the accuracy of the model.

[0088] S3: Construction of 3D geological structure model

[0089] Geological profile analysis: Using borehole data, geological maps and seismic profiles, geological profile analysis is conducted on the study area to determine the spatial distribution of major strata and the location of faults.

[0090] Model construction: Based on the results of geological profile analysis, a three-dimensional geological structure model is constructed using professional three-dimensional geological modeling software (such as GOCAD, Petrel, etc.). The model should accurately reflect the spatial distribution of the strata and the geometric morphology of the faults.

[0091] Model verification: By comparing with actual geological exploration data, the accuracy of the three-dimensional geological structure model is verified and necessary corrections are made.

[0092] S4: Construction of 3D seismic tectonic model

[0093] Focal mechanism analysis: Use seismic waveform data and focal mechanism solutions to determine the focal parameters of major earthquake events in the study area (such as epicenter location, focal depth, and fault plane solutions).

[0094] Source distribution modeling: On the basis of the three-dimensional geological structure model, the source information of the earthquake event is superimposed to construct a three-dimensional earthquake structure model. The model should reflect the spatial distribution of earthquake events and the characteristics of the source mechanism.

[0095] Fault activity analysis: Combine historical earthquake data and fault geometry to analyze fault activity and earthquake recurrence cycles.

[0096] S5: Construction of a 3D P-wave velocity structure model

[0097] Velocity data collection: Collect seismic wave velocity measurement data and seismic tomography results to obtain P-wave velocity information of the strata in the study area.

[0098] Velocity model construction: Using seismic tomography technology, a three-dimensional P-wave velocity structure model is constructed based on the collected velocity data. The model should reflect the P-wave velocity variation characteristics of different strata.

[0099] Model correction: The three-dimensional P-wave velocity structure model is corrected through the travel time data of actual earthquake records to improve the accuracy of the model.

[0100] S6: Analysis of seismic environment

[0101] Stress field analysis: Utilize the three-dimensional seismic tectonic model and P-wave velocity structure model to analyze the distribution of the geostress field in the study area and determine the main stress concentration areas.

[0102] Earthquake hazard assessment: Combine fault activity and stress field distribution to assess the seismic hazard of the study area and identify potential sources of earthquake hazards.

[0103] Earthquake prediction and disaster prevention: Based on the results of earthquake-prone environment analysis, formulate earthquake prediction plans and disaster prevention and mitigation measures to improve earthquake early warning and disaster prevention capabilities.

[0104] Through the above steps, a three-dimensional earthquake tectonic model of the southern Sichuan Basin can be systematically and comprehensively constructed, providing a scientific basis for in-depth research on the laws of earthquake activity and the formulation of disaster prevention and mitigation measures.

[0105] The research area of ​​the present invention is located at the junction of Sichuan, Yunnan and Guizhou, and the structure is located at the junction of the southern Sichuan low-lying fold belt and the Daliangshan-Loushan fault fold belt in the Sichuan Basin (Tong Chongguang, 1992; Guo Zhengwu et al., 1996, He Dengfa et al., 1992). In addition to the lack of Devonian and Carboniferous systems, the Cambrian-Jurassic systems are widely deposited in the area, with a thickness of more than 10,000 meters. There is no obvious angular unconformity in the strata of each system. The main fold structures in the area are the Changning-Shuanghe compound large anticline and the Jianwu syncline.

[0106] The Changning-Shuanghe compound large anticline runs northwest through Gongxian to Gaoxian area and southeast to Xuyong area. It is a single box-shaped lace-shaped hypertrophic anticline with steep north wing and gentle south wing. The main axis is northwest-southeast. The north wing and the west end are steep (40-60°), and the south wing and the east end are gentle. Secondary folds and faults are developed in the anticline, and there is a superposition of different structural features, so there are many high points, many faults, many nose-shaped structures, the axis is not connected, and the direction of the secondary structural lines is different. The Cambrian and Silurian strata are exposed in the core of the Changning anticline, and the Permian-Triassic strata are exposed on both wings.

