A method and system for detecting earthquake swarms

Abstract

The present invention discloses a method and system for detecting earthquake swarms, the method comprising: obtaining an earthquake catalog of a region to be studied, calculating a minimum integrity magnitude; adjusting the data format of the earthquake catalog; performing screening calculations on earthquake clusters according to the minimum integrity magnitude and the adjusted earthquake catalog, obtaining earthquake cluster information in the region to be studied; setting detection constraints, performing earthquake swarm detection on the screened earthquake clusters based on the constraints, obtaining earthquake swarm sequence information in the region to be studied; also based on the obtained earthquake swarm sequence, weighting and summing the longitude and latitude of each earthquake therein, obtaining an equivalent position of the earthquake swarm; and calculating the sum of the energies of all earthquakes, obtaining an equivalent magnitude of the earthquake swarm; and then performing graphic drawing, completing the visual display of the earthquake swarm. The present invention is conducive to detecting earthquake swarms in earthquake clusters from aftershock sequences, foreshock sequences, etc., realizing rapid and automatic detection of earthquake swarms, greatly reducing repetitive manual labor, and significantly improving work efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of earthquake swarm detection, and more specifically to an earthquake swarm detection method and system, which are suitable for daily tracking and monitoring of earthquake swarm activity levels by earthquake practitioners. Background Art

[0002] As a manifestation of seismic activity, earthquake swarms usually refer to multiple earthquakes of similar magnitude occurring intensively in a small area in a short period of time. Their temporal and spatial distribution characteristics and dynamic changes can provide important information for studying the stress state and tectonic environment of underground media. Modern scientific research believes that changes in tectonic stress and the strength of earthquake-generating faults can easily promote earthquake swarm activity. Before many large earthquakes occur, abnormal earthquake swarm activities of varying degrees often occur near the epicenter, and strong earthquakes often occur against the background of increased earthquake swarm frequency. The sensitivity of earthquake swarms to changes in tectonic stress makes them suitable for the prediction of medium-to-strong earthquakes and an important seismological earthquake prediction indicator.

[0003] my country has built a number of digital seismic stations. On the basis of strengthening digital earthquake observation, a large-scale and standardized seismic observation network has been formed. This has laid a solid foundation for earthquake monitoring and prediction research. The monitoring capacity of earthquake swarm activities has also been gradually improved with the encryption of the observation network, and a large number of reliable earthquake cases have been accumulated to date. However, the identification and detection of earthquake swarms are relatively complicated. It is necessary to screen out earthquakes that are clustered in time and space from massive earthquake catalog data, and at the same time distinguish them from earthquake sequences such as main and aftermath types. At present, the monitoring of earthquake swarm activities mainly relies on the continuous tracking and accumulation of relevant practitioners. However, these accumulations are often concentrated in key areas, while other areas have less accumulation, which creates great difficulties for the retrospective study of earthquake swarms in a wide range and large areas.

[0004] Earthquake cluster refers to the phenomenon of a group of earthquakes occurring continuously in a short period of time, including aftershock sequences, foreshock sequences and earthquake swarms. In the prior art, Reasenberg (1985) proposed an earthquake cluster detection method based on a correlation window, which comprehensively considered the temporal and spatial distribution of earthquake sources in three-dimensional space, combined with statistical principles to search for earthquake clusters, and could obtain earthquakes clustered in time and space, with high computational efficiency. However, the detected earthquake clusters not only include earthquake swarms, but also other types of earthquake sequences, which makes it difficult to detect earthquake swarms.

[0005] In order to monitor the temporal and spatial distribution characteristics and changes of earthquake swarm activities, the methods usually used in actual work are as follows:

[0006] 1. Manual identification technology: technicians draw earthquake distribution and time frequency to search for earthquake swarms. It relies heavily on personal experience, takes a lot of time, and is inefficient.

[0007] 2. Search by dividing the space into rectangular grids: This method divides the search area into rectangular grids and searches for the location of the earthquake cluster by searching the number of earthquakes in the grids. However, the grid division method is relatively rigid and often over-estimates the number of earthquakes in the earthquake cluster. If the grid happens to be separated inside a certain earthquake cluster, it will affect the judgment of the earthquake cluster.

