Double-bubble seismic source monitoring method based on water seismic exploration

Abstract

The invention relates to the field of seismic source monitoring, and discloses a double-bubble seismic source monitoring method based on water seismic exploration, which comprises the following steps: deploying a geophone array in a target sea area, recording seismic wave data generated by double bubbles by the geophone array, and taking frequency data of seismic waves as first target monitoring data; the seismic source identification module is used for identifying a seismic source, positioning the position of the seismic source by taking the propagation speed of the seismic wave as second target monitoring data and analyzing the time when the seismic wave reaches different detectors, respectively analyzing the amplitude attenuation characteristic change of the seismic wave in the propagation process and the propagation path of the seismic wave, and evaluating and analyzing the seismic scale; the earthquake risk level is evaluated, the earthquake occurrence probability is calculated based on the evaluated earthquake risk level, the accuracy of seismic source data acquisition is improved, the position of the seismic source can be accurately identified and positioned, and thus the accuracy of seismic probability prediction is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of earthquake source monitoring, and more specifically to a double-bubble earthquake source monitoring method based on underwater earthquake detection. Background Art

[0002] Earthquake detection relies on the propagation characteristics of seismic waves in underground media. Seismic waves include longitudinal waves (P waves) and transverse waves (S waves), which propagate at different speeds when encountering strata of different density and elasticity, resulting in reflection and refraction. Traditional seismic exploration methods usually use explosions or vibrators as seismic sources to detect underground structures through seismic waves. However, the application of these methods in underwater environments is limited. Therefore, the source monitoring method based on underwater seismic detection came into being. By setting two seismic sources on the exploration ship and accurately controlling the excitation sequence and time of the two seismic sources through a control device, efficient data acquisition can be achieved; However, the above process still has the following disadvantages: First, traditional seismic detection technology may have limitations in high-resolution imaging, especially in complex geological structures, making it difficult to clearly identify small-scale or shallow geological features, thus affecting the accuracy of source data acquisition; Second, traditional earthquake detection technology relies more on traditional seismic wave recording and analysis methods, which may be affected by a variety of factors, such as ships, marine environmental noise and weather conditions. These factors may cause interference and distortion of seismic wave signals, resulting in limited accuracy in earthquake source location, thus affecting the accurate calculation of the earthquake source location; Third, traditional earthquake detection technology may have difficulty analyzing the attenuation changes and path propagation of seismic waves, and lacks sophisticated earthquake risk assessment, which affects the accuracy of earthquake assessment. Summary of the invention

[0003] In order to overcome the above-mentioned defects of the prior art, the present invention provides a double-bubble seismic source monitoring method based on underwater seismic detection to solve the problems existing in the above-mentioned background technology.

[0004] The present invention provides the following technical solution: a double-bubble seismic source monitoring method based on underwater seismic detection, comprising: S1: By deploying a seismic sensor array in the target sea area and installing a double bubble source system on the water surface; S2: The release of the double bubbles is controlled by a controller, and the seismic wave data generated by the double bubbles is recorded by a seismic detector array; S3: using the frequency data of the seismic wave as the first target monitoring data, analyzing the change characteristics of the first target monitoring data to identify the earthquake source; S4: by taking the propagation speed of the seismic wave as the second target monitoring data, analyzing the second target monitoring data and the time when the seismic wave reaches different geophones, the source position is calculated for locating the source position; S5: Based on the earthquake source location, monitor the state of earthquake source activity, obtain the attenuation coefficient by analyzing the change of amplitude attenuation characteristics of earthquake waves during propagation, and obtain the path propagation coefficient by analyzing the propagation path of earthquake waves; S6: Evaluate and analyze the earthquake scale based on the amplitude attenuation characteristic changes and propagation paths of seismic waves to obtain the earthquake scale assessment coefficient; S7: Assess the earthquake risk level based on the earthquake scale assessment coefficient, and recommend a calculation model for the probability of earthquake occurrence based on the assessed earthquake risk level.