[0107] The Jianwu syncline is distributed from Jianwu, Xingwen County to Shangluochang, Gong County. It is a box-shaped syncline with two wings that are approximately symmetrical. The two wings tend to be roughly due north by east and due south by west. To the west, the Leikoupo Formation rises at 80∠12° near Shangluochang, Gong County. The exposed strata in the axis are the Shaximiao Formation of the Middle Jurassic System. The axis is nearly east-west, the strata are relatively gentle, and the dip angle is between 5 and 10°.

[0108] Table 1 Brief list of stratigraphic sequences in the study area

[0109]

[0110] The collection of modeling data is not just a simple collection and summary. It is also necessary to judge whether it is suitable for the current modeling work based on the data quality and the specific requirements of the modeling scope and accuracy (Li Cheng, 2019). Figure 6 As shown in Table 2, the geological profile data and the comprehensive stratigraphic interpretation data are used as the main geological modeling data, and the drilling and seismic profile data are used as constraints to control the quality of the three-dimensional spatial position and geometric relationship of the strata and faults. The earthquake relocation data are used to display the three-dimensional spatial distribution characteristics of earthquakes, and the initial seismogenic fault model is constructed in conjunction with the focal mechanism solution data. The three-dimensional velocity structure model is established through the crust velocity structure data to support the rationality of the construction of the three-dimensional geological structure model and the comprehensive interpretation of the seismogenic structure characteristics.

[0111] Table 2 Modeling data list

[0112]

[0113] Since the data sources, types and formats of multi-source data fusion modeling are different, the data format, scale, coordinate system and projection parameters must be unified to integrate these data, so as to establish the original data database in Gocad software. This geological modeling established two scales of three-dimensional geological models according to the size of the region and the accuracy of the model. The stratigraphic modeling units are shown in Table 3.

[0114] Table 3 List of stratigraphic modeling units

[0115]

[0116]

[0117] Digital Elevation Model (DEM) is a digital simulation of the ground terrain (i.e., a digital expression of the terrain surface morphology) using limited terrain elevation data. The three-dimensional digital elevation model can more objectively display the geomorphic features of the study area. At the same time, combining DEM and GIS spatial analysis technology for geomorphic analysis can better obtain geomorphic information of the study area.

[0118] The study area has an altitude of 302-1786 meters, and the overall landform is low mountain-hill-river valley ( Figure 7 ).

[0119] The stratigraphic development in Changning area in southern Sichuan is relatively complete. From top to bottom, the Quaternary, Cretaceous, Jurassic, Triassic, Permian, Silurian, Ordovician, Cambrian and Sinian strata are developed in sequence, while the Devonian, Carboniferous, Paleogene and Neogene are missing. The stratigraphic thickness exceeds 9 km. Figure 8 The Quaternary strata in the region are only scattered in the Changning anticline and Jianwu syncline, the Cretaceous strata are only developed in the adjacent syncline, the Jurassic strata are developed in the adjacent syncline, the Fujiang syncline, the Luochang syncline, the Jianwu syncline and the Changguansi-Xuyong syncline, the Triassic strata are denuded in the Baixiangyan-Shizitan anticline, the Changning anticline, the Yunlian anticline and the Xunsichang anticline, the Permian-Ordovician strata are denuded from the Baixiangyan-Shizitan anticline to the Changning anticline, and the rest of the strata are continuously developed throughout the region. Among them, the older strata are exposed in the core of the Changning anticline, and the burial depth of the strata is generally deep in the north and shallow in the south. The strata of each age are in conformity or parallel unconformity contact, and no angular unconformity is developed.

