JP2813769B2 - Method and apparatus for calculating the magnitude and source area of an earthquake by observing electromagnetic fields - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for observing an electromagnetic field generated in an epicenter area before an earthquake, and determining the magnitude and the epicenter area of the earthquake at least one hour before the occurrence of the earthquake. The present invention relates to a method and an apparatus for calculating an earthquake magnitude and an epicenter area.

[0002]

2. Description of the Related Art At present, there are two types of techniques for observing an electromagnetic field and routinely predicting the epicenter, magnitude, and occurrence time before an earthquake.

(1) Earthquake Forecast by Observing Geoelectric Potential in Greece: A technology developed by the Physical Department of the University of Athens in Greece. It has been done. 100k
There are 16 or more observation points about m apart. Many are located in places where there is little artificial noise, such as in the army training grounds, and natural noise due to rainfall and the like is constantly monitored by humans. Each observation point has four baselines, east / west / north / south, and long / short, and since local noise appears differently on the four baselines,
Geopotentials associated with a global magnetic storm appear simultaneously at many observation points, and are distinguished from those at the precursor of an earthquake. An earthquake occurred within about one month (about 11 days later) from the anomaly of the earth potential of the precursor of the earthquake, and the location error was about 100 k
m, the error of the magnitude is about 0.7, and both the forecast rate and the hit rate are about 0.7.

(2) Earthquake Forecast by Observing Omega Radio Waves in Russia: A technology developed at the Russian Academy of Sciences Geophysical Research Institute, and since 1991, earthquake prediction has been performed by receiving omega radio waves. Omega radio waves of 9 to 13 kHz have a magnitude of 6 or more near the propagation path excluding the transmission / reception point.
30 days before, an abnormality is observed in the phase of the received wave. The forecast error, forecast rate, and hit rate of the place are similar to those of the technique of (1).

[0005]

[Problems to be Solved by the Invention] [Prior Art]
The technique (1) has the disadvantage of requiring long-term experience,
The technology of (2) requires the emission of radio waves,
There is a drawback that operation is difficult. In both of the techniques (1) and (2), the prediction of the date and time and place are vague, and it is very difficult to test the significance of these prediction techniques. In addition to the lack of significance, these forecasts are far from societal demands, so the economic losses from forecasts are very large. For example, if the location error is 100 km in radius, and if a person who lives within the range of the error evacuates for 30 days, which is the maximum value of the date and time error, and economic activity stagnates within this range and period, it is predicted that The resulting economic loss is likely to be more than twice the economic damage if not foreseen. As described above, the conventional forecast technology has problems that it is difficult to use in Japan, that accuracy is far from social demands, and that economic loss due to forecast is large.

The present invention solves the above problems,
The present invention provides a method and an apparatus for calculating an earthquake area with a magnitude of 6 km or more and an earthquake area of about 10 km with an error of about 1 to 3 hours in advance and minimizing economic loss due to forecasting.

[0007]

In the eighteenth century, it was already said that geomagnetism and geocurrent would change before the earthquake. 196
The magnitude 7.2 earthquake in China in March 2006 triggered the possibility of the presence of earthquake precursory radio waves. Since 1976, many examples of observations of earthquake precursory radio waves have been published. Despite the many observations, the reason why earthquake prediction based on electromagnetic field observation has been questioned so far is that electromagnetic fields synchronized with the occurrence of the earthquake were not observed. The reason is that if a precursor electromagnetic field is generated, there is a high possibility that an electromagnetic field of a similar mechanism will be observed at all even during an earthquake, and that it will not be observed at the time of the occurrence. This was because it was considered to indicate that there was no world. Under such conditions, the largest earthquake in the eastern Hokkaido area, 8.1 magnitude, occurred in the history of observation on October 4, 1994. In the 9 kHz band, the largest electric field fluctuation was observed except for artificial noise and proximity lightning.
Following the success of this observation, the waveform, spectrum, etc. of the electric field generated during and before and after the earthquake can now be observed. According to the observations to date, the larger the magnitude and the seismic intensity, the higher the frequency and amplitude of the precursor electromagnetic field pulse (accurately, a wave packet with a time length of about 5 ms), and the frequency and amplitude of the occurrence 1 to 3 hours before the earthquake It became clear that both became maximum (refer FIG. 2-FIG. 4). FIG.
7. The magnitude at 22:23 on October 4, 994.
1 Received at Hasaki-cho, Ibaraki Prefecture during the 1st Hokkaido Offshore Earthquake
It is a frequency distribution figure of the pulse of the electric field of ９9 kHz. The horizontal axis indicates the date of the year and month shown on the left end. The vertical axis is the number of pulses from 0 minute to 1 minute each hour with an amplitude greater than 0.134 mV. FIG. 3 is a frequency distribution diagram of 1 to 9 kHz electric field pulses received in Hasaki Town, Ibaraki Prefecture, at the time of the magnitude 6.2 earthquake off the coast of Ibaraki Prefecture at 3:00 on January 10, 1995. Others are the same as FIG. FIG. 4 is a frequency distribution diagram of 1 to 9 kHz electric field pulses received in Chikura Town, Chiba Prefecture during the earthquake of FIG. Others are the same as FIG. Earthquake prediction system using this phenomenon (see Fig. 1)
As a result of the development and maintenance of the present invention, the present invention has been achieved.

