Method for calculating depth of Moho surface of extraterrestrial body and related device

Abstract

The application discloses a method for calculating the Moho surface depth of an extraterrestrial object and a related device, and relates to the technical field of deep space exploration data processing. The method comprises the following steps: acquiring a seismic event with position information of a target extraterrestrial object, picking up an observation travel time difference T obs of a plurality of seismic body wave phases relative to a first arrival P wave cal ; constructing a plurality of seismological structure models, calculating the theoretical travel time of each seismic phase and the theoretical first arrival time of the P wave, and obtaining the theoretical travel time difference T cal of the seismic phase relative to the first arrival P wave obs ; calculating the travel time residual T res of each seismological structure model according to the theoretical travel time difference T cal and the observation travel time difference T obs ; and determining the average Moho surface depth of the event-station great circle path of the target extraterrestrial object. The application can obtain the Moho surface depth distribution in a larger area, which is helpful for understanding the geological structure, formation process and evolution mechanism of the extraterrestrial object.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of deep space exploration data processing, in particular to a method for calculating the depth of the Moho surface of an extraterrestrial body and related devices. BACKGROUND

[0002] Deep space exploration is one of the most advanced and active fields of science and technology. For a deep space exploration mission to the moon, a seismometer is usually deployed on the moon to detect the internal structure of the moon. Due to technical limitations such as limited space, limited payload weight and volume, and economic costs, only one seismometer can be deployed in a deep space exploration mission.

[0003] Moho surface discontinuity, Moho surface refers to the interface between the crust and the mantle. Obtaining the depth of the Moho surface is one of the important scientific goals of deep space exploration missions, mainly because it contains key information about the formation and evolution of the moon, Mars and other extraterrestrial bodies. By obtaining the depth of the Moho surface, the interaction between the crust and the mantle can be further understood, and the formation and evolution history of these celestial bodies can be revealed.

[0004] Currently, the main method for detecting the depth of the Moho surface is the receiver function method. This method can effectively infer the depth of the Moho surface below the seismometer by analyzing the reflection and refraction characteristics of seismic waves at the interface between the crust and the mantle. However, the receiver function method has a significant limitation, which is that it can only provide the depth of the Moho surface at the location of the seismometer, and cannot obtain the depth distribution of the Moho surface in a larger area. Due to the complex geological structure of extraterrestrial bodies such as the moon and Mars, this limitation makes it impossible to fully understand the internal structure of these celestial bodies, thereby limiting the understanding of the formation process and evolution mechanism of the moon, Mars and other extraterrestrial bodies.

[0005] Therefore, how to provide a calculation method that can obtain the depth distribution of the Moho surface in a larger area has become a technical problem to be solved in the field. SUMMARY

[0006] The purpose of the present application is to provide a method for calculating the depth of the Moho surface of an extraterrestrial body and related devices, which can obtain the depth distribution of the Moho surface in a larger area, and help to understand the geological structure, formation process and evolution mechanism of extraterrestrial bodies.

[0007] To achieve the above purpose, the present application provides the following solutions:

[0008] In a first aspect, the present application provides a method for calculating the depth of the Moho surface of an extraterrestrial body, which comprises the following steps:

[0009] acquiring a seismic event with position information of a target extraterrestrial object, picking up an observed travel time difference T of seismic body waves of a plurality of phases relative to a first arrival P wave obs ; the seismic event with position information refers to an event with position information of a hypocenter monitored by a station along an event-station great circle path.

[0010] constructing a plurality of seismological structure models according to the seismic event with position information and the observed travel time difference T obs ; each of the seismological structure models corresponds to a crustal P wave velocity value, a crustal S wave velocity value, a mantle P wave velocity value, a mantle S wave velocity value and a Moho surface depth value.

[0011] calculating a theoretical travel time of each of the phases and a theoretical P wave first arrival time based on each of the seismological structure models, to obtain a theoretical travel time difference T cal of the phases relative to the first arrival P wave.

[0012] calculating a travel time residual T cal of each of the seismological structure models according to the theoretical travel time difference T obs and the observed travel time difference T res .

[0013] determining an average Moho surface depth of the event-station great circle path of the target extraterrestrial object according to the travel time residual T res of each of the seismological structure models.

