JP7533767B2 - Earthquake monitoring device, earthquake monitoring method, and program - Google Patents

Description

The present invention relates to an earthquake monitoring device and an earthquake monitoring method for monitoring an earthquake source, and further to a program for implementing these.

When an earthquake occurs, seismometers at observation points close to the epicenter measure the shaking. However, during the same time period, seismometers at observation points far from the epicenter may also measure shaking due to noise such as ambient vibrations or electromagnetic waves. In such cases, they may mistakenly believe that a wide area is shaking, and erroneously report that a huge earthquake has occurred. Therefore, it is necessary to prevent false alarms when false shaking due to noise is observed.

According to related technology disclosed in Patent Document 1, an earthquake warning server receives earthquake report messages from user devices present in a geographic grid for each area (geographic grid) set by dividing a map. The earthquake warning server also monitors the number of earthquake report messages for each geographic grid at a preset time interval. A geographic grid for which the number of earthquake report messages within a time interval exceeds a threshold is then determined to be a candidate earthquake geographic grid. The earthquake warning server then determines an earthquake grid from among the candidate earthquake grids based on the adjacency relationship of the candidate earthquake grids.

JP 2020-052055 A

However, the earthquake warning server in Patent Document 1 is not a device that identifies the magnitude of an earthquake using a seismometer installed at an observation point. The earthquake warning server in Patent Document 1 is a device that determines a geographic grid (seismic grid) that includes the epicenter based on an earthquake report message sent by a user device such as a smartphone or tablet computer.

Furthermore, since the earthquake warning server in Patent Document 1 determines earthquake grids based on the adjacency relationships of candidate earthquake grids, if the size of the geographic grid is not set appropriately, the candidate earthquake grids cannot be selected.

One aspect of the present invention is to provide an earthquake monitoring device, an earthquake monitoring method, and a program that accurately calculate the epicenter and/or magnitude of an earthquake while eliminating erroneous observation results caused by noise.

In order to achieve the above object, an earthquake monitoring device according to one aspect includes:
a determination unit that, when shaking is observed at two or more densely-deployed observation points within a same earthquake determination time period during which the same earthquake can be deemed to have occurred, determines whether or not there is an adjacent observation point that observed shaking for each of the two or more observation points that observed shaking;
A calculation unit that calculates an epicenter and/or an earthquake magnitude using the observation results of each of the adjacent observation points;
The present invention is characterized by having the following.

In order to achieve the above object, an earthquake monitoring method according to one aspect includes:
a determination step of, when shaking is observed at two or more densely-deployed observation points within a same earthquake determination time period during which the same earthquake can be considered to have occurred, determining whether or not there is an adjacent observation point that observed shaking for each of the two or more observation points that observed shaking;
A calculation step of calculating an epicenter and/or an earthquake magnitude using the observation results of each of the adjacent observation points;
The present invention is characterized by having the following.

Furthermore, in order to achieve the above object, the program in one aspect comprises:
On the computer,
a determination step of, when shaking is observed at two or more densely-deployed observation points within a same earthquake determination time period during which the same earthquake can be considered to have occurred, determining whether or not there is an adjacent observation point that observed shaking for each of the two or more observation points that observed shaking;
A calculation step of calculating an epicenter and/or an earthquake magnitude using the observation results of each of the adjacent observation points;
The present invention is characterized in that the above-mentioned is executed.

One aspect is that it is possible to accurately calculate the epicenter and/or magnitude of an earthquake by eliminating erroneous observation results caused by noise.

FIG. 1 is a diagram for explaining an example of an earthquake monitoring device. FIG. 2 is a diagram for explaining an example of a system having an earthquake monitoring device. FIG. 3 is a diagram showing the locations of seismometers installed in Japan and its surrounding areas. FIG. 4 is a diagram for explaining an example of the operation of the earthquake monitoring device. FIG. 5 is a diagram for explaining an example of a computer that realizes an earthquake monitoring device.

Hereinafter, the embodiments will be described with reference to the drawings. In the drawings described below, elements having the same or corresponding functions are denoted by the same reference numerals, and repeated description of such elements may be omitted.

(Embodiment)
The configuration of an earthquake monitoring device 10 according to an embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram for explaining an example of an earthquake monitoring device.