[0005] Preferably, the S1 first selects a suitable target sea area, deploys detectors based on the seabed topography, water depth and seabed structure of the target sea area, uses GPS to determine the position of each deployed detector, fixes the detector on the seabed, and then connects it to the data recorder through a cable. At the same time, a double bubble source system is installed at a location on the water surface away from ships and other obstacles, and then connected to the power supply of the charge and discharge control circuit.

[0006] Preferably, S2 uses double bubbles as seismic sources, and the seismic detector array receives and records the pressure wave signals generated when the bubbles are quickly released in the water as seismic wave signals, and then records the seismic wave data in real time through a data recorder. The collected seismic wave data include the amplitude, frequency and arrival time of the seismic waves.

[0007] Preferably, the specific steps of S2 for the controller to control the release of double bubbles are: Step S211: Open the valve of the gas tank, pre-fill a certain amount of gas into the airbag of the double bubble seismic source, and use GPS to locate the correct position of the seismic source release; Step S212: the controller instructs the source system to dive to a predetermined depth, and the controller opens the valve of the first bubble according to preset parameters, releases the first bubble, and records the time and initial state of the bubble release; Step S213: After a preset time interval, the controller opens the valve of the second bubble, releases the second bubble, and records the release time and state of the second bubble.

[0008] Preferably, S3 performs spectrum analysis on the seismic wave signal, uses fast Fourier transform to convert the time domain signal into a frequency domain signal, calculates the amplitude spectrum and the phase spectrum, determines the characteristic frequency range of the double bubble source, and extracts the amplitude and phase within the characteristic frequency range as the first target monitoring data, and calculates the change characteristics of the first target monitoring data by performing feature analysis on the change of the first target monitoring data: , Indicates time point Monitor the amplitude spectrum of the frequency domain signal, Indicates time point Monitor the amplitude spectrum of the frequency domain signal, Indicates time point Monitor the phase spectrum of the frequency domain signal, Indicates time point Monitor the phase spectrum of frequency domain signals; By comparing the change feature H of the first target monitoring data with the preset feature threshold For comparison, if , it means that the earthquake source activity is identified and the earthquake source location is analyzed. , it means that no earthquake source activity has been identified and the target sea area will continue to be monitored.

[0009] Preferably, the specific analysis method of S4 for locating the earthquake source position is: Step S411: generating seismic waves by releasing two bubbles in water, and using a plurality of geophones distributed at different locations to record the arrival time of the seismic waves; Step S412: preprocessing the signal recorded by the geophone, including denoising and filtering, so as to extract the seismic wave signal; Step S413: Based on the signal between each pair of detectors, the P wave velocity and the S wave velocity are calculated respectively, that is, , ,in, represents the P-wave velocity, i.e., body wave, represents the S-wave velocity, i.e., surface wave, and d represents the distance between the two detectors. It represents the time difference of P wave arriving at two detectors. It indicates the time difference between the S wave reaching the two geophones. It is used to monitor the propagation speed of seismic waves in the medium in real time by taking the P wave velocity and S wave velocity as the second target monitoring data. Step S414: Set the location coordinates of the earthquake source to , by using three or more geophone locations, P-wave velocity, and S-wave velocity to establish a set of equations to calculate the source location for ,in, represents the coordinates of the earthquake source location, represents the position coordinates of the i-th detector, represents the time when the P wave reaches the i-th detector, represents the time when the S wave reaches the i-th detector, Indicates the time when the seismic wave originates, usually set to the time when the first detector receives the P wave.