[0014] Optionally, constructing a plurality of seismological structure models according to the seismic event with position information and the observed travel time difference T obs , specifically comprising:

[0015] determining a crustal P wave velocity range, a crustal S wave velocity range, a mantle P wave velocity range, a mantle S wave velocity range and a Moho surface depth range of the target extraterrestrial object respectively according to the seismic event with position information and the observed travel time difference T obs .

[0016] discretely processing the crustal P wave velocity range, the crustal S wave velocity range, the mantle P wave velocity range, the mantle S wave velocity range and the Moho surface depth range respectively to obtain discrete crustal P wave velocity, crustal S wave velocity, mantle P wave velocity, mantle S wave velocity and Moho surface depth.

[0017] constructing a plurality of seismological structure models according to the discrete crustal P wave velocity, crustal S wave velocity, mantle P wave velocity, mantle S wave velocity and Moho surface depth.

[0018] Optionally, according to the discrete crust P-wave velocity, crust S-wave velocity, mantle P-wave velocity, mantle S-wave velocity and Moho surface depth, a plurality of seismological structure models are constructed, specifically comprising:

[0019] Randomly combine the parameter values of the discrete crust P-wave velocity, crust S-wave velocity, mantle P-wave velocity, mantle S-wave velocity and Moho surface depth, each set of parameter values randomly combined constitutes a seismological structure model, and each set of parameter values includes a crust P-wave velocity value, a crust S-wave velocity value, a mantle P-wave velocity value, a mantle S-wave velocity value and a Moho surface depth value, thereby obtaining a plurality of seismological structure models.

[0020] Optionally, during the discretization process, the velocity interval of the crust P-wave velocity, crust S-wave velocity, mantle P-wave velocity and mantle S-wave velocity is 0.1 km / s, and the interval of the Moho surface depth is 5 km.

[0021] Optionally, according to the theoretical travel time difference T cal and the observed travel time difference T obs , the travel time residual T res of each seismological structure model is calculated, and the calculation formula is:

[0022] T res = |T cal -T obs | 2 .

[0023] Optionally, according to the travel time residual T res of each seismological structure model, the average Moho surface depth of the event-station great circle path of the target extraterrestrial object is determined, specifically comprising:

[0024] The travel time residual T res of each seismological structure model is normalized and averaged, thereby obtaining the average value of the normalized travel time residual T res of each seismological structure model.

[0025] According to the average value of the normalized travel time residual T res of each seismological structure model, the average value of the normalized travel time residual T res calculated by the seismological structure model corresponding to the same Moho surface is selected.

[0026] According to the average value of the normalized travel time residual T res calculated by the seismological structure model corresponding to the same Moho surface, the normalized travel time residual Tres the minimum value in the average value of the Moho surface depth corresponding to the minimum value, as the average Moho surface depth of the event-station great circle path of the target extraterrestrial object.

[0027] Optionally, the seismic phase includes PP, SS, PPP, SSS, pP, sP and sS.

[0028] In a second aspect, a computer device is provided, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor executes the computer program to implement the extraterrestrial object Moho surface depth calculation method in any one of the above.

[0029] In a third aspect, a computer readable storage medium is provided, which stores a computer program, and the computer program is executed by a processor to implement the extraterrestrial object Moho surface depth calculation method in any one of the above.

[0030] In a fourth aspect, a computer program product is provided, which includes a computer program, and the computer program is executed by a processor to implement the extraterrestrial object Moho surface depth calculation method in any one of the above.

[0031] According to the specific embodiments provided by the present application, the following technical effects are disclosed:

