JP2010091480A - Long-period ground motion detector and long-period ground motion detecting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect the occurrence of long-period ground motions prior to the propagation of long-period ground motions through the use of an emergency earthquake early warning. <P>SOLUTION: A long-period ground motion detector 30 has previously stored conditions on magnitudes; earthquake focal depths; and epicentral distances determined on the basis of results of statistical processing of magnitudes of reported earthquakes in which a plurality of long-period ground motions have occurred; earthquake focal depths; and epicentral distances and at which the long-period ground motions are estimated to have occurred. The long-period ground motion detector 30 outputs a long-period ground motion detection signal G indicating the detection of the occurrence of long-period ground motions in the case that magnitude; earthquake focal depth; and epicentral distance are extracted from an emergency earthquake early warning S and that it is determined that they satisfy conditions on magnitude; earthquake focal depth; and epicentral distance. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a long-period ground motion detector and a long-period ground motion detection method.

  There are two types of seismic waves: P waves and S waves. The S wave is a roll wave (main motion) that causes earthquake damage. The P wave propagates faster than the S wave, but the magnitude of the vibration is a pitch wave (initial movement) smaller than the S wave. As a method for detecting seismic waves, for example, in Patent Document 1, not only the magnitude of the epicenter, the location of the epicenter (latitude, longitude), the seismic depth, and the arrival time and magnitude of the seismic motion obtained from the earthquake early warning, Using a neural network whose input parameters are the dynamic period such as the predominate period of the ground at the target point, the natural period of the building, and the attenuation rank if inside the building, the main earthquake motion (S wave) arrives Prior to this, a technique for estimating the level of shaking or damage at a target point is disclosed.

  By the way, in recent years, long-period ground motions (surface waves having a period of several seconds to several tens of seconds) that come after P waves and S waves have begun to attract attention. Damage caused by long-period ground motion is in buildings with long-period natural frequencies (especially high-rise buildings). It is said that the area where long-period ground motion occurs is an area with a deep basin structure with soft ground several kilometers from the ground surface to the rock. In particular, in the deep underground of the Kanto Plain, there are a number of dents called “Half Graben”, which are thought to potentially amplify long-period ground motion locally. Yes. However, Patent Document 1 does not disclose that long-period ground motion is detected.

For example, the Niigata Prefecture Chuetsu Earthquake on October 23, 2004 not only damaged the area near the epicenter, but also a skyscraper in Tokyo, which is more than 300 kilometers away from the epicenter due to long-period ground motion. An accident occurred that damaged part of the elevator. Therefore, long-period seismic motion detectors such as a pendulum sensor (for example, see Patent Document 2 shown below) and a long object shaking prediction sensor (for example, see Patent Document 3 shown below) have been developed mainly by elevator manufacturers. Has been. The long-period ground motion detector has a mechanism for detecting after the long-period ground motion has arrived.
JP 2006-170739 A JP 2007-153520 A JP 2008-114944 A

  However, the above long-period ground motion detector was installed in the elevator of a high-rise building, and when the occurrence of long-period ground motion was detected by the above long-period ground motion detector, the elevator was controlled to stop at the nearest floor. However, there is a risk that the stop to the nearest floor will not be in time. For example, a skyscraper has an elevator with a stop floor (for example, an elevator where the stop floor is a high floor with a ground floor and an observation room). There is a risk of significant vibration from periodic ground motion.

  This invention is made | formed in view of said problem, The objective is to detect generation | occurrence | production of a long-period ground motion before long-period ground motion is transmitted using an emergency earthquake bulletin.

  The present invention is a long-period ground motion detector that detects long-period ground motion, and is determined based on the results of statistical processing of the magnitude, epicenter depth, and epicenter distance of a plurality of reported long-period ground motion earthquakes. In addition, a storage unit that stores the conditions for the magnitude, epicenter depth, and epicenter distance that the long-period ground motion is estimated to have occurred, a receiving unit that receives an emergency earthquake warning, and the magnitude and source An extraction unit for extracting depth and epicenter distance; a magnitude determination unit for determining whether the magnitude extracted from the extraction unit satisfies a condition for the magnitude; and a source depth extracted from the extraction unit. , An epicenter depth determination unit that determines whether or not a condition about the epicenter depth stored in the storage unit is satisfied, and an earthquake extracted from the extraction unit It is determined that the distance satisfies the condition for the magnitude by the epicenter distance determination unit for determining whether or not the condition for the epicenter distance stored in the storage unit is satisfied, and the magnitude determination unit, and Generation of long-period ground motion when it is determined by the epicenter depth determination unit that the condition for the epicenter depth is satisfied and the epicenter distance determination unit determines that the condition for the epicenter distance is satisfied And a long-period ground motion detection unit that outputs a long-period ground motion detection signal indicating that the motion is detected.