[0120] The Changning-Shuanghe anticline structure exposed fault ( Fig. 9) Mainly include: 1. Dafenba reverse fault, the fault is broken in the Permian and Triassic strata, with a dip of N and a dip of 77°. Gongxian normal fault is distributed in the north of Gongxian, with a strike of nearly SN, a dip of E, and a dip of about 70°. It is broken in the Silurian and Permian strata. 2. Gongxian normal fault is distributed in the north of Gongxian, with a strike of nearly SN, a dip of E, and a dip of about 70°. It is broken in the Silurian and Permian strata. 3. The overall strike of Dadiwan fault is NEE, with a dip of NW and a dip of about 51-79°. The fault is mainly broken in the Lower Paleozoic strata, with a thrust nature and a vertical fault throw of more than 300m. 4. The strike of Wafangtou fault is NEE, with a dip of SE and a dip of nearly vertical; 5. Dafoya fault is NW-oriented, with a dip of NE and a dip of about 60°.

[0121] The Changning-Shuanghe anticline is one of the main structures in the Changning area. Fig.10 ), with a steep northeast wing and a gentle southwest wing, presenting an asymmetric single box type, long axis anticline, composed of fold structures such as Tenglong anticline, Baixiangyan-Shizitan anticline, Shuanghechang anticline, Meizi'ao anticline, and Changning anticline, with associated faults of different scales and very different geometric structures. The Baixiangyan-Shizitan anticline is NE in the west and nearly EW in the east. The core strata are Cambrian, and the two wings are monocline; the associated faults exposed on the surface of the fold are relatively sporadic, and the main faults include the Dafenba Fault and the Gongxian Fault. The Shuanghechang fold is located in the core of the Changning-Shuanghe anticline. The core strata are Cambrian Loushanguan Group limestones, and the strata on the two wings are Silurian and Permian. Its axis is slightly arc-shaped protruding to the NW. The dip angle of the strata on the west wing is about 27°, and the dip angle of the strata on the east wing is 55°, forming an asymmetric anticline. The faults exposed on the surface of this fold structure are relatively complex, and the main faults include the Dadiwan Fault, the Wafangtou Fault, the Dafoya Fault, etc.

[0122] The Jianwu syncline is also one of the main tectonic units in the Changning area ( Fig.10 ), with a dip angle of 10-25° on the north wing and 15-20° on the south wing, and an EW axis. The eastern end rises to the north of Dashanping, and its strata gradually change to SN trend, forming the western wing of the Dayuanzi nose anticline, which is an asymmetric syncline. The Jurassic is exposed in the core of the syncline, and the strata on the two wings are Jurassic and Triassic.

[0123] Using the relocated Changning Ms6.0 earthquake sequence, 622 ML≥1.5 earthquakes from June 17 to July 4, 2019 were selected to analyze the distribution of aftershock swarms in three-dimensional space. Fig.11 a,b show that the aftershock zone is generally NW-SE, about 23km long and 5km wide, with a focal depth of 0-10km and an average depth of 4.086km. The Changning Ms6.0 earthquake is located at the southeast end of the aftershock zone. Most of the aftershocks in this sequence are located to the northwest of the Changning Ms6.0 earthquake, and all aftershocks above Ms3.0 are located to the northwest of the Changning Ms6.0 earthquake ( Fig.11c), showing a unilateral rupture. The Ms4.0 and above earthquakes in this sequence are concentrated in the range of 4-8 km, and about 6 km is the dominant focal depth of the Ms4.0 and above earthquakes in this sequence. The focal depths of the Ms4.0 and below earthquakes in this sequence are mostly above 6 km, accounting for 87.8%. In the southeastern section of the sequence, aftershocks are relatively sparse, while in the northwest section, they are relatively dense, and the focal depth is deep in the northwest and shallow in the southeast. The earthquake distribution characteristics have multiple faults involved in the activity.

