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

Abstract

The invention discloses an extraterrestrial celestial body Moho surface depth calculation method and a related device, and relates to the technical field of deep space exploration data processing, and the method comprises the steps: obtaining a seismic event with position information of a target extraterrestrial celestial body, and picking up the observation travel time difference Tobs of a plurality of seismic phases of a seismic body wave relative to a first arrival P wave; constructing a plurality of seismological structure models, calculating the theoretical travel time and the theoretical P wave first arrival time of each seismic phase, and obtaining the theoretical travel time difference Tcal of the seismic phase relative to the first arrival P wave; and according to the theoretical travel time difference Tcal and the observation travel time difference Tobs, calculating a travel time residual error Tres of each seismological structure model so as to determine the average Moho surface depth of the event-station great circle path of the target extraterrestrial celestial body. According to the method, Moho surface depth distribution in a larger area range can be obtained, and the geologic structure, the formation process and the evolution mechanism of extraterrestrial celestial bodies can be understood.

Description

Technical Field

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

[0002] Deep space exploration is one of the most cutting-edge and active areas of scientific and technological development. For deep space exploration missions 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 the limited space of the probe, limited payload weight and volume, and economic costs, only one seismometer can be deployed for a deep space exploration mission.

[0003] Moho noodles( 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, we can further understand the interaction between the crust and the mantle, and then reveal the formation and evolution history of these celestial bodies.

[0004] At present, the main method for detecting the depth of the Moho surface is the receiver function method, which 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, that is, it can only provide Moho surface depth information at the location of the seismometer, but cannot obtain the Moho surface depth distribution in a larger area. Since extraterrestrial bodies such as the moon and Mars may have complex geological structures, this limitation makes it impossible to fully understand the internal structure of these celestial bodies, thereby limiting the in-depth understanding of the formation process and evolution mechanism of extraterrestrial bodies such as the moon and Mars.

[0005] Based on this, how to provide a calculation method that can obtain the Moho surface depth distribution in a larger area has become a technical problem that needs to be solved urgently in this field. Summary of the invention

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

[0007] To achieve the above objectives, this 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, the method for calculating the depth of the Moho surface of an extraterrestrial body comprising the following steps:

[0009] Obtain the seismic events 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 the location information of the earthquake source monitored by a station along the event-station great circle path.

[0010] According to the earthquake event with location information and the observed travel time difference T obs , construct several seismic structure models; each of the seismic structure models corresponds to 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.

[0011] 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 .

[0012] 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 seismological structural model res .

[0013] According to the travel time residual T of each seismological structural model res , determine the average Moho surface depth of the event-station great circle path of the target extraterrestrial object.

[0014] Optionally, according to the earthquake event with location information and the observed travel time difference T obs , construct several seismic structural models, including:

[0015] According to the earthquake event with location information and the observed travel time difference T obs , respectively determine the crust P-wave velocity range, crust S-wave velocity range, mantle P-wave velocity range, mantle S-wave velocity range and Moho surface depth range of the target extraterrestrial object.

[0016] The crust P-wave velocity range, the crust S-wave velocity range, the mantle P-wave velocity range, the mantle S-wave velocity range and the Moho surface depth range are respectively discretized to obtain the discretized crust P-wave velocity, crust S-wave velocity, mantle P-wave velocity, mantle S-wave velocity and Moho surface depth.

[0017] 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 seismological structure models are constructed.

[0018] Optionally, 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 structure models are constructed, specifically including:

[0019] 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 ​​randomly combined 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, so as to obtain a plurality of seismic structure models.

[0020] Optionally, during the discrete processing, the velocity intervals of the crust P wave velocity, the crust 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.

[0021] Optionally, 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 seismological structural model res , the calculation formula is:

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

[0023] Optionally, 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:

[0024] 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 .

[0025] 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 .

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

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

[0028] In a second aspect, the present application provides 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 any of the above-described methods for calculating the Moho surface depth of an extraterrestrial object.

[0029] In a third aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements any of the above-described methods for calculating the Moho depth of an extraterrestrial object.

[0030] In a fourth aspect, the present application provides a computer program product, including a computer program, which, when executed by a processor, implements any of the above-mentioned methods for calculating the Moho surface depth of an extraterrestrial object.