[Device configuration]
The earthquake monitoring device 10 shown in Fig. 1 accurately calculates the epicenter and/or earthquake magnitude by eliminating erroneous measurement results of the seismometer caused by noise such as vibrations or electromagnetic waves around the seismometer. As shown in Fig. 1, the earthquake monitoring device 10 has a determination unit 11 and a calculation unit 12.

When shaking is observed at two or more densely-deployed observation points within the same earthquake judgment time during which the same earthquake can be deemed to have occurred, the judgment unit 11 judges, for each of the two or more observation points at which shaking was observed, whether or not there is an adjacent observation point at which shaking was observed.

Adjacent observation points are, for example, observation points that can be considered to be adjacent to an observation point, and are set in advance by the user for each observation point. Alternatively, the closest observation point to the observation point, which exists within a preset adjacent distance from the observation point , may be considered to be an adjacent observation point. The adjacent distance is determined by experiment or simulation.

High density means that the number of observation points deployed in a predetermined range is equal to or greater than the predetermined number. In contrast, low density means that the number of observation points deployed in a predetermined range is less than the predetermined number.

The calculation unit 12 calculates the epicenter and earthquake scale (magnitude), or either one, using the observation results of each observation point determined to be adjacent.

The calculation of the epicenter or earthquake scale will be done using existing calculation methods. For example, in overseas countries where the quality of seismometers is low, it may be possible to apply a comprehensive monitoring system for seismic activity, etc., as shown in "Technical Reference Material on the Overview and Processing Methods of Emergency Earthquake Alerts," Earthquake and Volcano Department, Japan Meteorological Agency, July 29, 2008, to calculate the epicenter and earthquake scale (magnitude). This technology may also be adopted in Japan if there are situations where noise interference occurs frequently.

When an earthquake occurs, the shaking spreads out like concentric spheres around the epicenter. Therefore, theoretically, the observation point closest to the epicenter (the first observation point) will observe the shaking first, followed by the observation points adjacent to the first observation point.

Therefore, if shaking is observed at non-adjacent observation points within the same earthquake determination time, it is determined to be noise (or a different earthquake) and is excluded from the observation results used to calculate the epicenter or earthquake magnitude.

This makes it possible to eliminate erroneous measurement results from the seismometer caused by noise such as vibrations or electromagnetic waves around the seismometer, and to accurately calculate the epicenter and/or magnitude of the earthquake.

Furthermore, it will be possible to prevent noise occurring around the time of the earthquake from being mistaken for shaking from the same earthquake and mistakenly reporting the occurrence of a major earthquake.

[System configuration]
The configuration of the earthquake monitoring device 10 in the embodiment will be described in more detail with reference to Fig. 2. Fig. 2 is a diagram for explaining an example of a system including the earthquake monitoring device 10.

As shown in Figure 2, the system in the embodiment has an earthquake monitoring device 10, a plurality of seismometers 20, and a network 30. The earthquake monitoring device 10 has an acquisition unit 13, a determination unit 11, and a calculation unit 12.

The earthquake monitoring device 10 is, for example, an information processing device such as a CPU (Central Processing Unit), a programmable device such as an FPGA (Field-Programmable Gate Array), or a GPU (Graphics Processing Unit), or a circuit equipped with any one or more of these, a server computer, or a personal computer.

The earthquake monitoring device 10 is connected to multiple seismometers 20 via a network 30.

When an earthquake occurs, the seismometer 20 detects seismic waves and outputs seismic wave information representing the amplitude of the seismic waves. In an embodiment, the seismic wave information may be information representing only the amplitude of the seismic waves, or information representing the amplitude and waveform of the seismic waves.

Figure 3 is a diagram showing the locations of seismometers installed in Japan and its surrounding areas. In the example of Figure 3, the locations where seismometers 20 are installed are indicated by ● (black circles). Also, in the example of Figure 3, the locations of epicenters 31, 32 are indicated by × (crosses). In the example of Figure 3, Japan is used, but it is not limited to Japan and can be anywhere other than Japan.

Network 30 is a network constructed using communication lines such as the Internet, a LAN (Local Area Network), a dedicated line, a telephone line, an in-house network, a mobile communication network, Bluetooth (registered trademark), or Wi-Fi (Wireless Fidelity).

The earthquake monitoring device will now be described.
When an earthquake occurs, the acquisition unit 13 acquires seismic wave information from the seismometer 20 via the network 30. The acquisition unit 13 then outputs the seismic wave information to the determination unit 11. The acquisition unit 13 is, for example, a communication device that communicates with the seismometer 20 via a wired or wireless connection.