[0010] Preferably, the S5 records the amplitude of the seismic wave at each detector, identifies and extracts the first arrival wave of the seismic wave, and then analyzes the change of the amplitude of the first arrival wave with distance, thereby calculating the attenuation coefficient: ,in, represents the amplitude of the first arrival wave at a distance r from the earthquake source, represents the amplitude of the first arrival wave at the source, and r represents the distance from the source to the detector; The specific analysis method of the path propagation coefficient is: Step S511: Record the time when the seismic wave reaches each detector and calculate the straight-line distance between the geophone and the source ; Step S512: Analyze the propagation path of the seismic wave from the source to the underground medium of the geophone by using ray tracing technology; Step S513: Select a clear P wave or S wave first arrival as the analysis object, so as to analyze the wave velocity reaching each detector. The specific calculation formula is: ,in, represents the velocity of the seismic wave reaching the i-th detector; Step S513: Statistical analysis is performed on the wave velocities of all detectors to calculate the path propagation coefficient: ,in, It represents the average velocity of seismic waves reaching all geophones, and N represents the total number of geophones.

[0011] Preferably, S6 performs a comprehensive analysis by combining the attenuation coefficient and the path propagation coefficient, and calculates the earthquake scale assessment coefficient as , M represents the magnitude of the earthquake, R represents the path propagation coefficient, represents the attenuation coefficient, D represents the distance from the source to the detector, and e represents a constant.

[0012] Preferably, the S7 can classify earthquakes into different risk levels based on the earthquake scale assessment coefficient, and the risk levels divided are low level, medium level and high level; based on the determined risk level, different statistical models are assigned to the earthquake occurrence probability calculation method; by respectively setting the first threshold and the second threshold Compare with the earthquake scale assessment coefficient C to determine the earthquake risk level. , the magnitude of the earthquake is classified as low, and the Poisson distribution model is used to calculate the probability of earthquake occurrence. , the magnitude of the earthquake is classified as medium, and the probability of earthquake occurrence is calculated using a time-dependent model. , the magnitude of the earthquake is divided into high levels, and the probability of earthquake occurrence is calculated using a clustering model or a conditional probability model.

[0013] Preferably, S7 is based on displaying the earthquake risk level assessment results and earthquake probability results in a visual manner through an application program, thereby pushing the earthquake risk information to the user terminal in real time.

[0014] Technical effects and advantages of the present invention: The present invention deploys a seismic detector array in the target sea area, and installs a double-bubble seismic source system on the water surface, controls the release of double bubbles based on a controller, and records seismic wave data generated by the double bubbles by the seismic detector array, uses the frequency data of the seismic wave as the first target monitoring data, analyzes the change characteristics of the first target monitoring data, and uses it to identify the seismic source, uses the propagation speed of the seismic wave as the second target monitoring data, and analyzes the time when the seismic wave reaches different geophones to locate the seismic source position, monitors the seismic source activity state through the seismic source position, analyzes the amplitude attenuation characteristic changes of the seismic wave in the propagation process and the propagation path of the seismic wave respectively, thereby monitoring the characteristic changes during the propagation of the seismic wave, evaluates and analyzes the earthquake scale based on the amplitude attenuation characteristic changes of the seismic wave and the propagation path, thereby evaluating the earthquake risk level, and calculates the probability of earthquake occurrence based on the evaluated earthquake risk level, which is helpful to improve the resolution of seismic data, better detect small-scale structures and details, thereby improving the accuracy of seismic source data acquisition, can solve the problem that the traditional seismic detection technology is affected by environmental factors and causes inaccurate calculation of the seismic source position, is conducive to fine analysis and evaluation of earthquake risks, thereby improving the accuracy of earthquake evaluation. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a diagram of the method steps of the present invention.

[0016] Figure 2 It is a system structure block diagram of the present invention. DETAILED DESCRIPTION

[0017] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the present invention. In addition, the forms of the various structures recorded in the following embodiments are merely illustrative. The double-bubble source monitoring method based on underwater seismic detection involved in the present invention is not limited to the various structures recorded in the following embodiments. All other implementations obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0018] like Figure 1 The present embodiment provides a double-bubble seismic source monitoring method based on underwater seismic detection, comprising: S1: By deploying a seismic detector array in the target sea area and installing a double bubble source system on the water surface.