[0032] The present application provides an extraterrestrial object Moho surface depth calculation method and related device, which uses the relative travel time of seismic body waves to obtain the average Moho surface depth of the event-station great circle path, and first picks up the observed travel time difference T obs of multiple seismic phases of seismic body waves relative to the first arrival P wave, and then constructs a plurality of seismological structure models to calculate the theoretical travel time difference T cal of each seismic phase relative to the first arrival P wave, so as to calculate the travel time residual T obs of each seismological structure model according to the observed travel time difference T cal and the theoretical travel time difference T res , and further can calculate the travel time residual T resThe average Moho surface depth of the event-station great circle path is determined. Compared with the traditional receiver function method, the Moho surface depth information at the position of the seismograph can be provided, and the Moho surface depth distribution in a larger regional range cannot be obtained. On the basis of the relative travel time of the seismic body wave multiple seismic phases, each set of parameters (one crust P wave velocity value, one crust S wave velocity value, one mantle P wave velocity value, one mantle S wave velocity value and one Moho surface depth value) can constitute a seismological structure model, so that each seismological structure model corresponds to a Moho surface depth, and therefore the Moho surface depth distribution in a larger regional range can be obtained, more accurate and reliable Moho surface depth results are obtained, and the geological structure, formation process and evolution mechanism of extraterrestrial celestial bodies are helpful to understand. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0034] Figure 1 An application environment diagram of the extraterrestrial celestial body Moho surface depth calculation method provided by an embodiment of the present application.

[0035] Figure 2 A flowchart of the extraterrestrial celestial body Moho surface depth calculation method provided by an embodiment of the present application.

[0036] Figure 3 A schematic diagram of the extraterrestrial celestial body Moho surface depth calculation method provided by an embodiment of the present application.

[0037] Figure 4 A schematic diagram of the extraterrestrial celestial body Moho surface depth calculation method provided by an embodiment of the present application.

[0038] Figure 5 A schematic diagram of the extraterrestrial celestial body Moho surface depth calculation method provided by an embodiment of the present application.

[0039] Figure 6 A structural schematic diagram of a computer device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0040] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts are within the scope of the present application.

[0041] The method for calculating the Moho depth of an extraterrestrial body provided by the embodiments of the present application can be applied to an application environment as shown in the figure. Figure 1 The terminal 102 communicates with the server 104 through a network. The data storage system can store data required to be processed by the server 104. The data storage system can be separately arranged, integrated on the server 104, or placed on a cloud or other servers. The terminal 102 can send the data to be processed to the server 104. After receiving the data to be processed, the server 104 obtains seismic events of a target extraterrestrial body having position information, picks up the observed travel time difference T obs of a plurality of seismic body wave phases relative to the first arrival P wave; constructs a plurality of seismological structure models; calculates the theoretical travel time of each phase and the theoretical P wave first arrival time to obtain the theoretical travel time difference T cal of the phase relative to the first arrival P wave; calculates the travel time residual T res of each seismological structure model according to the theoretical travel time difference T cal and the observed travel time difference T obs ; and determines the average Moho depth of the event-station great circle path of the target extraterrestrial body according to the travel time residual T res of each seismological structure model. The server 104 can feed back the obtained average Moho depth of the event-station great circle path to the terminal 102. In addition, in some embodiments, the method for calculating the Moho depth of an extraterrestrial body can also be implemented by the server 104 or the terminal 102 alone, for example, the terminal 102 can directly calculate the Moho depth for the data to be processed, or the server 104 can obtain the data to be processed from the data storage system and calculate the Moho depth for the data to be processed.

[0042] The terminal 102 can be, but is not limited to, various desktop computers, notebook computers, smart phones, tablet computers, Internet of Things devices, and portable wearable devices. The Internet of Things device can be a smart speaker, a smart television, a smart air conditioner, a smart vehicle device, etc. The portable wearable device can be a smart watch, a smart bracelet, a head-mounted device, etc. The server 104 can be implemented by a single server or a server cluster composed of multiple servers, and can also be a cloud server.

[0043] In one exemplary embodiment, as shown in Figure 2 Fig. 1, a method for calculating the Moho depth of an extraterrestrial body is provided, which can be applied to the scenario of calculating the Moho depth of Mars, the moon and other extraterrestrial bodies. The method is executed by a computer device, which can be a terminal or a server, or both. In the embodiments of the present application, the method is applied to the server 104 in Figure 1 Fig. 1, which includes the following steps:

[0044] Step S1, obtaining a seismic event with position information of a target extraterrestrial body, picking up the observed travel time difference T of multiple seismic phases of seismic body waves relative to the first arrival P wave obs .