[0008] 3. Density-Based Spatial Clustering of Applications with Noise (DBSCAN): This method can obtain dense areas of earthquakes, so it can only obtain spatial clusters, but not temporal clusters. To obtain earthquake swarms, further manual identification is required.

[0009] Therefore, how to use earthquake catalog resources to quickly extract earthquake swarm sequence information, detect earthquake swarms in earthquake clusters from aftershock sequences, foreshock sequences, etc., to achieve the purpose of rapid and automatic detection of earthquake swarms, avoid subsequent manual processing to the greatest extent, and improve work efficiency, is a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0010] In view of this, the present invention provides a method and system for earthquake swarm detection that solves at least some of the above-mentioned technical problems, and can realize the rapid extraction of earthquake swarm sequence information by utilizing earthquake catalog resources, which is beneficial for detecting earthquake swarms in earthquake clusters from aftershock sequences, foreshock sequences, etc., so as to achieve the purpose of rapid and automatic detection of earthquake swarms, greatly reduce repetitive manual labor, and significantly improve work efficiency.

[0011] To achieve the above object, the technical solution adopted by the present invention is:

[0012] In a first aspect, an embodiment of the present invention provides a method for detecting earthquake swarms, the method comprising the following steps:

[0013] S1. Obtain the earthquake catalog of the area to be studied and calculate the minimum completeness magnitude;

[0014] S2. Adjust the earthquake catalog data format;

[0015] S3. Based on the minimum integrity magnitude, the earthquake clusters are screened and calculated according to the adjusted earthquake catalog to obtain earthquake cluster information in the area to be studied;

[0016] S4. Set detection constraints, perform earthquake swarm detection on the selected earthquake clusters based on the constraints, and obtain earthquake swarm sequence information in the area to be studied.

[0017] Preferably, the method further comprises:

[0018] S5. Based on the obtained earthquake swarm sequence, weight the longitude and latitude of each earthquake and add them up to obtain the equivalent position of the earthquake swarm; and calculate the sum of the energy of all earthquakes to obtain the equivalent magnitude of the earthquake swarm;

[0019] S6. Use the equivalent position and equivalent magnitude of the earthquake swarm obtained in combination with the earthquake occurrence time to draw a graph to complete the visual display of the earthquake swarm.

[0020] Preferably, in step S1, the minimum integrity magnitude is calculated by a maximum curvature method.

[0021] Preferably, in step S2, the earthquake catalog data format is adjusted to: year, month, day, latitude, longitude, and magnitude.

[0022] Preferably, in step S4, setting the detection constraint condition includes:

[0023] ① The difference between the largest magnitude and the second largest magnitude is less than or equal to 0.6, and the energy released by the largest earthquake accounts for less than or equal to 90% of the total energy released;

[0024] ②The total number of earthquakes is greater than the first preset value, and the maximum daily frequency is greater than the second preset value;

[0025] ③ There is quiet seismic activity during the preset time period before and after the earthquake sequence begins.

[0026] Preferably, the calculation formula of the equivalent position is:

[0027] lat eqv =lat 1 × 1 +lat 2 × 2 +…+lat n × n

[0028] lon eqv =lon 1 × 1 +lon 2 × 2 +…+lon n × n

[0029] In the formula, lat represents latitude; lat eqv represents the equivalent latitude; lon represents longitude; lon eqv Indicates equivalent longitude; w n represents the weighting coefficient of the nth earthquake; n represents the total number of earthquakes in the earthquake swarm sequence;

[0030] The calculation formula of the equivalent magnitude is:

[0031]

[0032] Where M eqv It represents the equivalent magnitude; E represents the energy released by the earthquake.

[0033] Preferably, in step S6, when drawing the graph, the size of the circle is used to represent the magnitude, and the circle is linearly enlarged as the magnitude increases; the center position of the circle is used to represent the earthquake position; and the color of the circle is used to represent the time when the largest earthquake in the entire earthquake sequence occurred.