  Further, in the long-period ground motion detector described above, the magnitude condition is that the magnitude is 5.5 or more, and the condition of the epicenter depth is that the epicenter depth is within a range from 5 km to 25 km. The epicenter distance may be set such that the epicenter distance is within a range from 100 km to 1000 km.

Another aspect of the present invention is a long-period ground motion detection method for detecting long-period ground motion, which is based on the results of statistical processing of magnitude, epicenter depth, and epicenter distance in a plurality of reported long-period ground motion earthquakes. Storing the determined conditions regarding the magnitude, epicenter depth, and epicenter distance that are estimated to have caused the long-period ground motion, and receiving an earthquake early warning;
Extracting magnitude, epicenter depth, epicenter distance from the earthquake early warning;
Magnitude extracted from the earthquake early warning, epicenter depth, epicenter distance, conditions for the magnitude, conditions for the epicenter depth, determining whether or not the conditions for the epicenter distance are satisfied,
If it is determined that the magnitude, epicenter depth, and epicenter distance extracted from the earthquake early warning satisfy the conditions for the magnitude, the seismic depth, and the epicenter distance, a long period Outputting a long-period ground motion detection signal indicating that the occurrence of ground motion has been detected;
A long-period ground motion detection method characterized by comprising:

  According to the present invention, it is possible to detect the occurrence of a long-period ground motion with considerable accuracy before the long-period ground motion is transmitted using an emergency earthquake warning.

＝＝＝ Boundary conditions where long-period ground motion is estimated to occur ＝＝＝
Fig. 1 is a summary of recent news reports of major earthquakes. Among the total of 13 earthquakes shown in Figure 1, there were 5 earthquakes, including the Iwate-Miyagi inland earthquake, the Niigata-Jochuetsu-oki earthquake, the Noto peninsula-oki earthquake, the Niigata-Chuetsu regional earthquake, and the Miyagi-ken Hokubu earthquake. It is an earthquake with long-period ground motion in and around the Tokyo metropolitan area.

  FIG. 2 is a two-dimensional graph in which the relationship between the epicenter depth and magnitude is plotted for the 13 earthquakes shown in FIG. In FIG. 2, among the total of 13 earthquakes shown in FIG. 1, the ● mark indicates an earthquake in which long-period ground motion occurred in the Tokyo metropolitan area and its vicinity, and the △ mark is a long period in the Tokyo metropolitan area and its vicinity. It shows an earthquake where no earthquake motion occurred. In Fig. 2, the characteristics of a total of five earthquakes in which long-period ground motion occurred in and around the Tokyo metropolitan area is a magnitude of 5.5 or more and the range of the epicenter depth from 5 km to 25 km. Yes.

  FIG. 3 is a two-dimensional graph in which the relationship between epicenter distance and epicenter depth is plotted for a total of 13 earthquakes shown in FIG. In FIG. 3, among the total of 13 earthquakes shown in FIG. 1, ● indicates an earthquake in which a long-period ground motion occurred in and around the Tokyo metropolitan area, and △ indicates a long-period in the metropolitan area and its vicinity. It shows an earthquake where no earthquake motion occurred. According to FIG. 3, the attributes of a total of five earthquakes in which the long-period ground motion occurred in and around the Tokyo metropolitan area are in the range from epicenter distance 100 km to 1000 km and in the range from epicenter depth 5 km to 25 km. It represents something.

  To summarize the above results, it is estimated that the long-period ground motion was generated, which was determined based on the results of statistical processing of magnitude, epicenter depth, and epicenter distance in the reported earthquakes that generated multiple long-period ground motions. You can set conditions for magnitude, epicenter depth, and epicenter distance. Specifically, the condition for magnitude is magnitude 5.5 or more, the condition for epicenter depth is in the range from epicenter depth 5 km to 25 km, and the condition for epicenter distance is in the range from epicenter distance 100 km to 1000 km. Can be inside.

=== Configuration of long-period ground motion detection system ===
FIG. 4 is a diagram showing a configuration of a long-period ground motion detection system including a long-period ground motion detector 30 according to an embodiment of the present invention. The long-period ground motion detection system compares the magnitude, epicenter depth, and epicenter distance included in the JMA emergency earthquake bulletin with the above-mentioned conditions for magnitude, epicenter depth, and epicenter distance. It is a system that detects occurrence.