[0045] In the embodiments, the target extraterrestrial body refers to an object of which the Moho depth needs to be calculated, such as Mars, the moon and other extraterrestrial bodies. The seismic event with position information refers to the position information of the event source detected by the seismic instrument of the station. The space path from the event to the station on the extraterrestrial body such as Mars or the moon is the event-station great circle path. Therefore, the seismic event with position information is the event monitored by the station on the event-station great circle path, which contains the position information of the source. The position relationship between the event and the station and the event-station great circle path are shown in Figure 3 .

[0046] The seismic phase refers to the seismic wave group with different properties or different propagation paths displayed on the seismogram. Various seismic phases have their own characteristics in arrival time, waveform, amplitude, period and particle motion mode. The characteristics of seismic phases depend on the characteristics of the source, the propagation medium and the receiving instrument. Since these wave groups have a certain duration, the waveforms of different seismic phases overlap with each other, resulting in interference, so that in general, only the beginning of the seismic phase can be identified. One of the tasks of seismology is to analyze and interpret the causes and physical meanings of various seismic phases, and to measure the basic parameters of the earthquake, study the mechanical properties of the source and explore the internal structure of the earth. When the seismic body wave reaches the surface of the extraterrestrial body, it can be reflected once or multiple times. When the reflection does not change the properties of the wave, the reflected seismic phases can be represented by PP, PPP, SS, SSS, etc. When the source is deep, the seismic body wave from the source can be reflected on the surface near the epicenter before reaching the observation point of the station, forming another seismic phase, which is called the depth phase, represented by lowercase letters such as pP, sP, sPS, etc. The arrival time difference between pP, sP and P, S is significantly affected by the change of the source depth, so these seismic phases are the main basis for determining the depth of the deep earthquake source. In the embodiments, the seismic phases include PP, SS, PPP, SSS, pP, sP and sS, etc.

[0047] Step S2, constructing a plurality of seismological structure models according to the seismic events with position information and the observed travel time difference T obs , wherein each of the seismological structure models corresponds to a crustal P-wave velocity value, a crustal S-wave velocity value, a mantle P-wave velocity value, a mantle S-wave velocity value and a Moho surface depth value.

[0048] In this embodiment, step S2 constructs a plurality of seismological structure models according to the seismic events with position information and the observed travel time difference T obs , and specifically includes the following steps:

[0049] Step S21, respectively determining a crustal P-wave velocity range, a crustal S-wave velocity range, a mantle P-wave velocity range, a mantle S-wave velocity range and a Moho surface depth range of the target extraterrestrial object according to the seismic events with position information and the observed travel time difference T obs .

[0050] Step S22, respectively performing discrete processing on the crustal P-wave velocity range, the crustal S-wave velocity range, the mantle P-wave velocity range, the mantle S-wave velocity range and the Moho surface depth range to obtain discrete crustal P-wave velocity, discrete crustal S-wave velocity, discrete mantle P-wave velocity, discrete mantle S-wave velocity and discrete Moho surface depth.

[0051] In this embodiment, when performing the discrete processing, the velocity intervals of the crustal P-wave velocity, the crustal S-wave velocity, the mantle P-wave velocity and the mantle S-wave velocity can be set as 0.1 km / s, and the interval of the Moho surface depth can be set as 5 km. The specific interval values can be set according to actual conditions.

[0052] Step S23, constructing a plurality of seismological structure models according to the discrete crustal P-wave velocity, the discrete crustal S-wave velocity, the discrete mantle P-wave velocity, the discrete mantle S-wave velocity and the discrete Moho surface depth.

[0053] In this embodiment, step S23 constructs a plurality of seismological structure models according to the discrete crustal P-wave velocity, the discrete crustal S-wave velocity, the discrete mantle P-wave velocity, the discrete mantle S-wave velocity and the discrete Moho surface depth, and specifically includes the following steps:

[0054] randomly combining the parameter values of the discrete crustal P-wave velocity, the discrete crustal S-wave velocity, the discrete mantle P-wave velocity, the discrete mantle S-wave velocity and the discrete Moho surface depth, each set of parameter values randomly combined constituting a seismological structure model, and each set of parameter values including a crustal P-wave velocity value, a crustal S-wave velocity value, a mantle P-wave velocity value, a mantle S-wave velocity value and a Moho surface depth value, to obtain a plurality of seismological structure models.

[0055] Step S3, based on each seismological structure model, calculating theoretical travel time of each seismic phase and theoretical P-wave first arrival time, to obtain theoretical travel time difference T of seismic phase relative to first arrival P-wave cal .

[0056] Step S4, according to theoretical travel time difference T cal and observed travel time difference T obs , calculating travel time residual T res of each seismological structure model.

[0057] In this embodiment, travel time residual T res of each seismological structure model is calculated by the following formula:

[0058] T res = |T cal -T obs | 2 .

[0059] Step S5, according to travel time residual T res of each seismological structure model, determining average Moho surface depth of event-station great circle path of target extraterrestrial object.

[0060] In this embodiment, step S5 determines average Moho surface depth of event-station great circle path of target extraterrestrial object according to travel time residual T res of each seismological structure model, specifically including:

[0061] Step S51, normalizing and averaging travel time residual T res of each seismological structure model to obtain average value of normalized travel time residual T res of each seismological structure model.

[0062] Step S52, according to average value of normalized travel time residual T res of each seismological structure model, selecting average value of normalized travel time residual T res calculated by the seismological structure model corresponding to the same Moho surface.

[0063] Step S53, according to average value of normalized travel time residual T res calculated by the seismological structure model corresponding to the same Moho surface, selecting Moho surface depth corresponding to minimum value (i.e. minimum normalized travel time residual T res average value) in average value of normalized travel time residual T res as average Moho surface depth of event-station great circle path of target extraterrestrial object.

[0064] In order to make the embodiment technical scheme clearer, the complete implementation process of the embodiment technical scheme will be described in the form of examples below. Specifically, the following implementation steps are included:

[0065] Step 1: Obtain seismic events with position information, pick up the travel time difference of multiple seismic body wave phases relative to the first arrival P wave, including but not limited to PP, SS, PPP, SSS, pP, sP and sS, etc., as shown in Figure 4 The travel time difference refers to the observed travel time difference, denoted as observed travel time difference T obs .

[0066] Step 2: Determine the P wave velocity range and S wave velocity range of the crust and the mantle, and the depth range of the Moho surface.

[0067] Step 3: Discretize the P wave velocity, S wave velocity of the crust and the mantle and the Moho surface depth in step 2 at certain intervals, that is, separate the value range of the above parameters according to the preset interval value, for example, the velocity interval is 0.1 km / s, and the Moho surface depth interval is 5 km.

[0068] Step 4: Each combination of parameter values of the crust P wave velocity, crust S wave velocity, mantle P wave velocity, mantle S wave velocity and Moho surface depth in step 3 constitutes a seismological structure model, that is, a seismological structure model corresponds to a crust P wave velocity, crust S wave velocity, mantle P wave velocity, mantle S wave velocity and Moho surface depth, thereby generating tens of thousands of seismological structure models.

[0069] Step 5: Based on each seismological structure model generated in step 4, calculate the theoretical travel time and theoretical P wave first arrival time of each phase in step 1, obtain the travel time difference relative to the first arrival P wave, denoted as theoretical travel time difference T cal .

[0070] Step 6: Based on the observed travel time difference T obs obtained in step 1 and the theoretical travel time difference T cal obtained in step 5, calculate the travel time residual T res of each seismological structure model cal = |T obs -T 2 .

[0071] Step 7: Since each seismological structure model corresponds to a Moho surface depth, by normalizing and averaging the travel time residuals T res of each seismological structure model obtained in step 6, the average value of the normalized travel time residuals T res calculated by the seismological structure models with the same Moho surface is selected.

[0072] Step 8: Select the travel time residual T in step 7 res The Moho depth corresponding to the minimum average value is the average Moho depth of the event-station great circle path, such as Figure 5 As shown, Figure 5 The horizontal axis represents the depth of the Moho surface, and the vertical axis represents the normalized travel time residual T res average value, Figure 5 The lowest point of the middle curve indicates the minimum normalized travel time residual T res The Moho surface depth corresponding to the average value is the final Moho surface depth result.

[0073] In this embodiment, the travel time residual T of each seismic structural model is obtained. res After that, the normalized travel time residual T can be calculated through the process of normalization and averaging. res The average value of Figure 5 The normalized travel time residual T is shown res The variation curve between the mean value and the depth of the Moho surface is then converted into the normalized travel time residual T res The Moho surface depth corresponding to the minimum value in the average value is the average Moho surface depth of the final determined event-station great circle path, which can accurately and reliably obtain the Moho surface depth result.

[0074] The present application provides a method and related device for calculating the Moho depth of an extraterrestrial body, which uses the relative travel time of multiple phases of seismic body waves to obtain the average Moho depth of the event-station great circle path. First, the observed travel time difference T of multiple phases of seismic body waves relative to the first arrival P wave is picked up. obs Then, by constructing several seismic structural models, the theoretical travel time difference T of each earthquake phase relative to the first arrival P wave is calculated. cal , so according to the theoretical travel time difference T cal and the observed travel time difference T obs , calculate the travel time residual T of each seismic structural model res , and then the travel time residual T of the seismic structural model can be used resThe average Moho surface depth of the event-station great circle path is determined. Compared with the traditional receiver function method, the Moho surface depth information of the position of the seismograph can be provided, and the Moho surface depth distribution in a larger regional range cannot be obtained. On the basis of the relative travel time of the seismic body wave multi-seismic phase, each set of parameters (one crust P wave velocity value, one crust S wave velocity value, one mantle P wave velocity value, one mantle S wave velocity value and one Moho surface depth value) can form a seismological structure model, so that each seismological structure model corresponds to a Moho surface depth, and therefore the Moho surface depth distribution in a larger regional range can be obtained, more accurate and reliable Moho surface depth results are obtained, and the geological structure, formation process and evolution mechanism of extraterrestrial celestial bodies are helpful to understand.

[0075] In an exemplary embodiment, a computer device is provided, which can be a server or a terminal, and an internal structure diagram thereof can be as shown in Figure 6 The computer device includes a processor, a memory, an input / output interface (I / O) and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store the calculation data of the Moho surface depth of extraterrestrial celestial bodies, i.e. the data to be processed. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals through network connection. The computer program is executed by the processor to implement a calculation method of the Moho surface depth of extraterrestrial celestial bodies.

[0076] Those skilled in the art can understand that Figure 6 The structure shown in the figure is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the computer device to which the scheme of the present application is applied. The specific computer device can include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0077] In an exemplary embodiment, a computer device is provided, which includes a memory and a processor, the memory stores a computer program, and the processor executes the computer program to implement the above-mentioned calculation method of the Moho surface depth of extraterrestrial celestial bodies.

[0078] In an exemplary embodiment, a computer readable storage medium storing a computer program is provided, the computer program, when executed by a processor, implements the method for calculating the Moho depth of an extraterrestrial body.

[0079] In an exemplary embodiment, a computer program product is provided, comprising a computer program, which, when executed by a processor, implements the method for calculating the Moho depth of an extraterrestrial body.

[0080] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by a computer program instructing related hardware, and the computer program can be stored in a non-volatile computer readable storage medium. When the computer program is executed, it can include the processes of the above-mentioned embodiment methods. Any reference to memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical storage, high-density embedded non-volatile memory, resistive memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration but not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0081] The technical features of the above embodiments can be combined in any manner. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described, however, as long as the combinations of the technical features do not exist contradictions, they should be considered as the scope of the present disclosure.

[0082] The principles and implementation manners of the present application are described herein by using specific examples, and the above examples are only used to help understand the method of the present application and its core idea; meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation manners and application ranges will have changes. In conclusion, the content of the specification should not be understood as a limitation of the present application.

Claims

1. A method for calculating the depth of the Moho surface of an extraterrestrial object, characterized in that: The method for calculating the depth of the Moho surface of the extraterrestrial object includes: Obtain the earthquake event with position information of the target extraterrestrial body, pick up the observed travel time difference T of multiple phases of seismic body waves relative to the first arrival P wave obs The earthquake event with location information refers to an event containing source location information monitored by a station along the event-station great circle path; According to the earthquake event with location information and the observed travel time difference T obs , constructing a plurality of seismic structure models; each of the seismic structure models corresponds to a crustal P-wave velocity value, a crustal S-wave velocity value, a mantle P-wave velocity value, a mantle S-wave velocity value and a Moho surface depth value; Based on each of the seismic structural models, the theoretical travel time and theoretical P-wave first arrival time of each seismic phase are calculated to obtain the theoretical travel time difference T of the seismic phase relative to the first arrival P wave. cal ; According to the theory, the travel time difference T cal and the observed travel time difference T obs , calculate the travel time residual T of each seismic structural model res ; According to the travel time residual T of each seismic structural model res , determine the average Moho surface depth of the event-station great circle path of the target extraterrestrial object.