[0034] In a second aspect, an embodiment of the present invention further provides an earthquake swarm detection system, which applies the above-mentioned earthquake swarm detection method to perform earthquake swarm detection and visual display, and the system includes:

[0035] The earthquake catalog acquisition module is used to obtain the earthquake catalog of the area to be studied and calculate the minimum integrity magnitude;

[0036] Earthquake catalog adjustment module, used to adjust the earthquake catalog data format;

[0037] An earthquake cluster acquisition module is used to screen and calculate earthquake clusters based on the minimum integrity magnitude and the adjusted earthquake catalog to obtain earthquake cluster information in the area to be studied;

[0038] The earthquake swarm detection module is used to set detection constraints, perform earthquake swarm detection on the selected earthquake clusters based on the constraints, and obtain earthquake swarm sequence information in the area to be studied.

[0039] Preferably, the system further comprises:

[0040] An equivalent calculation module is used to weight and sum the longitude and latitude of each earthquake in the obtained earthquake swarm sequence to obtain the equivalent position of the earthquake swarm; and calculate the sum of the energy of all earthquakes to obtain the equivalent magnitude of the earthquake swarm;

[0041] The graphics drawing module is used to draw graphics using the equivalent position and equivalent magnitude of the earthquake swarm obtained in combination with the earthquake occurrence time to complete the visual display of the earthquake swarm.

[0042] Compared with the prior art, the present invention has at least the following beneficial effects:

[0043] 1. The present invention provides an earthquake swarm detection method and system, which can realize the rapid extraction of earthquake swarm sequence information by using earthquake catalog resources, and facilitate the detection of earthquake swarms in earthquake clusters from aftershock sequences, foreshock sequences, etc. according to constraint conditions, so as to achieve the purpose of rapid and automatic detection of earthquake swarms, which is beneficial to greatly reduce repetitive manual labor and help to significantly improve work efficiency.

[0044] 2. The principle of the present invention is simple and intuitive, suitable for intelligent programming, and can realize the rapid extraction of earthquake swarm sequence information by using earthquake catalog resources. It expands the area of ​​earthquake swarm monitoring on the basis of greatly reducing the cost of earthquake swarm activity monitoring, greatly improves the richness of earthquake swarm activity record data, improves the quality of earthquake swarm activity monitoring programs, and improves the utilization rate of public resources.

[0045] 3. The present invention calculates the equivalent earthquake magnitude and position in the earthquake swarm sequence to characterize the distribution characteristics of the earthquake swarm, and the physical meaning is clear; the calculated position, magnitude and time of occurrence of the equivalent earthquake of the earthquake swarm are plotted on a plane map, which can intuitively and scientifically reflect the activity level and temporal and spatial distribution characteristics of the earthquake swarm, effectively optimize the drawing effect, and thus provide conditions for further analysis of earthquake activity and hazard.

[0046] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings.

[0047] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0049] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0050] Figure 1 A schematic flow chart of an earthquake swarm detection method provided in an embodiment of the present invention.

[0051] Figure 2 A schematic diagram of the original earthquake catalog format provided by an embodiment of the present invention.

[0052] Figure 3 A schematic diagram of calculating the minimum integrity magnitude provided by an embodiment of the present invention.

[0053] Figure 4 A schematic diagram of the adjusted earthquake catalog format provided in an embodiment of the present invention.

[0054] Figure 5A schematic diagram of a portion of earthquake clusters screened out according to an embodiment of the present invention.

[0055] Figure 6 A schematic diagram of earthquake swarm information in the Beijing area selected according to an embodiment of the present invention.

[0056] Figure 7 A schematic diagram of a magnitude-time image of an earthquake swarm in the Beijing area provided in an embodiment of the present invention.

[0057] Figure 8 A schematic plan view of earthquake swarms in Beijing and surrounding areas provided in an embodiment of the present invention.

[0058] Fig. 9 A schematic diagram of plotting earthquake swarms and their equivalent earthquakes on a plane provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0060] In the description of the present invention, it should be noted that: in some processes described in the specification and drawings of this application, multiple operations appearing in a specific order are included, but it should be clearly understood that these operations may not be performed in the order in which they appear in this document or may be performed in parallel. In addition, various serial numbers are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0061] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0062] See also Figure 1 As shown, the present invention provides a method for detecting earthquake swarms, which mainly includes the following steps:

[0063] 1. Obtain the earthquake catalog of the area to be studied and calculate the minimum integrity magnitude;

[0064] 2. Adjust the earthquake catalog data format;

[0065] 3. Based on the minimum complete magnitude, perform screening calculations on earthquake clusters according to the adjusted earthquake catalog to obtain earthquake cluster information in the area to be studied;

[0066] 4. Set detection constraints, perform earthquake swarm detection on the selected earthquake clusters based on the constraints, and obtain earthquake swarm information (earthquake swarm sequence) in the area to be studied.