[0019] In this embodiment, the S1 first selects a suitable target sea area, deploys detectors based on the seabed topography, water depth and seabed structure of the target sea area, uses GPS to determine the position of each deployed detector, fixes the detector on the seabed, and then connects it to the data recorder through a cable. At the same time, at least one location on the water surface away from ships and other obstacles is selected to install a double bubble source system, and then it is connected to the charge and discharge control circuit with a power supply.

[0020] It should be specifically noted that by deploying at least one seismic detector array on the water surface, seismic waves from different directions of the earthquake source can be received simultaneously. The double bubble earthquake source can accurately control the time and position of bubble release, so that the position and activity of the earthquake source can be accurately monitored.

[0021] S2: The release of the double bubbles is controlled by a controller, and the seismic wave data generated by the double bubbles is recorded by a seismic detector array.

[0022] In this embodiment, S2 uses double bubbles as seismic sources, and the seismic detector array receives and records the pressure wave signals generated when the bubbles are quickly released in the water as seismic wave signals, and then records the seismic wave data in real time through a data recorder. The collected seismic wave data includes the amplitude, frequency and arrival time of the seismic waves.

[0023] The specific steps for the controller to control the release of double bubbles are: Step S211: Open the valve of the gas tank, pre-fill a certain amount of gas into the airbag of the double bubble seismic source, and use GPS to locate the correct position of the seismic source release; Step S212: the controller instructs the source system to dive to a predetermined depth, and the controller opens the valve of the first bubble according to preset parameters, releases the first bubble, and records the time and initial state of the bubble release; Step S213: After a preset time interval, the controller opens the valve of the second bubble, releases the second bubble, and records the release time and state of the second bubble.

[0024] It should be specifically explained that the double bubble source is excited by the control circuit to generate seismic waves, which interact with the underground medium during the propagation process to produce reflection, refraction and other phenomena. These seismic wave signals are received and recorded by the receiver, and then the data recorder begins to continuously record the time, amplitude and frequency of the seismic waves arriving at each detector.

[0025] S3: Using the frequency data of seismic waves as first target monitoring data, analyzing the change characteristics of the first target monitoring data to identify the earthquake source.

[0026] In this embodiment, S3 performs spectrum analysis on the seismic wave signal, uses fast Fourier transform to convert the time domain signal into a frequency domain signal, calculates the amplitude spectrum and phase spectrum, determines the characteristic frequency range of the double bubble source, and extracts the amplitude and phase within the characteristic frequency range as the first target monitoring data. By performing feature analysis on the change of the first target monitoring data, the change feature of the first target monitoring data is calculated as follows: , Indicates time point Monitor the amplitude spectrum of the frequency domain signal, Indicates time point Monitor the amplitude spectrum of the frequency domain signal, Indicates time point Monitor the phase spectrum of the frequency domain signal, Indicates time point Monitor the phase spectrum of a frequency domain signal.

[0027] By comparing the change feature H of the first target monitoring data with the preset feature threshold For comparison, if , it means that the earthquake source activity is identified and the earthquake source location is analyzed. , it means that no earthquake source activity has been identified and the target sea area will continue to be monitored.

[0028] It should be specifically explained that, first, the seismic wave signal is analyzed in the frequency domain, and the specific calculation formula for extracting the frequency data is as follows using the fast Fourier transform:

[0029] in, represents the frequency domain signal, represents the time domain signal, j represents the imaginary unit, f represents the frequency, and e represents the constant.

[0030] Then calculate the amplitude spectrum of the frequency domain signal separately and phase spectrum for

[0031]

[0032] in, and Respectively The real and imaginary parts of .

[0033] The feature extraction formula for extracting the amplitude and phase within the characteristic frequency range as the first target monitoring data is:

[0034] in, represents the set of characteristic frequencies, represents the amplitude threshold, and Indicates the range of characteristic frequencies.

[0035] Different types of seismic waves, such as P waves and S waves, have different frequency characteristics, which can help identify the type of earthquake source.

[0036] S4: By taking the propagation speed of the seismic wave as the second target monitoring data, analyzing the second target monitoring data and the time when the seismic wave arrives at different detectors, the source position is calculated for locating the source position.

[0037] In this embodiment, the specific analysis process of S4 for locating the earthquake source position includes: Step S411: generating seismic waves by releasing two bubbles in water, and using a plurality of geophones distributed at different locations to record the arrival time of the seismic waves; Step S412: preprocessing the signal recorded by the geophone, including denoising and filtering, so as to extract the seismic wave signal; Step S413: Based on the signal between each pair of detectors, the P wave velocity and the S wave velocity are calculated respectively, that is, , ,in, represents the P-wave velocity, i.e., body wave, represents the S-wave velocity, i.e., surface wave, and d represents the distance between the two detectors. It represents the time difference of P wave arriving at two detectors. It indicates the time difference between the S wave reaching the two geophones. It is used to monitor the propagation speed of seismic waves in the medium in real time by taking the P wave velocity and S wave velocity as the second target monitoring data. Step S414: Set the location coordinates of the earthquake source to , by using three or more geophone locations, P-wave velocity, and S-wave velocity to establish a set of equations to calculate the source location for ,in, represents the coordinates of the earthquake source location, represents the position coordinates of the i-th detector, represents the time when the P wave reaches the i-th detector, represents the time when the S wave reaches the i-th detector, Indicates the time when the seismic wave originates, usually set to the time when the first detector receives the P wave.

[0038] S5: Based on the source location, monitor the state of source activity, obtain the attenuation coefficient by analyzing the changes in the amplitude attenuation characteristics of the seismic wave during propagation, and obtain the path propagation coefficient by analyzing the propagation path of the seismic wave.

[0039] In this embodiment, S5 records the amplitude of the seismic wave at each detector, identifies and extracts the first arrival wave of the seismic wave, and then analyzes the change of the amplitude of the first arrival wave with distance, thereby calculating the attenuation coefficient: ,in, represents the amplitude of the first arrival wave at a distance r from the earthquake source, represents the amplitude of the first arrival wave at the source, and r represents the distance from the source to the detector.

[0040] The specific analysis process of the path propagation coefficient includes: Step S511: Record the time when the seismic wave reaches each detector and calculate the straight-line distance between the geophone and the source ; Step S512: Analyze the propagation path of the seismic wave from the source to the underground medium of the geophone by using ray tracing technology; Step S513: Select a clear P wave or S wave first arrival as the analysis object, so as to analyze the wave velocity reaching each detector. The specific calculation formula is: ,in, represents the velocity of the seismic wave reaching the i-th detector; Step S513: Statistical analysis is performed on the wave velocities of all detectors to calculate the path propagation coefficient: ,in, It represents the average velocity of seismic waves reaching all geophones, and N represents the total number of geophones.

[0041] S6: Evaluate and analyze the earthquake scale based on the changes in the amplitude attenuation characteristics of the seismic waves and the propagation path to obtain the earthquake scale assessment coefficient.

[0042] In this embodiment, S6 performs a comprehensive analysis by combining the attenuation coefficient and the path propagation coefficient, and calculates the earthquake scale assessment coefficient as , M represents the magnitude of the earthquake, R represents the path propagation coefficient, represents the attenuation coefficient, D represents the distance from the source to the detector, and e represents a constant.

[0043] S7: Assess the earthquake risk level based on the earthquake scale assessment coefficient, and recommend a calculation model for the probability of earthquake occurrence based on the assessed earthquake risk level.

[0044] In this embodiment, S7 can classify earthquakes into different risk levels based on the earthquake scale assessment coefficient, and the risk levels divided are low level, medium level and high level; based on the determined risk level, different statistical models are assigned to the earthquake occurrence probability calculation method; by respectively setting the first threshold and the second threshold Compare with the earthquake scale assessment coefficient C to determine the earthquake risk level. , the magnitude of the earthquake is classified as low, and the Poisson distribution model is used to calculate the probability of earthquake occurrence. , the magnitude of the earthquake is classified as medium, and the probability of earthquake occurrence is calculated using a time-dependent model. , the magnitude of the earthquake is divided into high levels, and the probability of earthquake occurrence is calculated using a clustering model or a conditional probability model.

[0045] The earthquake risk level assessment results and earthquake probability results are displayed in a visual manner through an application, thereby pushing earthquake risk information to user terminals in real time.

[0046] like Figure 2 The embodiment shown provides an implementation system corresponding to a double-bubble seismic source monitoring method based on underwater seismic detection, including a detector deployment module, a data acquisition module, a seismic source identification module, a seismic source position detection module, a seismic source activity analysis module, a seismic source scale assessment module and a seismic source grade classification module, the detector deployment module is connected to the data acquisition module, the data acquisition module is connected to the seismic source identification module, the seismic source identification module is connected to the seismic source position detection module, the seismic source position detection module is connected to the seismic source activity analysis module, the seismic source activity analysis module is connected to the seismic source scale assessment module, the seismic source scale assessment module is connected to the seismic source grade classification module, and the database is connected to all modules.

[0047] The geophone deployment module deploys a geophone array in the target sea area and installs a double bubble source system on the water surface; The data acquisition module controls the release of the double bubbles through a controller, and the seismic wave data generated by the double bubbles are recorded by a seismic detector array; The earthquake source identification module uses the frequency data of the earthquake wave as the first target monitoring data and analyzes the change characteristics of the first target monitoring data to identify the earthquake source; The earthquake source location detection module uses the propagation speed of the seismic wave as the second target monitoring data, analyzes the second target monitoring data and the time when the seismic wave reaches different detectors, and calculates the earthquake source location for locating the earthquake source location; The earthquake source activity analysis module monitors the earthquake source activity state based on the earthquake source position, obtains the attenuation coefficient by analyzing the change of the amplitude attenuation characteristics of the earthquake wave during the propagation process, and obtains the path propagation coefficient by analyzing the propagation path of the earthquake wave; The earthquake source scale assessment module assesses and analyzes the earthquake scale based on the amplitude attenuation characteristic changes and propagation paths of the earthquake waves to obtain an earthquake scale assessment coefficient; The earthquake source classification module evaluates the earthquake risk level based on the earthquake scale assessment coefficient, and recommends a calculation model for the probability of earthquake occurrence based on the assessed earthquake risk level; The database is used to store data output by all modules.

[0048] The present invention deploys a seismic detector array in the target sea area, and installs a double-bubble seismic source system on the water surface, controls the release of double bubbles based on a controller, and records seismic wave data generated by the double bubbles by the seismic detector array, uses the frequency data of the seismic wave as the first target monitoring data, analyzes the change characteristics of the first target monitoring data, and uses it to identify the seismic source, uses the propagation speed of the seismic wave as the second target monitoring data, and analyzes the time when the seismic wave reaches different geophones to locate the seismic source position, monitors the seismic source activity state through the seismic source position, analyzes the amplitude attenuation characteristic changes of the seismic wave in the propagation process and the propagation path of the seismic wave respectively, thereby monitoring the characteristic changes during the propagation of the seismic wave, evaluates and analyzes the earthquake scale based on the amplitude attenuation characteristic changes of the seismic wave and the propagation path, thereby evaluating the earthquake risk level, and calculates the probability of earthquake occurrence based on the evaluated earthquake risk level, which is helpful to improve the resolution of seismic data, better detect small-scale structures and details, thereby improving the accuracy of seismic source data acquisition, can solve the problem that the traditional seismic detection technology is affected by environmental factors and causes inaccurate calculation of the seismic source position, is conducive to fine analysis and evaluation of earthquake risks, thereby improving the accuracy of earthquake evaluation.