In addition, the acquisition unit 13 may also acquire information that has been erroneously measured due to noise as seismic wave information.

The determination unit 11 first acquires earthquake wave information from the acquisition unit 13. Next, when the determination unit 11 acquires earthquake wave information (when shaking is observed), it executes earthquake determination processing. Note that when shaking is not observed, the determination unit 11 waits for the next earthquake wave information.

The earthquake determination process will be described.
3, the seismometers 20 are deployed at a high density in inland areas, whereas the seismometers 20 are deployed at a low density in island areas.

When an earthquake occurs, the observation point closest to the epicenter is the first to observe the shaking. Theoretically, the observation point adjacent to the observation point that experienced the shaking first will then experience the shaking. Then, like ripples spreading, the shaking should be observed at neighboring observation points one after another.

Therefore, (1) if no shaking is observed at the second observation point even after a preset same earthquake judgment time (the time during which the same earthquake can be considered to have occurred) has elapsed after the first observation point observes shaking, the judgment unit 11 judges that the shaking observed at the first observation point is not due to an earthquake (judges it as noise).

However, (2) if the first observation point is deployed at a low density, i.e., in an island area, the determination unit 11 determines that the shaking observed by the first observation point is due to an earthquake. However, if, within the same earthquake determination time, there is no observation point adjacent to the first observation point that observed shaking after the first observation point observed shaking, the observation result of the first observation point is deleted.

In addition, (3) when shaking is observed at a second observation point within the same earthquake judgment time, if the first and second observation points are adjacent to each other, the judgment unit 11 judges that the shaking observed at the first and second observation points is shaking caused by an earthquake.

(4) In addition, if shaking is observed at three or more observation points within the same earthquake judgment time and those observation points are adjacent to any observation point that has already observed shaking, the judgment unit 11 judges the shaking observed by the adjacent observation points to be shaking caused by an earthquake.

In addition, (5) if shaking is observed at a second observation point within the same earthquake judgment time, if the second observation point is not adjacent to the first observation point and further, if the second observation point is deployed at a low density, the judgment unit 11 waits for observation from a third observation point.

Then, if shaking is observed at a third observation point within the same earthquake judgment time, and if the third observation point is deployed at a low density and is adjacent to an observation point that has already observed shaking, the judgment unit 11 judges the shaking observed at the third observation point to be shaking caused by an earthquake.

Furthermore, (6) if shaking is observed at four or more observation points within the same earthquake judgment time and those observation points are adjacent to any observation point that has already observed shaking, the judgment unit 11 judges that the shaking observed at those observation points is shaking caused by an earthquake.

Also, (7) if shaking is observed at three or more observation points within the same earthquake judgment time and those observation points are not adjacent to any of the observation points that have already observed shaking, the judgment unit 11 waits for observation by a fourth observation point.

Then, if shaking is observed at a fourth observation point within the same earthquake judgment time, and if the fourth observation point is deployed at a low density and is not adjacent to an observation point that has already observed shaking, the judgment unit 11 determines the farthest observation point based on the positions of the four or more observation points, and judges that the shaking observed by the farthest observation point is not due to an earthquake (judges it as noise).

If there are four observation points, the farthest observation point is determined as shown in Equation 1. That is, the determination unit 11 calculates the sum of the relative distances for each of the four points. The determination unit 11 then determines the observation point with the largest sum as the farthest observation point.

Relative distance is the sum of the distances between the target observation point and observation points other than the target observation point. For example, if the target observation point is the first point, the relative distance is the sum of the distance between the first point and the second point, the distance between the first point and the third point, and the distance between the first point and the fourth point.

(Number 1)
max(LP1, LP2, LP3, LP4)
LP1=L_P12+L_P13+L_P14
LP2=L_P21+L_P23+L_P24
LP3=L_P31+L_P32+L_P34
LP4=L_P41+L_P42+L_P43

max(): A function to calculate the maximum value
LP1: Relative distance of the first point
LP2: Relative distance of the second point
LP3: Relative distance of the third point
LP4: Relative distance of the fourth point
L_P12, L_P21: Distance between the first and second points
L_P13, L_P31: Distance between the first and third points
L_P14, L_P41: Distance between the first and fourth points
L_P23, L_P32: Distance between the second and third points
L_P24, L_P42: Distance between the second and fourth points
L_P34, L_P43: Distance between the third and fourth points

The reason for determining it as noise is that it is extremely rare for four or more sparsely-spaced observation points to observe vibrations that are not all adjacent to one another. Therefore, the farthest observation point is determined based on the positions of four or more observation points, and the vibrations observed by the farthest observation point are determined to be noise.

In addition, (8) if shaking is observed at a second observation point within the same earthquake judgment time, and the second observation point is not adjacent to the first observation point and furthermore, if the second observation point is deployed at a high density, observations from a third observation point will be awaited.

In the case where shaking is observed at three or more observation points within the same earthquake judgment time and none of the three points are adjacent, and if three or more observation points are densely deployed, the judgment unit 11 determines the farthest observation point based on the positions of the three points, and judges that the shaking observed by the farthest observation point is not due to an earthquake (judges it as noise). The farthest observation point is determined as shown in Equation 1.

The reason for determining it as noise is that it is extremely rare for three or more densely-spaced observation points to observe vibrations that are not all adjacent to each other, so based on the locations of three or more observation points, the vibrations observed by the farthest observation point are determined to be noise.

After making the noise judgment described above, if it is within the same earthquake judgment time, the observation points other than the one judged as noise will remain, and the judgment will continue until the next observation point observes shaking.

As described above, the judgment unit 11 removes noise from the observation results by executing the earthquake judgment process shown in (1) to (8).

When there is an observation point determined to be adjacent, the calculation unit 12 calculates the epicenter and earthquake magnitude, or either one of them, using the observation results of the observation point determined to be adjacent.

Specifically, the calculation unit 12 first acquires the observation results observed by the determination unit 11. Next, the calculation unit 12 calculates the epicenter and/or earthquake magnitude based on the acquired observation results for one or more observation points through general processing.

In Figure 2, the calculation unit 12 is provided inside the earthquake monitoring device 10, but it may also be provided outside the earthquake monitoring device 10.

[Device Operation]
Next, the operation of the device in the embodiment of the invention will be described with reference to Fig. 4. Fig. 4 is a diagram for explaining an example of the operation of the earthquake monitoring device. In the following description, the diagram will be referred to as appropriate. Also, in the embodiment, the earthquake monitoring method is implemented by operating the earthquake monitoring device. Therefore, the description of the earthquake monitoring method in the embodiment will be replaced with the following description of the operation of the earthquake monitoring device.

The earthquake determination process (1) and (2) will now be described.
Specifically, when the acquisition unit 13 first acquires seismic wave information from the seismometer 20 at the first observation point (when shaking is observed) (Step A1: Yes), the judgment unit 11 judges whether the shaking is observed at two or more observation points (Step A2).

If shaking is observed only at the first observation point (step A2: No), seismic wave information cannot be obtained from the second observation point even after the same earthquake judgment time has elapsed, and it is determined whether the first observation point is deployed at a low density (step A3).

If the first observation point is deployed at a low density (step A3: Yes), the judgment unit 11 judges that the shaking observed at the first observation point is shaking caused by an earthquake (step A4).

If the first observation point is deployed at a high density (step A3: No), the judgment unit 11 judges that the shaking observed at the first observation point is not caused by an earthquake (judges it as noise) (step A11).

After that, if it is within the same earthquake judgment time, the system waits for further seismic wave information from the seismometer 20 at the observation point (Step A5: Yes).

The earthquake determination process (3) will now be described.
Specifically, if a second observation point observes shaking within the same earthquake judgment time (step A2: Yes), the judgment unit 11 judges whether the first observation point and the second observation point are adjacent to each other (step A6). If the first and second observation points are adjacent to each other (step A6: Yes), the judgment unit 11 judges that the shaking observed by the first and second observation points is shaking caused by an earthquake (step A4).

After that, if it is within the same earthquake judgment time, the system waits for further seismic wave information from the seismometer 20 at the observation point (Step A5: Yes).

The earthquake determination process (4) will now be described.
Specifically, if shaking is observed at three or more observation points within the same earthquake judgment time (step A2: Yes), and in step A6, those observation points are adjacent to any of the observation points that have already observed shaking (step A6: Yes), the judgment unit 11 judges that the shaking observed at the adjacent observation points is shaking caused by an earthquake (step A4).

The earthquake determination process (5) will now be described.
Specifically, if shaking is observed at a second observation point within the same earthquake judgment time (Step A2: Yes), if the second observation point is not adjacent to the first observation point (Step A6: No), and further if the second observation point is deployed at a low density (Step A7: Yes), the judgment unit 11 proceeds to Step A1 and waits for observation from a third observation point (Step A8: No → Step A10: No).

Next, if shaking is observed at a third observation point within the same earthquake judgment time (step A2: Yes), and if the third observation point is deployed at a low density (step A7: Yes) and is adjacent to an observation point that has already observed shaking (step A8: Yes), the judgment unit 11 judges that the shaking observed at the third observation point is shaking caused by an earthquake (step A4).

The earthquake determination process (6) will now be described.
Specifically, if shaking is observed at four or more observation points within the same earthquake judgment time (Step A2: Yes), and those observation points are adjacent to any observation point that has already observed shaking (Step A6: Yes), the judgment unit 11 judges that the shaking observed at those observation points is shaking caused by an earthquake (Step A4).

The earthquake determination process (7) will now be described.
Specifically, if shaking is observed at three or more observation points within the same earthquake judgment time, and those observation points are not adjacent to any of the observation points that have already observed shaking (step A8: No), the judgment unit 11 waits for observation from a fourth observation point (step A10: No).

Then, if shaking is observed at a fourth observation point within the same earthquake judgment time, and the fourth observation point is deployed at a low density (step A7: Yes) and is not adjacent to an observation point that has already observed shaking (step A8: No), the judgment unit 11 determines the farthest observation point based on the positions of the four or more observation points, and judges that the shaking observed by the farthest observation point is not due to an earthquake (judges it as noise) (step A11).

After that, if it is within the same earthquake judgment time, the system waits for further seismic wave information from the seismometer 20 at the observation point (Step A5: Yes).

The earthquake determination process (8) will now be described.
Specifically, if shaking is observed at a second observation point within the same earthquake judgment time (step A2: Yes), the second observation point is not adjacent to the first observation point (step A6: No), and further, if the second observation point is deployed at a high density (step A7: No, step A9: No), the system waits for observations from a third observation point.

Then, if shaking is observed at three or more observation points within the same earthquake judgment time (Step A2: Yes), and if the three or more observation points are deployed at a high density (Step A7: No, Step A9: Yes), the judgment unit 11 determines the farthest observation point based on the positions of the three or more observation points, and judges that the shaking observed by the farthest observation point is not due to an earthquake (judges it as noise) (Step A11).

After that, if it is within the same earthquake judgment time, the system waits for further seismic wave information from the seismometer 20 at the observation point (Step A5: Yes).

As described above, after the determination unit 11 executes the earthquake determination process shown in (1) to (8), if there is an observation point determined to be adjacent, the calculation unit 12 calculates the epicenter and/or earthquake magnitude using the observation results of the observation point determined to be adjacent (step A12).

Specifically, in step A12, the calculation unit 12 first acquires the observation results observed by the determination unit 11. Next, the calculation unit 12 calculates the epicenter and/or earthquake magnitude based on the acquired observation results for one or more observation points.

[Effects of this embodiment]
When an earthquake occurs, the shaking spreads like concentric spheres around the epicenter. Therefore, theoretically, the observation point closest to the epicenter (the first observation point) will observe the shaking first, followed by the observation points adjacent to the first observation point.

Therefore, if shaking is observed at non-adjacent observation points within the same earthquake judgment time, it is judged to be noise (or a different earthquake) and is excluded from the observation results used to calculate the epicenter or earthquake magnitude.

This makes it possible to eliminate erroneous measurement results from the seismometer caused by noise such as vibrations or electromagnetic waves around the seismometer, and to accurately calculate the epicenter and/or magnitude of the earthquake.

Furthermore, it can prevent noise occurring around the time of an earthquake from being mistaken for shaking from the same earthquake and mistakenly reporting a major earthquake as having occurred, as well as preventing noise information alone from being mistaken for an earthquake and reporting it as such.

[program]
The program in the embodiment of the present invention may be a program that causes a computer to execute steps A1 to A12 shown in Fig. 4. By installing and executing this program in a computer, the earthquake monitoring device and earthquake monitoring method in the embodiment can be realized. In this case, the processor of the computer functions as the acquisition unit 13, the determination unit 11, and the calculation unit 12 and performs processing.

In addition, the program in this embodiment may be executed by a computer system constructed by multiple computers. In this case, for example, each computer may function as either the acquisition unit 13, the determination unit 11, or the calculation unit 12.