[0067] In an optional embodiment, the method further comprises:

[0068] 5. Based on the obtained earthquake swarm sequence, the longitude and latitude of each earthquake are weighted and summed to obtain the equivalent position of the earthquake swarm; and the sum of the energy of all earthquakes is calculated to obtain the equivalent magnitude of the earthquake swarm;

[0069] 6. Use the equivalent position and equivalent magnitude of the earthquake swarm obtained in combination with the earthquake occurrence time to draw a graph and complete the visual display of the earthquake swarm.

[0070] The specific embodiments of the present invention are described in detail below:

[0071] Step 1: The earthquake catalog contains information such as the source location, time of occurrence and magnitude of the earthquake, and is summarized as catalog data in chronological order. First, it is necessary to obtain the earthquake catalog of the area to be studied. Limited by the density of the seismic network and the accuracy of observation, the integrity of earthquake catalogs in different regions and at different times varies. Earthquakes below the minimum integrity magnitude are not reliably monitored, so it is necessary to calculate the minimum integrity magnitude. The minimum integrity magnitude can be calculated using the maximum curvature method MAXC (Maximum Curvature), which can be easily achieved with only the earthquake catalog.

[0072] Step 2: Adjust the earthquake catalog data format to year, month, day, latitude, longitude, and magnitude to prepare for the next step of earthquake cluster screening.

[0073] Step 3: Input the earthquake catalog and use the earthquake cluster detection method based on the correlation window to detect earthquake clusters. The minimum magnitude of the detected earthquake is set to the minimum integrity magnitude. The output results contain information such as the location and time of occurrence of all earthquakes in the earthquake cluster sequence.

[0074] Step 4: Set detection constraints, perform earthquake swarm detection on the selected earthquake clusters based on the constraints, and obtain earthquake swarm sequence information in the area to be studied. The output results include the location and occurrence time of all earthquakes in the earthquake swarm sequence.

[0075] In the embodiment of the present invention, a preliminary earthquake cluster detection is first performed on the earthquake catalog. The difference between an earthquake cluster and other types of earthquake sequences is that there are two or more earthquakes with a small magnitude difference, the energy released by the largest earthquake accounts for no more than 90% of the total released energy, and the total number of earthquakes is large. Therefore, in order to distinguish earthquake clusters from aftershock sequences and foreshock sequences, the present invention performs further earthquake cluster detection based on the following three constraints:

[0076] ① The difference between the largest magnitude and the second largest magnitude is no more than 0.6, ensuring that there is no obvious main shock in the earthquake sequence, the energy is not concentrated in a single earthquake, and the energy released by the largest earthquake accounts for no more than 90% of the total released energy (see formula and explained below), thus distinguishing it from aftershock sequences and foreshock sequences, etc.;

[0077] When the magnitude difference between the largest earthquake and the second largest earthquake is 0.6, the energy ratio between the two is 10 1.5×0.6 =7.9433. Even if there are only these two earthquakes in the earthquake sequence, assuming that the energy of the next largest earthquake is 1, then the energy of the maximum earthquake is 7.9433. The energy released by the maximum earthquake accounts for the proportion of the total energy of 7.9433 / 8.9433=88.82%, which does not exceed 90%.

[0078] ② The total number of earthquakes shall be no less than 10, and the maximum daily frequency shall be no less than 3, to ensure a rich number of earthquakes and a high frequency in the earthquake sequence.

[0079] ③ The level of seismic activity is relatively calm before the start of the earthquake sequence and within half a month after the end, which is used to divide the start and end of the earthquake swarm sequence.

[0080] After the above processing, automated earthquake swarm detection can be achieved quickly and easily, avoiding subsequent manual processing to the greatest extent. It is suitable for daily tracking and monitoring of earthquake swarm activity levels by earthquake practitioners and has obvious advantages over existing solutions.

[0081] In order to intuitively display the spatial and temporal distribution of multiple earthquake swarms in the study area, they can be drawn on the plan view of the study area. However, since there may be multiple earthquake swarms distributed in the study area, if all earthquakes in the earthquake swarm are marked, it will affect the understanding of the spatial and temporal activity process of the earthquake swarm. Therefore, how to draw to better display the characteristics of the earthquake swarm is a difficult point. For common main-aftermath earthquakes, more than 90% of the total energy of the earthquake sequence is released by the largest earthquake. Therefore, when drawing, it is only necessary to mark the largest earthquake to depict the characteristics of the earthquake sequence. Currently, drawing an earthquake swarm also marks the largest earthquake in its sequence. However, for an earthquake swarm, most of its energy is often released through several earthquakes of similar magnitude. Therefore, only marking the position of the largest earthquake cannot fully reflect the distribution characteristics of the earthquake swarm. In the scheme of the present invention, the equivalent earthquake position and magnitude of each earthquake swarm are calculated through the following steps to optimize the drawing effect.

[0082] Step 5: Based on the earthquake swarm sequence obtained in the above way, weight and sum the longitude and latitude of each earthquake to obtain the equivalent position; calculate the sum of the energy of all earthquakes to obtain the equivalent magnitude. The relevant calculation principle and formula are as follows:

[0083] According to the Gutenberg-Richter empirical formula, the relationship between earthquake energy E and magnitude M can be expressed as:

[0084] IgE=4.8+1.5M

[0085] E=10 4.8+1.5M

[0086] Or:

[0087]

[0088] Therefore, for Earthquake 1 and Earthquake 2, the relationship between their energy and magnitude can be expressed as:

[0089] IgE 1 =4.8+1.5M 1

[0090] IgE 2 =4.8+1.5M 2

[0091] Subtracting the two, we get:

[0092]

[0093] Then we have:

[0094]

[0095] In a specific embodiment, in combination with the above principles, when marking the location of an earthquake swarm, each earthquake in the entire earthquake sequence can be weighted according to its energy proportion, so as to calculate its weighted position. For example, if there are n earthquakes in an earthquake swarm sequence, and the energy of the largest earthquake is set to 1, then the weight coefficient w of the i-th earthquake in the earthquake swarm sequence is i It can be expressed as:

[0096]

[0097] Multiply the latitude and longitude of each earthquake by the weighting factor w i And add them together to calculate the equivalent position of the earthquake swarm sequence, that is:

[0098] lat eqv =lat 1 × 1 +lat 2 × 2 +…+lat n × n

[0099] lon eqv =lon 1 × 1 +lon2 × 2 +…+lon n × n

[0100] In the formula, lat represents latitude; lat eqv represents the equivalent latitude; lon represents longitude; lon eqv Indicates equivalent longitude; w n represents the weighting coefficient of the nth earthquake; n represents the total number of earthquakes in the earthquake swarm sequence;

[0101] The equivalent magnitude can be obtained by calculating the energy released by all earthquakes in the entire earthquake swarm sequence, that is:

[0102]

[0103] Where M eqv Indicates equivalent magnitude.

[0104] Step 6: Plot the calculated equivalent earthquake position, magnitude and time of occurrence of the earthquake swarm on the plane map. Preferably, the size of the circle in the plane map represents the magnitude, which can be linearly enlarged as the magnitude increases; the center of the circle is the position of the equivalent earthquake; the color of the circle represents the time of occurrence of the largest earthquake in the entire earthquake sequence, and the visualization of the earthquake swarm is completed, which can intuitively and scientifically reflect the activity level and temporal and spatial distribution characteristics of the earthquake swarm.

[0105] The earthquake swarm detection effect and equivalent earthquake display effect of the present invention are experimentally verified as follows:

[0106] In one embodiment, in order to verify the earthquake swarm detection technical effect of the method of the present invention, the present invention selects earthquake catalog data from 2008 to 2022 in Beijing and surrounding areas for earthquake swarm detection:

[0107] First, collect the original earthquake catalog. The format of the original earthquake catalog is as follows: Figure 2 As shown; then the maximum curvature method MAXC is used to calculate the minimum integrity magnitude of the study area; as shown Figure 3 As shown in Figure 1, the calculated minimum integrity magnitude is 0.7. Further, the original earthquake catalog format is adjusted; the adjusted catalog format is as follows: Figure 4 As shown in Figure 1, the directory data format is: year, month, day, latitude, longitude, magnitude. Furthermore, the earthquake cluster detection method based on correlation window proposed by Reasenberg is used to perform preliminary earthquake cluster screening. Some of the selected earthquake clusters are shown in Figure 5 As shown in Figure 2; further, earthquake clusters in Beijing and surrounding areas are further detected, and earthquake clusters that meet the three-point constraint requirements are classified as earthquake clusters. The selected earthquake cluster information in Beijing is shown in Figure 2. Figure 6As shown in the figure, in the previous earthquake tracking work, it was concluded that there were only earthquake swarms in the Beijing area at the junction of Changping and Huairou from December 2010 to May 2011. The detection results of the present invention confirm the conclusion of this tracking work. Only two earthquake swarms were detected in the Beijing area, and the time and location were consistent. The earthquake sequence characteristics met the three-point constraint requirements. Figure 7 As shown, Figure 7 This is a magnitude-time image of the earthquake swarms in the Beijing area. It can be seen that the seismic activity was quiet before and after the two earthquake swarms. No major earthquake occurred before the start, so it was not an aftershock sequence; no major earthquake occurred afterwards, so it was not a foreshock sequence. The time interval between the two earthquake swarms was 19 days, which was more than 15 days, so they were separated into two earthquake swarms.

[0108] Finally, the earthquake swarm is plotted on a plane map. For a plane display of earthquake swarms in Beijing and surrounding areas, see Figure 8 As shown in the figure, the size of the circle represents the magnitude and the color represents the year in which the earthquake swarm occurred. Figure 8 The middle left part is the test results of the present invention (2008-2022), Figure 8 The middle right part is the earthquake swarm (2008-2021) accumulated by earthquake practitioners in their daily earthquake tracking work. It can be seen that the results of the present invention are highly consistent with the earthquake tracking results, proving the reliability of the method flow of the present invention. There are certain differences in details, but the results of the present invention are more accurate. Taking the earthquake swarm in May 2015 (40.65°N, 114.52°E) in the earthquake tracking results as an example, the results of the present invention did not detect this earthquake swarm. The largest earthquake in this earthquake sequence has a magnitude of 2.9, and the magnitude of the next largest earthquake is 2.0. The magnitude difference is large, and the largest earthquake is the first earthquake to occur, so it should be a main-aftermath sequence rather than an earthquake swarm sequence.

[0109] In one embodiment, in order to verify the equivalent earthquake display effect of the method of the present invention, the present invention selects the Jiashi earthquake group in 1997 to calculate the equivalent earthquake position and magnitude:

[0110] First, the longitude, latitude and magnitude of the earthquakes in the earthquake swarm sequence were obtained from the earthquake catalog of the Jiashi area in 1997. Then, according to the calculation formula of equivalent earthquake position and magnitude, the equivalent earthquake longitude was 77.0005, latitude was 39.6043, and magnitude was 6.9573. Finally, the earthquake swarm and its equivalent earthquakes were plotted on a plane map. The plane map can be found in Fig. 9 As shown, Fig. 9 In the figure, the left part is the earthquakes included in the earthquake swarm, and the right part is the earthquake swarm and its equivalent earthquakes. It can be seen that the location and magnitude (energy) of the equivalent earthquake better reflect the characteristics of the entire earthquake swarm sequence, which has obvious advantages over marking the largest earthquake.

[0111] It only takes a few hours for technicians in this field to automatically detect earthquake swarms in the massive earthquake catalogue nationwide since 2008 using the above method, and the detection time for small areas is even shorter, which greatly improves work efficiency and reduces the repetitive work of earthquake practitioners day after day.

[0112] From the description of the above embodiments, those skilled in the art can know that the present invention provides a method for detecting earthquake swarms, which has the following advantages:

[0113] 1. The present invention can realize the rapid extraction of earthquake swarm sequence information by utilizing earthquake catalog resources, and facilitates the detection of earthquake swarms in earthquake clusters from aftershock sequences, foreshock sequences, etc. according to constraint conditions, so as to achieve the purpose of rapid and automatic detection of earthquake swarms, which is beneficial to greatly reduce repetitive manual labor and contributes to significantly improving work efficiency.

[0114] 2. The principle of the present invention is simple and intuitive, suitable for intelligent programming, and can realize the rapid extraction of earthquake swarm sequence information by using earthquake catalog resources. It expands the area of ​​earthquake swarm monitoring on the basis of greatly reducing the cost of earthquake swarm activity monitoring, greatly improves the richness of earthquake swarm activity record data, improves the quality of earthquake swarm activity monitoring programs, and improves the utilization rate of public resources.

[0115] 3. The present invention calculates the equivalent earthquake magnitude and position in the earthquake swarm sequence to characterize the distribution characteristics of the earthquake swarm, and the physical meaning is clear; the calculated position, magnitude and time of occurrence of the equivalent earthquake of the earthquake swarm are plotted on a plane map, which can intuitively and scientifically reflect the activity level and temporal and spatial distribution characteristics of the earthquake swarm, effectively optimize the drawing effect, and thus provide conditions for further analysis of earthquake activity and hazard.

[0116] Furthermore, the present invention also provides an earthquake swarm detection system, which is applied to an earthquake swarm detection method in the above embodiment to perform earthquake swarm detection and visual display, and the system comprises:

[0117] The earthquake catalog acquisition module is used to obtain the earthquake catalog of the area to be studied and calculate the minimum integrity magnitude;

[0118] Earthquake catalog adjustment module, used to adjust the earthquake catalog data format;

[0119] An earthquake cluster acquisition module is used to screen and calculate earthquake clusters based on the minimum integrity magnitude and the adjusted earthquake catalog to obtain earthquake cluster information in the area to be studied;

[0120] The earthquake swarm detection module is used to set detection constraints, perform earthquake swarm detection on the selected earthquake clusters based on the constraints, and obtain earthquake swarm sequence information in the area to be studied.

[0121] In a specific embodiment, the system further comprises:

[0122] An equivalent calculation module is used to weight and sum the longitude and latitude of each earthquake in the obtained earthquake swarm sequence to obtain the equivalent position of the earthquake swarm; and calculate the sum of the energy of all earthquakes to obtain the equivalent magnitude of the earthquake swarm;

[0123] The graphics drawing module is used to draw graphics using the equivalent position and equivalent magnitude of the earthquake swarm obtained in combination with the earthquake occurrence time to complete the visual display of the earthquake swarm.

[0124] The implementation principle and technical effects of the system provided in the embodiment of the present invention are the same as those of the aforementioned method embodiment. For the sake of brief description, for matters not mentioned in the system embodiment, reference can be made to the corresponding contents in the aforementioned method embodiment, which will not be repeated here.

[0125] In addition, an embodiment of the present invention further provides a storage medium on which one or more programs readable by a computing device are stored. The one or more programs include instructions. When the instructions are executed by the computing device, the computing device executes an earthquake swarm detection method in the above embodiment.

[0126] In the embodiment of the present invention, the storage medium may be, for example, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination thereof. More specific examples of storage media (a non-exhaustive list) include: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disk read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanical encoding device, and any suitable combination thereof.

[0127] Those skilled in the art should understand that the embodiments of the present invention can be provided as methods, systems or computer program products, etc. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects.

[0128] It should be noted that the word "comprising" does not exclude the presence of components or steps not listed in the claims. The word "a" or "an" preceding a component does not exclude the presence of a plurality of such components. The invention can be implemented by means of hardware comprising several distinct components, and by means of a suitably programmed computer.

[0129] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0130] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for detecting earthquake swarms, characterized in that: The method comprises the following steps: S1. Obtain the earthquake catalog of the area to be studied and calculate the minimum completeness magnitude; S2. Adjust the data format of the earthquake catalog; adjust the data format of the earthquake catalog to: year, month, day, latitude, longitude, magnitude; S3. Based on the minimum integrity magnitude, the earthquake clusters are screened and calculated according to the adjusted earthquake catalog to obtain earthquake cluster information in the area to be studied; S4. Setting detection constraints, performing earthquake swarm detection on the selected earthquake clusters based on the constraints, and obtaining earthquake swarm sequence information in the area to be studied; setting detection constraints includes: ① The difference between the largest magnitude and the second largest magnitude is less than or equal to 0.6, and the energy released by the largest earthquake accounts for less than or equal to 90% of the total energy released; ②The total number of earthquakes is greater than the first preset value, and the maximum daily frequency is greater than the second preset value; ③ There is a quiet period of seismic activity before and after the earthquake sequence begins; S5. Based on the obtained earthquake swarm sequence, weight the longitude and latitude of each earthquake and add them up to obtain the equivalent position of the earthquake swarm; and calculate the sum of the energy of all earthquakes to obtain the equivalent magnitude of the earthquake swarm; The calculation formula of the equivalent position is: years eqv =lat1×w1+lat2×w2+…+lat n ×in n lon eqv =lon1×w1+lon2×w2+…+lon n ×w n In the formula, lat represents latitude; lat eqv represents the equivalent latitude; lon represents longitude; lon eqv Indicates equivalent longitude; w n It represents the weighting coefficient of the nth earthquake, that is, the energy proportion of the nth earthquake in the entire earthquake swarm sequence; n represents the total number of earthquakes in the earthquake swarm sequence; The calculation formula of the equivalent magnitude is: Where M eqv It represents the equivalent magnitude; E represents the energy released by the earthquake.

2. A method for detecting earthquake swarms according to claim 1, characterized in that: The method further includes: S6. Use the equivalent position and equivalent magnitude of the earthquake swarm obtained in combination with the earthquake occurrence time to draw a graph to complete the visual display of the earthquake swarm.

3. A method for detecting earthquake swarms according to claim 1, characterized in that: In the step S1, the minimum integrity magnitude is calculated by the maximum curvature method.

4. A method for detecting earthquake swarms according to claim 2, characterized in that: In step S6, when drawing the graph, the size of the circle is used to represent the magnitude, and the circle is linearly enlarged as the magnitude increases; the center position of the circle is used to represent the earthquake position; and the color of the circle is used to represent the time when the largest earthquake in the entire earthquake sequence occurred.

5. A earthquake swarm detection system, characterized in that: Using an earthquake swarm detection method as described in any one of claims 1 to 4, earthquake swarm detection and visualization are performed, and the system comprises: The earthquake catalog acquisition module is used to obtain the earthquake catalog of the area to be studied and calculate the minimum integrity magnitude; The earthquake catalog adjustment module is used to adjust the earthquake catalog data format; the earthquake catalog data format is adjusted to: year, month, day, latitude, longitude, and magnitude; An earthquake cluster acquisition module is used to screen and calculate earthquake clusters based on the minimum integrity magnitude and the adjusted earthquake catalog to obtain earthquake cluster information in the area to be studied; The earthquake swarm detection module is used to set detection constraints, perform earthquake swarm detection on the selected earthquake clusters based on the constraints, and obtain earthquake swarm sequence information in the area to be studied; setting detection constraints includes: ① The difference between the largest magnitude and the second largest magnitude is less than or equal to 0.6, and the energy released by the largest earthquake accounts for less than or equal to 90% of the total energy released; ②The total number of earthquakes is greater than the first preset value, and the maximum daily frequency is greater than the second preset value; ③ There is a quiet period of seismic activity before and after the earthquake sequence begins; An equivalent calculation module is used to weight and sum the longitude and latitude of each earthquake in the obtained earthquake swarm sequence to obtain the equivalent position of the earthquake swarm; and calculate the sum of the energy of all earthquakes to obtain the equivalent magnitude of the earthquake swarm; The calculation formula of the equivalent position is: years eqv =lat1×w1+lat2×w2+…+lat n ×in n lon eqv =lon1×w1+lon2×w2+…+lon n ×w n In the formula, lat represents latitude; lat eqv represents the equivalent latitude; lon represents longitude; lon eqv Indicates equivalent longitude; w n represents the weighting coefficient of the nth earthquake; n represents the total number of earthquakes in the earthquake swarm sequence; The calculation formula of the equivalent magnitude is: Where M eqv It represents the equivalent magnitude; E represents the energy released by the earthquake.

6. The earthquake swarm detection system according to claim 5, characterized in that: The system also includes: The graphics drawing module is used to draw graphics using the equivalent position and equivalent magnitude of the earthquake swarm obtained in combination with the earthquake occurrence time to complete the visual display of the earthquake swarm.

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