[0124] Time-space relationship of 622 Changning earthquake sequences with ML ≥ 1.5 from June 17 to July 4, 2019 ( Fig.12 ) from the perspective of the earthquake sequence, the earthquake sequence is divided into two branches, the east and the west, which develop in different directions. As time goes by, the aftershock sequence of the western branch develops to the northwest, and develops a secondary branch in the northeast direction in the later stage of the sequence. From the horizontal view ( Fig.12 ) It can be seen that the focal depth of the western branch earthquake swarm was first concentrated in the range of 2-6 km, then developed in the shallow and deep directions, and finally filled the entire area of ​​0-10 km. The eastern branch aftershock swarm developed in the southeast direction with the passage of time. The focal depth was first limited to the maximum depth of the swarm by Changning Ms6.0 and its aftershocks, and then gradually filled the entire area of ​​0-7 km within this range. Fig.12 ), at 22:55:44.0 on June 17, 2019, the Ms6.0 earthquake in Changning occurred, followed by the Ms5.1 earthquake in Gongxian at 23:36:1.9 on the same day. The interval between the two earthquakes was only 41 minutes, and they were located below the southeast end of the east and west branches of the Changning earthquake sequence. The east and west aftershock swarms developed almost simultaneously along their dominant distribution directions. The present invention believes that the west branch aftershock swarm was formed after the Changning Ms6.0 earthquake triggered the Gongxian 5.1 earthquake, and the seismogenic structures of the east and west aftershock swarms should belong to different underground structures.

[0125] The construction of a three-dimensional seismogenic fault model is of great significance for analyzing the seismogenic structure of earthquakes, exploring the relationship between earthquakes and faults, and determining the subsequent earthquake trend. Based on the relocation results of small earthquakes in Changning area and the focal mechanism solution of Changning area, the present invention simulates the seismogenic fault of the Changning earthquake sequence in three dimensions and gives an initial three-dimensional model of the seismogenic fault.

[0126] The seismogenic structure geometry of the Changning earthquake sequence is relatively complex. The sequence activity is not caused by a single fault movement, but is the result of multiple faults participating in the sequence activity. This paper constructs a three-dimensional seismogenic fault model based on the focal mechanism solution and the spatial and temporal distribution characteristics of the Changning earthquake sequence. Fig.13 As shown, F1-F4 are the faults that gen- erated the aftershock swarm in the east branch, and F5-F7 are the faults that gen-erated the aftershock swarm in the west branch.

[0127] According to the three-dimensional structure of the faults that caused the Changning earthquake sequence, F1 is the main fault of the eastern branch earthquake group. The fault strikes NW as a whole and dips to SW. The fault strikes changed on the east and west sides of the Changning Ms5.3 earthquake on June 18, with the strikes on the west side being about 330° and the east side being about 315°. The fault is curved in an arc shape. The Changning Ms6.0 on June 17, 2019, Changning Ms4.5 on June 18, Changning Ms5.3 on June 18, and Changning Ms4.8 on July 3 all occurred on the F1 fault. According to the focal mechanism solution of the Changning earthquake sequence calculated by Yi Guixi and others, the Changning Ms6.0 earthquake on June 17 was a thrust and strike-slip type, the Changning Ms4.5 earthquake on June 18, the Changning Ms5.3 earthquake on June 18, and the Changning Ms4.8 earthquake on July 3 were all thrust types. Therefore, it is judged that the F1 fault is a reverse fault, and its southeast end has a strike-slip nature.

[0128] F5 is the main section of the west branch aftershock swarm. Because the focal mechanism of the west branch swarm is relatively scattered, F5 is constructed using the dominant distribution of the west branch aftershocks. It represents the spatial geometric distribution of the dominant faults of the aftershock sequence. In fact, the west branch aftershock swarm should have multiple faults participating in the earthquake activity. According to the dominant distribution characteristics of the aftershock sequence and the focal mechanism solution, some branch faults and secondary faults are also established. In general, the faults that cause the Changning aftershock sequence are mostly hidden faults, with a relatively vertical dip angle and a main NW strike, which is consistent with the NW axis of the Changning-Shuanghe anticline structure.

[0129] The seismogenic tectonic geometry of the Changning earthquake sequence is relatively complex. The sequence activity does not originate from a single fault movement, but is the result of multiple faults participating in the sequence activity.

[0130] According to the distribution characteristics of the Changning earthquake sequence, it can be divided into two groups of structures: the Baixiangyan-Shizitan anticline and the Shuanghechang fold. Magnetotelluric inversion and drilling data reveal that the Shuanghechang fold is formed by the mud-peel structure. The mud-peel structure is controlled by the Wafangtou Fault, the Dadiwan Fault and other hidden faults, and is cross-cut by the Dafoya Fault, extending downward to the Sinian System. The seismogenic fault of the Changning earthquake is close to the Dafoya Fault and its strike is consistent with that of the Dafoya Fault. Therefore, it is speculated that the Changning earthquake penetrated the Dafoya Fault upward and triggered the associated fault activity of the Baixiangyan-Shizitan anticline, resulting in a series of subsequent earthquakes of magnitude 5 or above ( Fig.14 )

[0131] Using the P-wave arrival time data of 17,305 earthquakes recorded in the Changning earthquake area and its surrounding areas from January 2013 to July 2019 by the Sichuan Provincial Digital Seismic Network, the Yibin Local Seismic Network, and the newly added small-aperture mobile seismic array in the Changning area of ​​Yibin after 2016, the three-dimensional P-wave velocity structure data of the upper crust in the Changning earthquake area and its surrounding areas were inverted, and a three-dimensional P-wave velocity model of the upper crust in the Changning area was established ( Fig.15 ).

[0132] The spatial distribution of the P-wave velocity structure in the Changning area shows obvious lateral inhomogeneity ( Fig.16 ), and this lateral inhomogeneity gradually weakens with increasing depth. There are significant medium differences in the upper crust. The geological structure characteristics and stratum lithology of the region are important factors affecting the uneven distribution of shallow P-wave velocity structure.

[0133] (1) On the surface, the boundary between high- and low-velocity anomalies in the Changning-Shuanghe anticline is basically consistent with the anticline shape. The shallow velocity structure characteristics on both sides of the NW side, such as the Dafenba Fault, Dadiwan Fault, and Dafoya Fault, are different, which limits the trend of high-velocity anomalies to expand northward ( Fig.17 ).

[0134] (2) An obvious large-scale low-velocity anomaly distribution feature appears inside the Changning-Shuanghe anticline, including near the earthquake zone. The low-velocity anomaly zone at a depth of 8 km is consistent with the location of the detachment layer in the plastic basement of the Changning anticline ( Fig.18 ).

[0135] (3) The epicenter of the Changning M6.0 earthquake is located near the boundary zone where the velocity structure changes. The spatial distribution characteristics of the earthquake sequence are closely related to the velocity structure of the upper crust in the earthquake area. The sequence generally extends in a NW-SE direction along the boundary between high and low velocity anomalies ( Fig.18 ).

[0136] The shallow low-velocity anomaly morphology is consistent with the geological structure (mostly syncline) in which it is located. This low-velocity anomaly distribution feature is related to the wide and gentle syncline morphology and the relatively new lithology distribution in the syncline core. The low-velocity anomaly distribution below the Sinian System is related to the basement detachment layer. As a weak area that is plastic and prone to deformation, the detachment layer causes stress to accumulate easily in the brittle strata above it. It is precisely because of the existence of the low-velocity detachment layer that there are different deep and shallow structural backgrounds near the Shuanghechang fold in the Changning earthquake zone. The detachment layer in the basement varies greatly laterally and controls the development of shallow trough folds (Li Dahu, 2021).

[0137] Geological data and deep geophysical data show that the cap rock structure in the Sichuan Basin is relatively clear from the surface to the bottom of the Triassic System, and then it weakens rapidly downward and disappears above a low-intensity layer at a certain depth, indicating that the anticline structure is restricted by a certain deep slip surface in the sedimentary cap rock, and the folds are usually limited to a depth range of 3 to 6 km. Faults and anticline structures coexist. The place where the anticline rises is exactly where the fault dip angle becomes steeper and the fault throw increases; deep in the belly of the earth, as the two wings of the anticline become gentle, the fault dip angle also becomes smaller accordingly, the fault throw decreases sharply and finally disappears in the horizontal strata. This phenomenon shows that the anticline structure in the cap rock has a close genetic relationship with the fault activity. Chester (1991) believes that the formation and development of the anticline in this case is the result of the continuous extension of the fault, which is called "fault bending or fault extension anticline". The reverse faults closely related to the anticline can reach the surface directly or be hidden underground to form blind faults, which mainly depends on the development degree of the fault extension anticline.