[0031] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0032] The present application provides a method and a 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 seismic phase relative to the first-arrival P wave is calculated. cal , so according to the observed travel time difference T obs and theoretical travel jet lag T cal , 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 resDetermine the average Moho depth of the event-station great circle path. Compared with the problem that the traditional receiver function method can only provide the Moho depth information of the location of the seismograph, and cannot obtain the Moho depth distribution in a larger area, the present application is based on the relative travel time of multiple phases of seismic body waves, and each set of parameters (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) can constitute a seismological structure model, so that each seismological structure model corresponds to a Moho surface depth, so that the Moho surface depth distribution in a larger area can be obtained, and a more accurate and reliable Moho surface depth result can be obtained, which is helpful to understand the geological structure, formation process and evolution mechanism of extraterrestrial bodies. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 A diagram of the application environment of a method for calculating the depth of the Moho surface of an extraterrestrial body provided in one embodiment of the present application.

[0035] Figure 2 A flow chart of a method for calculating the depth of the Moho surface of an extraterrestrial object provided in one embodiment of the present application.

[0036] Figure 3 A schematic diagram of a seismic event, station and great circle path on Mars with location information provided in one embodiment of the present application.

[0037] Figure 4 A schematic diagram of the seismic wave paths and the positions of the Moho surfaces of different seismic phases provided in one embodiment of the present application.

[0038] Figure 5 A schematic diagram of the average Moho surface depth of an event-station great circle path provided in one embodiment of the present application.

[0039] Figure 6 A schematic diagram of the structure of a computer device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0041] The method for calculating the depth of the Moho surface of an extraterrestrial body provided in the embodiment of the present application can be applied to Figure 1 In the application environment shown. Among them, the terminal 102 communicates with the server 104 through the network. The data storage system can store the data that the server 104 needs to process. The data storage system can be set up separately, integrated on the server 104, or placed on the cloud or other servers. The terminal 102 can send the data to be processed to the server 104. After the server 104 receives the data to be processed, for the data to be processed, the server 104 obtains the seismic event with position information of the target extraterrestrial body, picks up the observed travel time difference T of multiple seismic phases of the seismic body wave relative to the first arrival P wave obs ; Construct several seismic structural models; Calculate the theoretical travel time and theoretical P-wave first arrival time of each seismic phase, and obtain the theoretical travel time difference T of the seismic phase relative to the first arrival P wave cal ; According to the theoretical travel time difference T cal and the observed travel time difference T obs , calculate the travel time residual T for each seismological structural model res ; Based on the travel time residual T of each seismic structural model res , determine the average Moho depth of the event-station great circle path of the target extraterrestrial object. 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 calculation method of the Moho depth of the extraterrestrial object can also be implemented by the server 104 or the terminal 102 alone, such as 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 may be, but is not limited to, various desktop computers, laptop computers, smart phones, tablet computers, IoT devices, and portable wearable devices. The IoT devices may be smart speakers, smart TVs, smart air conditioners, smart vehicle-mounted devices, etc. The portable wearable devices may be smart watches, smart bracelets, head-mounted devices, etc. The server 104 may be implemented as an independent server or a server cluster consisting of multiple servers, or may be a cloud server.

[0043] In an exemplary embodiment, Figure 2 As shown, a method for calculating the depth of the Moho surface of an extraterrestrial body is provided, which can be applied to the scene of calculating the depth of the Moho surface of extraterrestrial bodies such as Mars and the Moon. The method is executed by a computer device, specifically, it can be executed by a computer device such as a terminal or a server alone, or it can be executed by a terminal and a server together. In the embodiment of the present application, the method is applied to Figure 1 The server 104 in the example is used as an example to illustrate, and specifically includes the following steps:

[0044] Step S1: Obtain a seismic event with position information of the target extraterrestrial body, and pick 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 this embodiment, the target extraterrestrial object refers to the celestial object for which the Moho surface depth needs to be calculated, such as Mars, the Moon and other extraterrestrial objects. An earthquake event with location information refers to the location information of the event source detected by a seismograph or other equipment at a station. The spatial path from the event to the station on an extraterrestrial object such as Mars and the Moon is the event-station great circle path. Therefore, an earthquake event with location information is an event containing the location information of the source detected by a station on the event-station great circle path. The positional relationship between the event and the station and the event-station great circle path are as follows: Figure 3 shown.

[0046] Seismic phase refers to a group of seismic waves with different properties or different propagation paths displayed on the seismogram. Various seismic phases have their own characteristics in terms of arrival time, waveform, amplitude, period and particle motion mode. The characteristics of seismic phases depend on the characteristics of the earthquake source, propagation medium and receiving instrument. Since these wave groups have a certain duration, the waveforms of different seismic phases overlap and interfere with each other, making the seismogram present a complex picture, so that under normal circumstances, only the beginning of the seismic phase can be identified. One of the tasks of seismology is to analyze and explain the causes and physical significance of various seismic phases, and to use various seismic phase characteristics to determine the basic parameters of earthquakes, study the mechanical properties of the earthquake source and explore the internal structure of the earth. When seismic body waves are transmitted to the surface of extraterrestrial bodies, they may be reflected once or multiple times. If the properties of the waves are not changed during reflection, the reflected seismic phases can be represented by PP, PPP, SS, SSS, etc. When the earthquake source is deep, the seismic body waves emitted from the earthquake source may first be reflected on the surface near the epicenter before reaching the observation point of the station and forming another seismic phase, called the deep seismic phase, with lowercase letters representing the wave path before reflection near the epicenter, such as pP, sP, sPS, etc. The arrival time difference between pP, sP, etc. and P, S has a significant response to the change of the earthquake source depth, so these seismic phases are the main basis for determining the depth of the deep earthquake source. In this embodiment, the seismic phases include PP, SS, PPP, SSS, pP, sP and sS, etc.

[0047] Step S2: According to the earthquake event with location information and the observed travel time difference T obs , construct several seismic structure models. Each seismic structure model 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 is based on the earthquake event with location information and the observed travel time difference T obs , construct several seismic structural models, including the following steps:

[0049] Step S21: According to the earthquake event with location information and the observed travel time difference T obs , respectively determine 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.

[0050] Step S22, respectively discretize the crust P wave velocity range, crust S wave velocity range, mantle P wave velocity range, mantle S wave velocity range and Moho surface depth range to obtain the discretized crust P wave velocity, crust S wave velocity, mantle P wave velocity, mantle S wave velocity and Moho surface depth.

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

[0052] Step S23: construct several seismic structure models according to the discretized crust P-wave velocity, crust S-wave velocity, mantle P-wave velocity, mantle S-wave velocity and Moho surface depth.

[0053] In this embodiment, step S23 constructs several seismic structure models according to the discretized crust P wave velocity, crust S wave velocity, mantle P wave velocity, mantle S wave velocity and Moho surface depth, and specifically includes the following steps:

[0054] The discretized parameter values ​​of crustal P-wave velocity, crustal S-wave velocity, mantle P-wave velocity, mantle S-wave velocity and Moho surface depth are randomly combined. Each group of parameter values ​​randomly combined 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 several seismic structure models.

[0055] Step S3: Based on each seismological structural model, 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 .

[0056] Step S4: According to the theoretical travel time difference T cal and the observed travel time difference T obs , calculate the travel time residual T for each seismological structural model res .

[0057] In this embodiment, the travel time residual T of each seismic structural model is calculated using the following formula: res :

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

[0059] Step S5: Based on the travel time residual T of each seismic structural model res , determine the average Moho depth of the event-station great circle path of the target extraterrestrial object.

[0060] In this embodiment, step S5 is based on the travel time residual T of each seismic structural model. res , determine the average Moho depth of the event-station great circle path of the target extraterrestrial object, including:

[0061] Step S51: calculate 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 .

[0062] Step S52: according to the normalized travel time residual T of each seismic 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 .

[0063] Step S53: calculate the normalized travel time residual T according to the seismic structural model corresponding to the same Moho surface. res The average value of the normalized travel time residual T res The minimum value among the average values ​​(i.e. the minimum normalized travel time residual T res The Moho depth corresponding to the average value) is taken as the average Moho depth of the event-station great circle path of the target extraterrestrial object.