2. The method for calculating the depth of the Moho surface of an extraterrestrial object according to claim 1, wherein: According to the earthquake event with location information and the observed travel time difference T obs , construct several seismic structural models, including: According to the earthquake event with location information and the observed travel time difference T obs , respectively determining the crustal P-wave velocity range, crustal S-wave velocity range, mantle P-wave velocity range, mantle S-wave velocity range and Moho surface depth range of the target extraterrestrial object; performing discretization on the crustal P-wave velocity range, the crustal S-wave velocity range, the mantle P-wave velocity range, the mantle S-wave velocity range, and the Moho surface depth range, respectively, to obtain discretized crustal P-wave velocity, crustal S-wave velocity, mantle P-wave velocity, mantle S-wave velocity, and Moho surface depth; Several seismic structure models are constructed based on the discretized crustal P-wave velocity, crustal S-wave velocity, mantle P-wave velocity, mantle S-wave velocity and Moho surface depth.

3. The method for calculating the depth of the Moho surface of an extraterrestrial object according to claim 2, wherein: According to the discretized crustal P-wave velocity, crustal S-wave velocity, mantle P-wave velocity, mantle S-wave velocity and Moho surface depth, several seismic structural models are constructed, specifically including: The discretized parameter values ​​of the crustal P-wave velocity, crustal S-wave velocity, mantle P-wave velocity, mantle S-wave velocity and Moho surface depth are randomly combined, and each group of parameter values ​​obtained by the random combination constitutes a seismic structure model, and each group of parameter values ​​includes a crustal P-wave velocity value, a crustal S-wave velocity value, a mantle P-wave velocity value, a mantle S-wave velocity value and a Moho surface depth value, thereby obtaining a plurality of seismic structure models.

4. The method for calculating the depth of the Moho surface of an extraterrestrial object according to claim 2, wherein: During the discrete processing, the velocity intervals of the crustal P-wave velocity, the crustal S-wave velocity, the mantle P-wave velocity, and the mantle S-wave velocity are 0.1 km / s, and the interval of the Moho surface depth is 5 km.

5. The method for calculating the depth of the Moho surface of an extraterrestrial object according to claim 1, characterized in that: According to the theory, the travel time difference T cal and the observed travel time difference T obs , calculate the travel time residual T of each seismic structural model res , the calculation formula is: T res =|T cal -T obs | 2 。 6. The method for calculating the depth of the Moho surface of an extraterrestrial object according to claim 1, characterized in that: According to the travel time residual T of each seismic structural model res , determining the average Moho depth of the event-station great circle path of the target extraterrestrial object, specifically comprising: The travel time residual T of each seismic structural model res Normalization and averaging are performed to obtain the normalized travel time residual T of each seismic structural model. res The average value of According to the normalized travel time residual T of each seismological structural model res The average value of the normalized travel time residual T calculated by the seismological structural model corresponding to the same Moho surface is selected res The average value of The normalized travel time residual T calculated based on the seismic structural model corresponding to the same Moho surface res The average value of the normalized travel time residual T res The Moho depth corresponding to the minimum value in the average value is taken as the average Moho depth of the event-station great circle path of the target extraterrestrial object.

7. The method for calculating the depth of the Moho surface of an extraterrestrial object according to claim 1, characterized in that: The seismic phases include PP, SS, PPP, SSS, pP, sP and sS.

8. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method for calculating the depth of the Moho surface of an extraterrestrial object according to any one of claims 1 to 7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for calculating the depth of the Moho surface of an extraterrestrial object described in any one of claims 1 to 7 is implemented.

10. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the method for calculating the depth of the Moho surface of an extraterrestrial object described in any one of claims 1 to 7 is implemented.

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