[0138] Qian Hong et al. (1992) simplified the anticline structure of the Sichuan Basin: the cap rock in the Sichuan Basin is formed by the alternating deposition of brittle limestone, plastic mudstone and shale. The mechanical properties are obviously different, and the stratigraphic movement of each layer is uneven. Since the Cenozoic, the collision of plates and the rapid uplift of the Qinghai-Tibet Plateau have caused the Sichuan Basin to be subjected to strong intracontinental compression, and its horizontal tectonic force has affected the tectonic movement of the Sichuan Basin. The basement fault is generated and developed under the influence of strong northwest-southeast horizontal forces, and the cap rock above the basement is also compressed to varying degrees and at different times. The basement fault movement causes the basement morphology to change, resulting in more obstacles, and the movement of the cap rock is affected. At the basement fault, stress begins to accumulate here. When it accumulates to a certain extent, the brittle stratum breaks and forms a fracture surface with a small dip angle. The cap rock continues to slide and shorten, and develops into a reverse fault along the fracture surface with a small dip angle. As the cap rock continues to slide, the fracture surface gradually expands and the fault extends forward. Due to the alternating distribution of mudstone, shale and limestone, the dip angle increases when the fault moves into the plastic stratum. The cover slipped continuously and eventually developed into a reverse fault, and an anticline structure related to the fault propagation fold was formed on the fault slope. As the fault continued to develop and extend, a blind thrust fault developed in the fault axis.

[0139] According to previous earthquake studies, moderate to strong earthquakes in the Sichuan Basin generally occur in the core of the anticline or its steep wing, and the epicenter is located in the sedimentary cover above the crystalline basement, which is related to the blind thrust faults in the core of the anticline within the sedimentary cover. However, these moderate to strong earthquakes have no obvious relationship with the scale of the anticline, surface faults and their active age.

[0140] In summary, this special type of fold structure in the Sichuan Basin plays an important role in controlling the occurrence of earthquakes. Since the depth of the fault cutting is only 3 to 6 km, within this depth range, the Sichuan Basin is mainly distributed with mudstone, shale, and occasionally sandstone. Due to the low strength of the rock, a large amount of strain energy is not accumulated. This is the main reason for the low intensity of earthquakes in this type of structure. 3 / 4-6.0 magnitude moderate-strong earthquake activity has occurred frequently since 2008. Existing earthquake data show that this type of fold earthquake generally occurs on the upward-warping fault slope of the horizontal slip layer, with the epicenter located at the axis or steep wing of the anticline structure, and has the characteristics of low magnitude, shallow source, and relatively high epicenter intensity. It can be roughly determined that the Sichuan Basin is a region with a relatively stable seismic tectonic environment, and the intensity of historical earthquakes that have occurred already represents the actual seismic level in the region.

[0141] The embodiment of the present invention provides a seismic tectonic model construction system based on the seismic tectonic model construction method, the system specifically comprising:

[0142] Database construction module, used for database construction;

[0143] A model building module is used to build a three-dimensional digital elevation model, a three-dimensional geological structure model, a three-dimensional earthquake structure model, and a three-dimensional P-wave velocity structure model respectively;

[0144] The seismic environment analysis module is used for seismic environment analysis.

[0145] The system first collects and integrates the multi-source data required for the earthquake tectonic model through the database construction module, including geological exploration data, earthquake activity records, terrain data and related historical information. This module formats the multi-source data, removes outliers and sorts them to ensure the consistency and integrity of the data. The processed data is stored in a standardized database, providing high-quality data input required for subsequent model construction. At the same time, the database supports dynamic update functions, which can incorporate the latest earthquake monitoring and exploration data in real time.

[0146] The system generates an elevation model based on terrain data through the 3D digital elevation model construction submodule in the model construction module, accurately describing the surface undulation characteristics and regional boundaries. Subsequently, a 3D geological structure model is constructed by combining geological exploration data with fault information. This module uses advanced spatial interpolation algorithms and data fusion technology to generate a 3D distribution model of the crustal structure, fully displaying the characteristics of faults, rock layers and geological structures, and providing geological background support for earthquake structure analysis.

[0147] The 3D earthquake structure model combines earthquake activity data with the geological structure model to dynamically describe the activity characteristics and spatial correlation of earthquake structure faults. The system further constructs a 3D P-wave velocity structure model, analyzes the seismic wave propagation data through an inversion algorithm, and describes the velocity distribution and heterogeneity of the underground medium. The P-wave model can accurately reflect the propagation path of seismic waves and provide key parameter support for earthquake source location and earthquake prediction.

[0148] The seismic environment analysis module combines the three-dimensional seismic tectonic model with the P-wave velocity structure model to dynamically analyze the stress distribution and mechanical properties of the source area. By simulating the stress accumulation and release process in the source area, the module assesses the potential risk of fault activity and quantifies the geomechanical parameters of the source. The analysis results are used to predict the epicenter location, possible magnitude range and regional earthquake risk, providing a scientific basis for disaster prevention and mitigation decisions.

[0149] The system executes each step of the earthquake structure model construction method through the memory and processor of the computer device. The computer program instructions stored in the memory drive the processor to complete data processing, model generation and seismic environment analysis. The computer device quickly generates earthquake structure models and prediction results through real-time calculation and analysis, and supports dynamic visualization of model results, improving users' intuitive understanding of earthquake structures and risks.

[0150] The information data processing terminal is responsible for realizing the overall functions of the earthquake structure model construction system. The terminal completes the whole process from data collection to model generation and risk assessment by integrating the database construction module, model construction module and seismic environment analysis module. Users can obtain the model generation progress and analysis results in real time through the terminal, and adjust the emergency response strategy according to the prediction results. The high integration and real-time response capability of the terminal provide a reliable technical platform and operation tools for earthquake monitoring and disaster prevention and mitigation.

[0151] It should be noted that the embodiments of the present invention can be implemented by hardware, software, or a combination of software and hardware. The hardware part can be implemented using dedicated logic; the software part can be stored in a memory and executed by an appropriate instruction execution system, such as a microprocessor or dedicated design hardware. It can be understood by a person of ordinary skill in the art that the above-mentioned devices and methods can be implemented using computer executable instructions and / or contained in a processor control code, such as a carrier medium such as a disk, CD or DVD-ROM, a programmable memory such as a read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. Such code is provided on the carrier medium. The device and its modules of the present invention can be implemented by hardware circuits such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, etc., or programmable hardware devices such as field programmable gate arrays, programmable logic devices, etc., can also be implemented by software executed by various types of processors, and can also be implemented by a combination of the above-mentioned hardware circuits and software, such as firmware.