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

[0065] Step 1: Obtain an earthquake event with location information, and pick up the travel time differences of multiple phases of seismic body waves relative to the first-arrival P wave. These phases include but are not limited to PP, SS, PPP, SSS, pP, sP and sS, such as Figure 4 The travel time difference refers to the observed time difference, denoted as the observed travel time difference T obs .

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

[0067] Step 3: Discretize the P-wave velocity, S-wave velocity and Moho surface depth of the crust and mantle in step 2 at certain intervals, that is, separate the value ranges of the above parameters according to preset interval values, 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 the 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 seismic structure model, that is, one seismic structure model corresponds to one 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 seismic structure models.

[0069] Step 5: Based on each seismic structural model generated in step 4, calculate the theoretical travel time and theoretical P-wave first arrival time of each seismic phase in step 1, and obtain its travel time difference relative to the first arrival P wave, which is recorded as the theoretical travel time difference T cal .

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

[0071] Step 7: Since each seismic structural model corresponds to a Moho surface depth, the travel time residual T of each seismic structural model obtained in step 6 is res Normalize and average the normalized travel time residual T calculated by the seismological structural model of the same Moho surface res The average value of .

[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, through the process of normalization and averaging, the normalized travel time residual T can be calculated. res The average value of Figure 5 The normalized travel time residual T is shown res The variation curve between the average value and the Moho surface depth is then converted into the normalized travel time residual T res The Moho depth corresponding to the minimum value in the average value is the average Moho depth of the event-station great circle path finally determined, and the Moho depth result can be obtained accurately and reliably.

[0074] The present application provides a method and a 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 seismic 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 resDetermine the average Moho depth of the event-station great circle path. Compared with the problem that the traditional receiver function method can only provide the Moho depth information of the location of the seismograph, and cannot obtain the Moho depth distribution in a larger area, the present application is based on the relative travel time of multiple phases of seismic body waves, and each set of parameters (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) can constitute a seismological structure model, so that each seismological structure model corresponds to a Moho surface depth, so that the Moho surface depth distribution in a larger area can be obtained, and a more accurate and reliable Moho surface depth result can be obtained, which is helpful to understand the geological structure, formation process and evolution mechanism of extraterrestrial bodies.

[0075] In an exemplary embodiment, a computer device is provided. The computer device may be a server or a terminal. The internal structure diagram thereof may be as follows: Figure 6 As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as 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 calculated data of the Moho surface depth of an extraterrestrial body, that is, the data to be processed. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a method for calculating the Moho surface depth of an extraterrestrial body is implemented.

[0076] Those skilled in the art will understand that Figure 6 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may 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 also provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the above-mentioned method for calculating the Moho surface depth of an extraterrestrial object is implemented.

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

[0079] In an exemplary embodiment, a computer program product is provided, including a computer program, which, when executed by a processor, implements the above-mentioned method for calculating the Moho surface depth of an extraterrestrial object.

[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 instructing the relevant hardware through a computer program, 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 embodiments of the above-mentioned methods. Among them, any reference to the 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 memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM may be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0081] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0082] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A method for calculating the depth of the Moho surface of an extraterrestrial body, characterized in that: The calculation method of the Moho depth of the extraterrestrial object includes: Obtain the seismic events 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 several seismic structure models; each of the seismic structure models corresponds to 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; 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 seismological structural model res ; According to the travel time residual T of each seismological 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, characterized in that: 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 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 body; Respectively discretizing the crust P wave velocity range, the crust S wave velocity range, the mantle P wave velocity range, the mantle S wave velocity range and the Moho surface depth range to obtain discretized crust P wave velocity, crust S wave velocity, mantle P wave velocity, mantle S wave velocity and Moho surface depth; 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 seismological structure models are constructed.

3. The method for calculating the depth of the Moho surface of an extraterrestrial object according to claim 2, characterized in that: 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 structure 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 ​​randomly combined 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, so as to obtain 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, characterized in that: During the discrete processing, the velocity intervals of the crust P wave velocity, the crust 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 seismological 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 seismological 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 according to the seismological structural model corresponding to the same Moho surface res The average value of the normalized travel time residual T res The Moho surface depth corresponding to the minimum value in the average value is taken as the average Moho surface 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 Moho depth of an extraterrestrial object described in 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 Moho surface depth 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 Moho surface depth of an extraterrestrial object described in any one of claims 1 to 7 is implemented.

Images