  An EPOS (Earthquake Phenomena Observation System) 20 is a comprehensive monitoring system such as seismic activity of the Japan Meteorological Agency, and is an information processing device including a CPU, a memory, a display device, and the like. The EPOS 20 estimates the magnitude M (the magnitude of the earthquake), the epicenter distance X, the epicenter distance Y, the epicenter depth D, etc. by analyzing the information observed by the seismometer 10 installed near the epicenter. FIG. 5 shows the relationship between the epicenter distance X, the epicenter distance Y, and the epicenter depth D. The epicenter distance X is the distance from the point (seismic center) where the earthquake occurred to the observation point A on the ground surface. The epicenter distance Y is the distance from the point (the epicenter) directly above the ground surface of the point where the earthquake occurred (the epicenter) to the observation point A. The epicenter depth D is a range from the minimum Dmin to the maximum Dmax, and the epicenter distance Y is a range from the minimum Ymin to the maximum Ymax. The EPOS 20 delivers an emergency earthquake bulletin having such estimated information.

  The long-period ground motion detector 30 includes a storage unit 31, a reception unit 32, an extraction unit 33, a magnitude determination unit 34, an epicenter depth determination unit 35, an epicenter distance determination unit 36, and a long-period ground motion detection unit 37. A long-period ground motion detection signal G is output based on the earthquake early warning S received from the EPOS 20.

  The storage unit 31 includes a condition for the magnitude (magnitude 5.5 or more) estimated that long-period ground motion has occurred, a condition for the epicenter depth (seismic depth from 5 km to 25 km), and a condition for the epicenter distance ( Epicenter distance 100 km to 1000 km) is stored. The storage unit 31 is realized by, for example, a register or a ROM.

  The receiving unit 32 receives the earthquake early warning S from the EPOS 20. The receiving unit 32 is realized by an antenna or the like, for example. The extraction unit 33 extracts the magnitude M, epicenter distance Y, and epicenter depth D included in the emergency earthquake bulletin S received by the reception unit 32, respectively.

  The magnitude determination unit 34 refers to the condition about the magnitude (magnitude 5.5 or more) stored in the storage unit 31 and determines whether the magnitude M extracted by the extraction unit 33 satisfies the condition about the magnitude. Determine. The magnitude determination unit 34 outputs a determination flag F1 to the long-period ground motion detection unit 37 when it is determined that the extracted magnitude M satisfies the condition for the magnitude.

  The epicenter depth determination unit 35 refers to the condition of the epicenter depth stored in the storage unit 31 (range from the epicenter depth of 5 km to 25 km), and the epicenter depth D extracted by the extraction unit 33 is Determine whether the conditions for the depth of the epicenter are satisfied. And the epicenter depth determination part 35 outputs the determination flag F2 to the long-period ground motion detection part 37, when the extracted epicenter depth D satisfies the conditions regarding the epicenter depth.

  The epicenter distance determination unit 36 refers to the condition about the epicenter distance stored in the storage unit 31 (the range from the epicenter distance 100 km to 1000 km), and the epicenter distance Y extracted by the extraction unit 33 is related to the epicenter distance. It is determined whether or not the above condition is satisfied. And the epicenter distance determination part 36 outputs the determination flag F3 to the long period ground motion detection part 37, when the extracted epicenter distance Y satisfies the conditions about the epicenter distance estimated that the long period ground motion occurred. To do.

  The long-period ground motion detection unit 37 receives the determination flag F1 from the magnitude determination unit 34, the determination flag F2 from the epicenter depth determination unit 35, and the determination flag F3 from the epicenter distance determination unit 36 Then, a long-period ground motion detection signal G indicating that the occurrence of long-period ground motion has been detected is output from the earthquake early warning.

  Fig. 6 summarizes the contents from the first report to the final report as emergency earthquake bulletins in the case of the Niigata-Jochuetsu-oki earthquake. As shown in FIG. 7, the long-period ground motion was transmitted to the Kanto region (10:14:25) about 56 seconds after the first report of the earthquake early warning. Assuming that the conditions for the magnitude, epicenter depth, and epicenter distance are set in the long-period seismic motion detector 30, the first emergency earthquake bulletin (10: 13: 29.3 sec, magnitude 6.2, epicenter depth) Long-period ground motion can be detected from 10 km). Thereby, for example, before the long-period ground motion is transmitted to the Kanto region, the operation of the elevator can be stopped using the long-period ground motion detection signal G output from the long-period ground motion detector 30.

  Although the best mode for carrying out the present invention has been described above, the above embodiment is intended to facilitate understanding of the present invention and is not intended to limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and equivalents thereof are also included in the present invention.