[0152] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A method for constructing an earthquake tectonic model, characterized in that: The method includes: S1: Database construction, collecting information from multiple data sources, including earthquake catalog data, geological maps, drilling data, seismic waveform data, seismic profiles and geological exploration data, integrating and preprocessing the data, and establishing a unified geological and seismic database; S2: Construction of three-dimensional digital elevation model, using remote sensing images, lidar and other technologies to obtain high-resolution terrain data, generate and calibrate digital elevation model; S3: Construction of 3D geological structure model: Based on the results of geological profile analysis, a 3D geological structure model is constructed using professional 3D geological modeling software, and the accuracy of the model is verified by comparing it with actual geological exploration data; S4: Construction of a three-dimensional seismic tectonic model. Based on the focal mechanism analysis and source distribution modeling, the source information of earthquake events is superimposed on the three-dimensional geological structure model to construct a three-dimensional seismic tectonic model, and the fault activity is analyzed in combination with historical earthquake data and fault geometry. S5: Construction of a three-dimensional P-wave velocity structure model. Collect seismic wave velocity measurement data and seismic tomography results, use seismic tomography technology to construct a three-dimensional P-wave velocity structure model, and calibrate the model with travel time data from actual earthquake records. S6: Analysis of the seismic environment: using the three-dimensional seismic tectonic model and the P-wave velocity structure model to analyze the distribution of the geostress field in the study area, assess the seismic hazard, identify potential sources of earthquake hazards, and develop earthquake prediction plans and disaster prevention and mitigation measures.

2. The method for constructing an earthquake tectonic model according to claim 1, characterized in that: In step S1, the collected data is subjected to denoising, data format conversion and missing data filling to ensure data quality and consistency; in step S2, high-resolution terrain data is acquired by using lidar, and the generated digital elevation model can accurately reflect the undulation of the terrain, and the model is corrected to eliminate errors in the data acquisition process; in step S5, the three-dimensional P-wave velocity structure model is corrected by the travel time data of the actual seismic record to improve the accuracy of the model and enable it to accurately reflect the P-wave velocity variation characteristics of different strata.

3. The method for constructing an earthquake tectonic model according to claim 1, characterized in that: The S1 specifically includes: Using geological profile data and comprehensive stratigraphic interpretation data as the main geological modeling data, and using borehole and seismic profile data as constraints, the quality control of the three-dimensional spatial position and geometric relationship of strata and faults is carried out; using earthquake relocation data to display the three-dimensional spatial distribution characteristics of earthquakes, and combining focal mechanism solution data to construct an initial seismogenic fault model; using crustal velocity structure data to establish a three-dimensional velocity structure model to support the rationality of the construction of the three-dimensional geological structure model and the comprehensive interpretation of the seismogenic structure characteristics; Since the data sources, types and formats of multi-source data fusion modeling are different, in order to integrate these data, the data format, scale, coordinate system and projection parameters must be unified first, so as to establish the original data database in the Gocad software.

4. The method for constructing an earthquake tectonic model according to claim 1, characterized in that: The S2 specifically includes: realizing digital simulation of ground terrain through limited terrain elevation data (i.e., digital expression of terrain surface morphology), which can more objectively display the geomorphic features of the study area; and combining DEM and GIS spatial analysis technology for geomorphic analysis, which can better obtain geomorphic information of the study area.

5. The method for constructing an earthquake tectonic model according to claim 1, characterized in that: The S3 specifically includes: (1) 3D stratigraphic model analysis; (2) Fault model analysis; (3) Geological body model analysis.

6. The method for constructing an earthquake tectonic model according to claim 1, characterized in that: The S4 specifically includes: (1) Analysis of characteristics of three-dimensional seismic sequences; (2) Analysis of three-dimensional earthquake fault models; (3) Comprehensive analysis of seismogenic structures.

7. The method for constructing an earthquake tectonic model according to claim 1, characterized in that: The S5 specifically includes: (1) Construction of a three-dimensional crustal velocity structure model; (2) Analysis of three-dimensional P-wave velocity structure model.

8. A seismic tectonic model construction system based on the seismic tectonic model construction method according to claims 1 to 6, characterized in that: The system specifically includes: Database construction module, used for database construction; A model building module is used to build a three-dimensional digital elevation model, a three-dimensional geological structure model, a three-dimensional earthquake structure model, and a three-dimensional P-wave velocity structure model respectively; The seismic environment analysis module is used for seismic environment analysis.

9. A computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the processor executes the steps of the method for constructing an earthquake tectonic model according to any one of claims 1 to 6.

10. An information data processing terminal, characterized in that: The information data processing terminal is used to implement the earthquake structure model construction system as described in claim 7.

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