[Physical configuration]
Here, a computer that realizes an earthquake monitoring device by executing a program in the embodiment will be described with reference to Fig. 5. Fig. 5 is a diagram for explaining an example of a computer that realizes the earthquake monitoring device in the embodiment of the present invention.

5, the computer 110 includes a CPU (Central Processing Unit) 111, a main memory 112, a storage device 113, an input interface 114, a display controller 115, a data reader/writer 116, and a communication interface 117. These components are connected to each other via a bus 121 so as to be able to communicate data with each other. The computer 110 may include a GPU or an FPGA in addition to or instead of the CPU 111.

The CPU 111 expands the program (code) in this embodiment stored in the storage device 113 into the main memory 112 and executes these in a predetermined order to perform various calculations. The main memory 112 is typically a volatile storage device such as a DRAM (Dynamic Random Access Memory). The program in this embodiment is provided in a state stored in a computer-readable recording medium 120. The program in this embodiment may be distributed over the Internet connected via the communication interface 117. The recording medium 120 is a non-volatile recording medium.

Specific examples of the storage device 113 include a hard disk drive and a semiconductor storage device such as a flash memory. The input interface 114 mediates data transmission between the CPU 111 and input devices 118 such as a keyboard and a mouse. The display controller 115 is connected to the display device 119 and controls the display on the display device 119.

The data reader/writer 116 mediates data transmission between the CPU 111 and the recording medium 120, reads programs from the recording medium 120, and writes the results of processing in the computer 110 to the recording medium 120. The communication interface 117 mediates data transmission between the CPU 111 and other computers.

Specific examples of recording medium 120 include general-purpose semiconductor storage devices such as CF (Compact Flash (registered trademark)) and SD (Secure Digital), magnetic recording media such as a flexible disk, or optical recording media such as a CD-ROM (Compact Disk Read Only Memory).

In addition, the earthquake monitoring device 10 in the embodiment can be realized by using hardware corresponding to each part, rather than a computer on which a program is installed. Furthermore, the earthquake monitoring device 10 may be realized in part by a program and the remaining part by hardware.

[Additional Notes]
The following supplementary notes are further disclosed regarding the above-described embodiments. A part or all of the above-described embodiments can be expressed by (Supplementary Note 1) to (Supplementary Note 18) described below, but are not limited to the following descriptions.

(Appendix 1)
a determination unit that, when shaking is observed at two or more densely-deployed observation points within a same earthquake determination time period during which the same earthquake can be deemed to have occurred, determines whether or not there are two or more adjacent observation points that observed shaking for each of the two or more observation points that observed shaking;
A calculation unit that calculates an epicenter and/or an earthquake magnitude using the observation results of each of the adjacent observation points;
An earthquake monitoring device having:

(Appendix 2)
2. The earthquake monitoring device according to claim 1,
This earthquake monitoring device is configured so that if no shaking is observed at a second observation point even after the same earthquake judgment time has elapsed after the first observation point observes shaking, the judgment unit judges that the shaking observed at the first observation point is not caused by an earthquake.

(Appendix 3)
3. The earthquake monitoring device according to claim 2,
The earthquake monitoring device, wherein when the first observation point is deployed at a low density, the determination unit determines that the shaking observed at the first observation point is caused by an earthquake.

(Appendix 4)
4. The earthquake monitoring device according to claim 2,
An earthquake monitoring device in which, when shaking is observed at the second observation point within the same earthquake judgment time, if the first observation point and the second observation point are adjacent to each other, the judgment unit judges the shaking observed at the first observation point and the second observation point to be shaking caused by an earthquake.

(Appendix 5)
5. The earthquake monitoring device according to claim 4,
The judgment unit observes shaking at three or more observation points within the same earthquake judgment time period, and if those observation points are adjacent to any of the observation points that have already observed shaking, judges the shaking observed by those observation points to be shaking caused by an earthquake.

(Appendix 6)
5. The earthquake monitoring device according to claim 4,
The determination means is
Observe shaking at three or more observation points within the same earthquake judgment time, and if those observation points are not adjacent to any of the observation points that have already observed shaking, wait for observation by a fourth observation point;
When shaking is observed at the fourth observation point within the same earthquake judgment time, if the fourth observation point is deployed at a low density and is not adjacent to an observation point which has already observed shaking, an earthquake monitoring device determines the farthest observation point based on the positions of the four observation points, and judges that the shaking observed at the farthest observation point is not caused by an earthquake.