  For example, the conditions regarding the magnitude, the epicenter depth, and the epicenter distance are stored in the storage unit 31, and the storage unit 31 is provided in the magnitude determination unit 34, the epicenter depth determination unit 35, and the epicenter distance determination unit 36. It may be. In this case, each determination unit 34, 35, 36 may store the conditions regarding the magnitude, the epicenter depth, and the epicenter distance in a register or a memory, or may be stored as an algorithm of each determination unit. You may do it.

  In addition to applying the long-period ground motion detection signal G detected by the long-period ground motion detector 30 to the control operation of the elevator as described above (the elevator is stopped at the nearest floor by the long-period ground motion detection signal G), For example, warnings to cranes and their operation control at construction sites and construction sites, warnings to workers at high places (such as window wiping) at construction sites and high-rise buildings, operation control of work floors, warnings to game facilities at game halls, It can also be applied to such operation control.

It is the figure which investigated and summarized the report of the main earthquake that occurred in recent years. It is the figure which showed the two-dimensional graph which plotted the relationship between the epicenter depth and magnitude about the total of 13 earthquakes shown in FIG. It is the figure which showed the two-dimensional graph which plotted the relationship between epicenter distance and epicenter depth about the total of 13 earthquakes shown in FIG. It is the figure which showed the structure of the long period ground motion detection system including the long period ground motion detector. It is the figure which showed the relationship of the three of the epicenter distance, epicenter distance, and epicenter depth. In the case of the Niigata-Jochuetsu-oki earthquake, the contents from the first report to the final report are compiled as emergency earthquake bulletins. In the case of the Niigata-Jochuetsu-oki earthquake shown in FIG. 6, it is the figure which showed that generation | occurrence | production of a long-period ground motion can be detected before long-period ground motion is transmitted to the Kanto district by the 1st report of an earthquake early warning.

Explanation of symbols

10 Seismographs 20 EPOS (Earthquake Phenomena Observation System)
30 Long-period seismic motion detector 31 Storage unit 32 Receiving unit 33 Extraction unit 34 Magnitude determination unit 35 Epicenter depth determination unit 36 Epicenter distance determination unit 37 Long-period earthquake motion detection unit

Claims (3)

A long-period ground motion detector that detects long-period ground motion,
Magnitude, epicenter depth, and estimated depth of the long-period ground motion determined based on the statistical processing of the magnitude, epicenter depth, and epicenter distance of the earthquakes in which multiple long-period ground motions were reported. A storage unit that stores conditions for epicenter distance;
A receiver for receiving the earthquake early warning;
An extraction unit for extracting magnitude, epicenter depth, epicenter distance from the emergency earthquake bulletin;
A magnitude determination unit that determines whether the magnitude extracted from the extraction unit satisfies a condition for the magnitude; and
An epicenter depth determination unit that determines whether the epicenter depth extracted from the extraction unit satisfies a condition for the epicenter depth stored in the storage unit;
An epicenter distance determining unit that determines whether or not the epicenter distance extracted from the extracting unit satisfies a condition for the epicenter distance stored in the storage unit;
The magnitude determining unit determines that the condition for the magnitude is satisfied, the seismic source depth determining unit determines that the condition for the epicenter depth is satisfied, and the epicenter distance determining unit determines the epicenter A long-period ground motion detection unit that outputs a long-period ground motion detection signal indicating that the occurrence of a long-period ground motion is detected when it is determined that the condition for the distance is satisfied;
A long-period ground motion detector characterized by comprising: The long-period ground motion detector according to claim 1,
The condition for the magnitude is that the magnitude is 5.5 or more,
The condition of the epicenter depth is that the epicenter depth is within a range of 5 km to 25 km,
The condition for the epicenter distance is that the epicenter distance is within a range from 100 km to 1000 km,
A long-period seismic motion detector. A long-period ground motion detection method for detecting long-period ground motion,
Magnitude, epicenter depth, and estimated depth of the long-period ground motion determined based on the statistical processing of the magnitude, epicenter depth, and epicenter distance of the earthquakes in which multiple long-period ground motions were reported. Memorizing conditions for epicenter distance;
Receiving an earthquake early warning;
Extracting magnitude, epicenter depth, epicenter distance from the earthquake early warning;
Magnitude extracted from the earthquake early warning, epicenter depth, epicenter distance, conditions for the magnitude, conditions for the epicenter depth, determining whether or not the conditions for the epicenter distance are satisfied,
If it is determined that the magnitude, epicenter depth, and epicenter distance extracted from the earthquake early warning satisfy the conditions for the magnitude, the seismic depth, and the epicenter distance, a long period Outputting a long-period ground motion detection signal indicating that the occurrence of ground motion has been detected;
A long-period ground motion detection method characterized by comprising: