JP-2026074648-A - Seismic wave measurement method, aging rate measurement method, program, and data processing device.

Abstract

[Challenge] To enable accurate correction of the internal time. [Solution] The data processing device 1 includes a temperature determination unit 181 that determines the seabed temperature at the location on the seabed where a measuring device is installed that creates measurement data of seismic waves associated with an internal time in which seismic waves were detected in response to vibration waves being emitted from the source of the earthquake; a temperature reduction unit 182 that lowers the temperature of an oscillator 41 built into a measuring device located outside of seawater to the seabed temperature; a rate measurement unit 183 that measures the aging rate, which is the rate of change in the frequency of the oscillator 41 over time, when the temperature of the oscillator 41 built into the measuring device located outside of seawater has reached the determined seabed temperature; and a correction unit 188 that corrects the internal time associated with the measurement data based on the aging rate after the measuring device installed on the seabed has created the measurement data. [Selection Diagram] Figure 8

Inventors

• 清水 賢
• 田中 耕太郎
• 祖父江 克也

Assignees

• サイスガジェット株式会社

Dates

Publication Date

20260507

Application Date

20241021

Claims (11)

1. A temperature determination step to determine the seabed temperature at the location on the seabed where a measuring device is installed that creates measurement data of the seismic waves associated with the internal time when the seismic waves were detected in response to the emission of seismic waves from the epicenter, A cooling step to bring the temperature of the oscillator built into the measuring device located outside of seawater to the seabed temperature, A rate measurement step in which the aging rate, which is the rate of change over time of the frequency of the oscillator, is measured when the temperature of the oscillator built into the measuring device located outside of seawater reaches the specified seabed temperature, After the measuring device installed on the seabed has created the measurement data, a correction step is performed to correct the internal time associated with the measurement data based on the aging rate, A seismic wave measurement method having [specific characteristics].
2. The measuring device located outside of seawater has a temperature change device that changes the temperature of the oscillator, In the low-temperature step, the temperature of the oscillator is controlled to change the temperature of the temperature change device so that the temperature of the oscillator becomes the seabed temperature. The seismic wave measurement method according to claim 1.
3. After performing the aforementioned low-temperature step and the rate measurement step, The steps include releasing the control over the temperature change device, After releasing the control over the temperature change device, the installation step involves installing the measuring device on the seabed. It further possesses, The seismic wave measurement method according to claim 2.
4. After performing the aforementioned low-temperature step and the rate measurement step, The method further includes an installation step of installing the measuring device on the seabed while maintaining the control over the temperature change device. The seismic wave measurement method according to claim 2.
5. Before the correction step, A time difference determination step that determines the time difference between the absolute time and the internal time of the measuring device, Installation step of installing the measuring device on the seabed, It further possesses, In the correction step, the internal time associated with the measurement data is corrected based on the time difference and the aging rate. The seismic wave measurement method according to claim 1.
6. In the correction step, based on the aging rate, the amount of time drift in the elapsed time from the first internal time, which is the internal time at the time the time difference was identified, to the second internal time associated with the measurement data is identified, and the second internal time is corrected based on the identified amount of time drift. The seismic wave measurement method according to claim 5.
7. A computer executes A temperature determination step to determine the seabed temperature at the location on the seabed where a measuring device is installed that generates measurement data of the seismic waves associated with the internal time when the seismic waves were detected in response to the emission of seismic waves from the epicenter, A cooling step to bring the temperature of the oscillator built into the measuring device located outside of seawater to the seabed temperature, A rate measurement step in which the aging rate, which is the rate of change over time of the frequency of the oscillator, is measured when the temperature of the oscillator built into the measuring device located outside of seawater reaches the specified seabed temperature, A method for measuring aging rate, comprising the following features.
8. The processor in the information processing device A temperature determination unit that determines the seabed temperature at the location on the seabed where a measuring device is installed that creates measurement data of the seismic waves associated with the internal time when the seismic waves were detected in response to the emission of seismic waves from the epicenter, A cooling unit that lowers the temperature of the oscillator built into the measuring device located outside of seawater to the seabed temperature, A rate measuring unit measures the aging rate, which is the rate of change over time of the frequency of the oscillator, when the temperature of the oscillator built into the measuring device located outside of seawater has reached the specified seabed temperature, A program designed to function as such.
9. A temperature determination unit that determines the seabed temperature at the location on the seabed where a measuring device is installed that creates measurement data of the seismic waves associated with the internal time when the seismic waves were detected in response to the emission of seismic waves from the epicenter, A cooling unit that lowers the temperature of the oscillator built into the measuring device located outside of seawater to the seabed temperature, A rate measuring unit measures the aging rate, which is the rate of change over time of the frequency of the oscillator, when the temperature of the oscillator built into the measuring device located outside of seawater has reached the specified seabed temperature, After the measuring device installed on the seabed has created the measurement data, a correction unit corrects the internal time associated with the measurement data based on the aging rate, A data processing device having
10. An oscillator used for timing the internal time, A temperature change device for changing the temperature of the oscillator, A processor that controls the temperature change device so that the temperature change device changes the temperature of the oscillator, A seismic wave measurement unit creates measurement data of the seismic waves associated with an internal time when seismic waves are detected in response to the emission of seismic waves from the epicenter, A measuring device having the following features.
11. The temperature-changing device is made of a material that absorbs heat on one side and releases the absorbed heat on the other side. The measuring device according to claim 10.

Description

This invention relates to a seismic wave measurement method, an aging rate measurement method, a program, a data processing device, and a measuring apparatus for measuring seismic waves. Since the oscillation frequency of a crystal oscillator changes over time, techniques for adjusting the oscillation frequency are known (see, for example, Patent Document 1). Japanese Patent Publication No. 2010-245978 This is a diagram illustrating the seismic wave measurement system S.This figure shows an example of the temperature change in a conventional oscillator.This diagram shows the relationship between the external device 1, the measuring device 4, and the temperature change device 5 according to the first embodiment.This is a flowchart showing the flow of the measurement method according to the first embodiment.This is a schematic diagram showing the temperature change of the oscillator during the measurement method according to the first embodiment.This is a diagram illustrating the procedure for activating multiple measuring devices 4.This figure shows an example of a management table that indicates the status of each measuring device 4.This diagram shows the configuration of the data processing device 1 according to the first embodiment.This graph shows the amount of time drift over time.This figure shows an example of a flowchart illustrating the internal time correction process according to this embodiment.This figure shows the configuration of the measuring device 4 according to the first embodiment.This is a flowchart showing the flow of the measurement method according to the second embodiment.This is a schematic diagram showing the temperature change of the oscillator during the measurement method according to the second embodiment.This figure shows the configuration of the measuring device 4 according to the second embodiment. <First Embodiment> [Overview of Measurement System S] Figure 1 shows an overview of the measurement system S. The measurement system S is an ocean geophysical exploration system for analyzing the subseafloor geological structure. In the measurement system S, vibration waves are generated from a source 2 such as an air gun or sparker, and a data processing device 1 uses the results of vibration wave measurements by numerous measuring devices 4 installed on the seabed to analyze the subseafloor geological structure. The measurement system S comprises a data processing device 1, a seismic source 2, an optical communication device 3, and a plurality of measurement devices 4. The data processing device 1, seismic source 2, and optical communication device 3 are mounted on a vessel 100 capable of navigating the ocean. The plurality of measurement devices 4 are installed on the seabed at intervals of a predetermined distance or greater. The data processing device 1 is, for example, a computer. It acquires measurement data indicating the seabed vibration state observed by multiple measuring devices 4 at the timing of seismic wave emission, and analyzes the acquired measurement data. Specifically, the data processing device 1 analyzes the seismic wave measurement data detected by the measuring devices 4 in response to seismic waves emitted from the epicenter 2 towards the seabed from a ship navigating the sea during the measurement period. As shown in Figure 1(a), the data processing device 1 controls the multiple measuring devices 4 by transmitting and receiving acoustic signals, and also receives the measurement data generated by the multiple measuring devices 4. Furthermore, the data processing device 1 acquires information indicating absolute time from, for example, a PTP network or GPS (Global Positioning System). The seismic source 2 generates vibration waves during the measurement period. The seismic source 2 generates vibration waves based, for example, on the control of the data processing device 1, but it may also generate vibration waves based on the control of a different control device (for example, a computer installed on a ship different from ship 100). The optical communication device 3 acquires measurement data from at least one measuring device 4 by communicating optically with it based on the control of the data processing device 1. The optical communication device 3 emits a first optical signal to the measuring device 4 underwater, and receives a second optical signal transmitted by the measuring device 4 that received the first optical signal. The optical communication device 3 is connected to the data processing device 1 by cable C, and, based on the control of the data processing device 1, dives to a position where it can communicate optically with the measuring device 4, and then communicates optically with the measuring device 4. The optical communication device 3 moves sequentially to the vicinity of multiple measuring devices 4 and sequentially acquires measurement data from multiple measuring devices 4. Note that the measurement system S may have multiple optica