[0049] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0050] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A double-bubble seismic source monitoring method based on underwater seismic detection, characterized in that: include: S1: By deploying a seismic sensor array in the target sea area and installing a double bubble source system on the water surface; S2: The release of the double bubbles is controlled by a controller, and the seismic wave data generated by the double bubbles is recorded by a seismic detector array; S3: using the frequency data of the seismic wave as the first target monitoring data, analyzing the change characteristics of the first target monitoring data to identify the earthquake source; S4: by taking the propagation speed of the seismic wave as the second target monitoring data, analyzing the second target monitoring data and the time when the seismic wave reaches different geophones, the source position is calculated for locating the source position; S5: Based on the earthquake source location, monitor the state of earthquake source activity, obtain the attenuation coefficient by analyzing the change of amplitude attenuation characteristics of earthquake waves during propagation, and obtain the path propagation coefficient by analyzing the propagation path of earthquake waves; S6: Evaluate and analyze the earthquake scale based on the amplitude attenuation characteristic changes and propagation paths of seismic waves to obtain the earthquake scale assessment coefficient; S7: Assess the earthquake risk level based on the earthquake scale assessment coefficient, and recommend a calculation model for the probability of earthquake occurrence based on the assessed earthquake risk level.

2. The double-bubble seismic source monitoring method based on underwater seismic detection according to claim 1 is characterized in that: The S1 first selects a suitable target sea area, deploys detectors based on the seabed topography, water depth and seabed structure of the target sea area, uses GPS to determine the position of each deployed detector, fixes the detector on the seabed, and then connects it to the data recorder through a cable. At the same time, a double bubble source system is installed at a location on the water surface away from ships and other obstacles, and then connected to the power supply of the charge and discharge control circuit.

3. The double-bubble seismic source monitoring method based on underwater seismic detection according to claim 1 is characterized in that: The S2 uses double bubbles as seismic sources, and the seismic detector array receives and records the pressure wave signals generated when the bubbles are quickly released in the water as seismic wave signals, and then records the seismic wave data in real time through a data recorder. The collected seismic wave data includes the amplitude, frequency and arrival time of the seismic waves.

4. The double-bubble seismic source monitoring method based on underwater seismic detection according to claim 1 is characterized in that: The specific steps of S2 for the controller to control the release of double bubbles are: Step S211: Open the valve of the gas tank, pre-fill a certain amount of gas into the airbag of the double bubble seismic source, and use GPS to locate the correct position of the seismic source release; Step S212: the controller instructs the source system to dive to a predetermined depth, and the controller opens the valve of the first bubble according to preset parameters, releases the first bubble, and records the time and initial state of the bubble release; Step S213: After a preset time interval, the controller opens the valve of the second bubble, releases the second bubble, and records the release time and state of the second bubble.

5. The double-bubble seismic source monitoring method based on underwater seismic detection according to claim 1 is characterized in that: S3 performs spectrum analysis on the seismic wave signal, uses fast Fourier transform to convert the time domain signal into a frequency domain signal, calculates the amplitude spectrum and the phase spectrum, determines the characteristic frequency range of the double bubble source, and extracts the amplitude and phase within the characteristic frequency range as the first target monitoring data, and calculates the change characteristics of the first target monitoring data by performing feature analysis on the change of the first target monitoring data: , Indicates time point Monitor the amplitude spectrum of the frequency domain signal, Indicates time point Monitor the amplitude spectrum of the frequency domain signal, Indicates time point Monitor the phase spectrum of the frequency domain signal, Indicates time point Monitor the phase spectrum of frequency domain signals; By comparing the change feature H of the first target monitoring data with the preset feature threshold For comparison, if , it means that the earthquake source activity is identified and the earthquake source location is analyzed. , it means that no earthquake source activity has been identified and the target sea area will continue to be monitored.

6. The double-bubble source monitoring method based on underwater seismic detection according to claim 1 is characterized in that: The specific analysis method of S4 for locating the earthquake source position is: Step S411: generating seismic waves by releasing two bubbles in water, and using a plurality of geophones distributed at different locations to record the arrival time of the seismic waves; Step S412: preprocessing the signal recorded by the geophone, including denoising and filtering, so as to extract the seismic wave signal; Step S413: Based on the signal between each pair of detectors, the P wave velocity and the S wave velocity are calculated respectively, that is, , ,in, represents the P-wave velocity, i.e., body wave, represents the S-wave velocity, i.e., surface wave, and d represents the distance between the two detectors. It represents the time difference of P wave arriving at two detectors. It indicates the time difference between the S wave reaching the two geophones. It is used to monitor the propagation speed of seismic waves in the medium in real time by taking the P wave velocity and S wave velocity as the second target monitoring data. Step S414: Set the location coordinates of the earthquake source to , by using three or more geophone locations, P-wave velocity, and S-wave velocity to establish a set of equations to calculate the source location for ,in, represents the coordinates of the earthquake source location, represents the position coordinates of the i-th detector, represents the time when the P wave reaches the i-th detector, represents the time when the S wave reaches the i-th detector, Represents the origin time of the seismic wave, which is set to the time when the first detector receives the P wave.

7. The double-bubble seismic source monitoring method based on underwater seismic detection according to claim 1 is characterized in that: The S5 records the amplitude of the seismic wave at each detector, identifies and extracts the first arrival wave of the seismic wave, and then analyzes the change of the amplitude of the first arrival wave with distance, thereby calculating the attenuation coefficient: ,in, represents the amplitude of the first arrival wave at a distance r from the earthquake source, represents the amplitude of the first arrival wave at the source, and r represents the distance from the source to the detector; The specific analysis method of the path propagation coefficient is: Step S511: Record the time when the seismic wave reaches each detector and calculate the straight-line distance between the geophone and the source ; Step S512: Analyze the propagation path of the seismic wave from the source to the underground medium of the geophone by using ray tracing technology; Step S513: Select a clear P wave or S wave first arrival as the analysis object, so as to analyze the wave velocity reaching each detector. The specific calculation formula is: ,in, represents the velocity of the seismic wave reaching the i-th detector; Step S513: Perform statistical analysis on the wave velocities of all detectors and calculate the path propagation coefficient: ,in, It represents the average velocity of seismic waves reaching all geophones, and N represents the total number of geophones.

8. The double-bubble source monitoring method based on underwater seismic detection according to claim 1 is characterized in that: The S6 performs a comprehensive analysis by combining the attenuation coefficient and the path propagation coefficient, and calculates the earthquake scale assessment coefficient as , M represents the magnitude of the earthquake, R represents the path propagation coefficient, represents the attenuation coefficient, D represents the distance from the source to the detector, and e represents a constant.

9. The double-bubble source monitoring method based on underwater seismic detection according to claim 1 is characterized in that: The S7 can classify earthquakes into different risk levels based on the earthquake scale assessment coefficient, and the risk levels are low, medium and high; based on the determined risk levels, different statistical models are assigned to the earthquake occurrence probability calculation method; by respectively setting the first threshold and the second threshold Compare with the earthquake scale assessment coefficient C to determine the earthquake risk level. , the magnitude of the earthquake is classified as low, and the Poisson distribution model is used to calculate the probability of earthquake occurrence. , the magnitude of the earthquake is classified as medium, and the probability of earthquake occurrence is calculated using a time-dependent model. , the magnitude of the earthquake is divided into high levels, and the probability of earthquake occurrence is calculated using a clustering model or a conditional probability model.

10. The double-bubble seismic source monitoring method based on underwater seismic detection according to claim 1, characterized in that: The S7 is based on displaying the earthquake risk level assessment results and earthquake probability results in a visual manner through an application program, thereby pushing earthquake risk information to the user terminal in real time.

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