(Appendix 7)
a determination step of, when shaking is observed at two or more densely-deployed observation points within a same earthquake determination time period during which the same earthquake can be considered to have occurred, determining whether or not there are two or more adjacent observation points that observed shaking for each of the two or more observation points that observed shaking;
A calculation step of calculating an epicenter and/or an earthquake magnitude using the observation results of each of the adjacent observation points;
The earthquake monitoring method includes:

(Appendix 8)
8. The earthquake monitoring method according to claim 7, further comprising:
The earthquake monitoring method, in which, if no shaking is observed at a second observation point even after the same earthquake judgment time has elapsed after the first observation point observes shaking, the shaking observed at the first observation point is judged to be not caused by an earthquake.

(Appendix 9)
9. The earthquake monitoring method according to claim 8, further comprising:
The earthquake monitoring method, wherein the determining step determines that the shaking observed at the first observation point is caused by an earthquake when the first observation point is deployed at a low density.

(Appendix 10)
10. The earthquake monitoring method according to claim 8, further comprising:
The earthquake monitoring method, in which the determination step determines that, when shaking is observed at the second observation point within the same earthquake determination time, the shaking observed at the first observation point and the second observation point are adjacent to each other, is caused by an earthquake.

(Appendix 11)
11. The earthquake monitoring method according to claim 10, further comprising:
The judgment step observes shaking at three or more observation points within the same earthquake judgment time, and if those observation points are adjacent to any of the observation points that have already observed shaking, judges the shaking observed by those observation points to be shaking caused by an earthquake. This is an earthquake monitoring method.

(Appendix 12)
11. The earthquake monitoring method according to claim 10, further comprising:
The determining step includes:
Observe shaking at three or more observation points within the same earthquake judgment time, and if those observation points are not adjacent to any of the observation points that have already observed shaking, wait for observation by a fourth observation point;
When shaking is observed at the fourth observation point within the same earthquake judgment time, if the fourth observation point is deployed at a low density and is not adjacent to an observation point which has already observed shaking, the earthquake monitoring method determines the farthest observation point based on the positions of the four observation points, and judges that the shaking observed at the farthest observation point is not caused by an earthquake.

(Appendix 13)
On the computer,
a determination step of, when shaking is observed at two or more densely-deployed observation points within a same earthquake determination time period during which the same earthquake can be considered to have occurred, determining whether or not there are two or more adjacent observation points that observed shaking for each of the two or more observation points that observed shaking;
A calculation step of calculating an epicenter and/or an earthquake magnitude using the observation results of each of the adjacent observation points;
A program that contains instructions to execute a program.

(Appendix 14)
14. The program according to claim 13,
The program characterized in that the judgment step judges that the shaking observed at a first observation point is not caused by an earthquake if no shaking is observed at a second observation point even after the same earthquake judgment time has elapsed after the first observation point observes shaking.

(Appendix 15)
15. The program according to claim 14,
The program , characterized in that the determination step determines that the shaking observed at the first observation point is caused by an earthquake when the first observation point is deployed at a low density.

(Appendix 16)
16. The program according to claim 14 or 15,
The program characterized in that the judgment step judges that when shaking is observed at the second observation point within the same earthquake judgment time, if the first observation point and the second observation point are adjacent to each other, the shaking observed at the first observation point and the second observation point is caused by an earthquake.

(Appendix 17)
17. The program of claim 16,
The determination step is a program characterized in that shaking is observed at three or more observation points within the same earthquake determination time, and if those observation points are adjacent to any of the observation points that have already observed shaking, the program determines that the shaking observed at those observation points is shaking caused by an earthquake.

(Appendix 18)
17. The program of claim 16,
The determining step includes:
Observe shaking at three or more observation points within the same earthquake judgment time, and if those observation points are not adjacent to any of the observation points that have already observed shaking, wait for observation by a fourth observation point;
When shaking is observed at the fourth observation point within the same earthquake judgment time, if the fourth observation point is deployed at a low density and is not adjacent to an observation point which has already observed shaking, the program determines the farthest observation point based on the positions of the four observation points, and judges that the shaking observed at the farthest observation point is not caused by an earthquake.

Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the above-mentioned embodiments. Various modifications that can be understood by a person skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

As described above, according to the present invention, it is possible to accurately calculate the epicenter and/or earthquake magnitude while eliminating erroneous observation results caused by noise. The present invention is useful in fields where it is necessary to estimate the epicenter and earthquake magnitude of an earthquake.

REFERENCE SIGNS LIST 10 Earthquake monitoring device 11 Determination unit 12 Calculation unit 13 Acquisition unit 20 Seismometer 30 Network 110 Computer 111 CPU
112 Main memory 113 Storage device 114 Input interface 115 Display controller 116 Data reader/writer 117 Communication interface 118 Input device 119 Display device 120 Recording medium 121 Bus

Claims (6)

a determination means for determining, when shaking is observed at two or more observation points deployed in a high-density range where the number of observation points deployed in a predetermined range is equal to or greater than a predetermined number , within a same earthquake determination time during which the same earthquake can be deemed to have occurred, for each of the two or more observation points at which shaking was observed, whether or not there are two or more observation points that can be deemed to be adjacent to each other at which shaking was observed;
A calculation means for calculating an epicenter and/or an earthquake magnitude using the observation results of each of the observation points considered to be adjacent to each other,
Furthermore, when shaking cannot be observed at a second observation point even after the same earthquake judgment time has elapsed after a first observation point observes shaking, the judgment means judges that the shaking observed at the first observation point is not caused by an earthquake,
When the first observation point is deployed in a low-density range where the number of the observation points deployed in a predetermined range is less than the predetermined number, the shaking observed by the first observation point is determined to be shaking caused by an earthquake.
Earthquake monitoring equipment. 2. The earthquake monitoring device according to claim 1 ,
The judgment means judges that the shaking observed at the first observation point and the second observation point is caused by an earthquake if the first observation point and the second observation point are regarded as adjacent when shaking is observed at the second observation point within the same earthquake judgment time. The earthquake monitoring device according to claim 2 ,
The judgment means observes shaking at three or more observation points within the same earthquake judgment time, and if those observation points are deemed to be adjacent to any of the observation points that have already observed shaking, judges the shaking observed by those observation points to be shaking caused by an earthquake. The earthquake monitoring device according to claim 2 ,
The determination means is
If shaking is observed at three or more observation points within the same earthquake judgment time, and if those observation points are not considered to be adjacent to any of the observation points that have already observed shaking, wait for observation by a fourth observation point;
When shaking is observed at the fourth observation point within the same earthquake judgment time, if the fourth observation point is deployed at a low density and cannot be considered to be adjacent to an observation point which has already observed shaking, an earthquake monitoring device determines the farthest observation point based on the positions of the four observation points, and judges that the shaking observed at the farthest observation point is not caused by an earthquake. The computer
In a high-density range where the number of observation points deployed in a predetermined range is equal to or greater than a predetermined number, when shaking is observed at two or more observation points deployed in the high-density range within a same earthquake determination time that can be considered to be the occurrence of the same earthquake, for each of the two or more observation points that observed shaking, it is determined whether there are two or more observation points that can be considered to be adjacent that observed shaking;
Calculate the epicenter and/or earthquake magnitude using the observation results of each of the observation points considered to be adjacent to each other;
Furthermore, in the determination, if after the first observation point observes shaking, the second observation point cannot observe shaking even after the same earthquake determination time has elapsed, the shaking observed at the first observation point is determined to be not caused by an earthquake,
When the first observation point is deployed in a low-density range where the number of the observation points deployed in a predetermined range is less than the predetermined number, the shaking observed by the first observation point is determined to be shaking caused by an earthquake.
Earthquake monitoring methods. On the computer,
In a high-density range where the number of observation points deployed in a predetermined range is equal to or greater than a predetermined number, when shaking is observed at two or more of the observation points deployed in the high-density range within a same earthquake determination time during which the same earthquake can be deemed to have occurred, a determination is made for each of the two or more observation points that observed shaking, as to whether or not there are two or more observation points that can be deemed to be adjacent to each other that observed shaking;
Calculating the epicenter and/or earthquake magnitude using the observation results of each of the observation points considered to be adjacent to each other;
Furthermore, in the determination, if after a first observation point observes shaking, a second observation point does not observe shaking even after the same earthquake determination time has elapsed, the shaking observed at the first observation point is determined to be not caused by an earthquake,
When the first observation point is deployed in a low-density range in which the number of the observation points deployed in a predetermined range is less than the predetermined number, the shaking observed by the first observation point is determined to be shaking caused by an earthquake.
A program containing instructions.

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