In order to solve the above-mentioned problems of the prior art, the method of calculating the magnitude and source area of an earthquake by observing an electromagnetic field according to the present invention occurs in the source area, which is the place where the earthquake occurs, before the earthquake. In the method of observing the electromagnetic field and calculating the magnitude and source area of the earthquake before the earthquake, observe the electromagnetic field at at least four observation points, identify the pre-earthquake precursor electromagnetic field pulse, and generate it. The area is calculated as the epicenter, and the magnitude, which is the magnitude of the earthquake,
It was calculated from the length, the pulse amplitude, the number of occurrences, and the frequency of occurrence, and the occurrence of the earthquake was known from the change in the frequency of occurrence of the pulse before the occurrence of the earthquake. In addition, the apparatus for calculating the magnitude and source area of an earthquake based on the observation of an electromagnetic field according to the present invention observes the electromagnetic field generated in the source area, which is the place where the earthquake occurred, before the earthquake, and determines the magnitude and source area of the earthquake. An apparatus for calculating before an earthquake, an electromagnetic field observing means for observing an electromagnetic field at at least four observation points, and a seismic precursor electromagnetic field for identifying a pre-earthquake pre-earthquake electromagnetic field pulse observed by each electromagnetic field observing means. Field identification means, source area calculation means for calculating the generation area thereof, and magnitude calculation means for calculating the magnitude, which is the magnitude of the earthquake, from the width and length of the generation area of the pulse, and the amplitude, number of occurrences, and frequency of the pulse And an occurrence detecting means for knowing the occurrence of the earthquake before the occurrence from the change in the frequency of occurrence of the pulse.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a method of calculating an earthquake magnitude and an epicenter according to the present invention by observing an electromagnetic field will be described. First, in the first stage, by observing the electromagnetic field at at least four observation points, for example, when the distance between the observation points is about 10 to 1000 km, the difference between the reception times is 0.1 to 10 ms or less, respectively. If a pulse is observed in the above, the source of the pulse is identified from at least three independent reception time differences. In the second stage, extraneous pulses are eliminated as compared with those of the above-mentioned pulse waveform and spectrum and those of the known pre-seismic electromagnetic field. In addition, the pulse generation source is compared with the data of the lightning generation region on the market to exclude the pulse generation region due to lightning. In the third stage, the region where the pulse that has not been eliminated is identified as the region where the pre-earthquake electromagnetic field is generated is defined as the epicenter region. In the fourth step, the magnitude is calculated from the width and length of the identified area, and the amplitude and number of generated pulses. The fifth step is to know the occurrence of the earthquake before the earthquake based on the change in the frequency of the pulse emitted from the epicenter.

Next, an embodiment of an apparatus for calculating the magnitude and source area of an earthquake by observing an electromagnetic field according to the present invention will be described with reference to FIG. In the present embodiment, when the magnitude and the seismic intensity are both equal to or larger than a predetermined value (for example, 6), the magnitude is set to an error of 1 or less, and the location is set to an error of 10 or less.
The description will be made on the assumption that the distance is calculated about 1 km to about 1 km before.

At least four observation points approximately 100 km apart from each other, a first observation station composed of the first sensor 1a and the first observation device 2a and a first observation station composed of the second sensor 1b and the second observation device 2b shown in FIG. 2 observation stations, 3rd sensor 1c
And a third observation station composed of the third observation device 2c and a fourth observation station
An electromagnetic field is observed at a fourth observation station including the sensor 1d and the fourth observation device 2d. These first to fourth observation stations function as electromagnetic field observation means for observing the electromagnetic field at at least four observation points. As this observation technology,
Existing technology, for example, "Earthquake precursor electric field fluctuation observation method"
A technique related to (Japanese Patent No. 1813589), that is, a deep well casing steel pipe or a dipole antenna and a loop antenna laid on the sea floor are used as sensors for detecting an electromagnetic field. A pulse having an amplitude (: A0) (refer to the following specification example) of an observed value equal to or larger than a given constant value is transmitted to the master station in FIG. 1 and recorded in the first to fourth data recording devices 3a to 3d. , The number of pulses having an amplitude (: A1> A0) equal to or greater than an arbitrary constant value for each observation point and the frequency distribution thereof are output. At different observation points, the reception time difference is equal to or less than a fixed value (for example, 1 ms) and the amplitude is an arbitrary fixed value (: A2> A0).
When there is a pulse received as described above, the first correlator 4a
To calculate the correlation strength (amplitude) and delay time by the third correlator 4c, and obtain the reception time difference with an error of 10 μs or less. 3 × 10 ⁵ to 10 ⁵ km / s as the propagation speed of the electromagnetic wave
If the data processing device 5 observes at two points, the trajectory (hyperbola) of the position where the source may be generated
If three or more observations are made, the location of the potential source, including the imaginary point (imaginary point), is taken. The information is displayed on the map together with the sold lightning information using the display device 6.

An example of a specification for taking in data at each of the above observation points is shown below.

Specification overview (example of specification)

Frequency: 1 to 9 kHz. Amplitude: 10 μv to 100 mV. Sampling frequency: 50 kHz. Time accuracy: 1 μs.

The identification of an earthquake precursor electromagnetic field pulse (precursor pulse) is based on the pulse amplitude and period. The size, shape, and movement of the waveform, spectrum, and generation area are determined by selecting pulses of the same quality as those of the known precursor pulses. That is, the determination is made according to the following conditions (1) to (4).

(1) Pulses other than a certain range of amplitudes (for example, the above specification example) are not regarded as precursor pulses. (2) A pulse having a fixed period is regarded as artificial noise, and is not a precursor pulse. (3) A pulse whose waveform / spectrum is different from those of the known precursor pulse is not regarded as a precursor pulse. (4) Using the above display result, the pulse generation area
Compared with the lightning information, the pulse in the area where the generation area has the same size, shape, and movement as that of static is not a precursor pulse.

The identification of the region where the pulse is generated can be performed by using an existing technique,
For example, the mutual relationship between observed electromagnetic fields at different observation points concerning a lightning location system, a hypocenter determination system of an earthquake, or a tomography method of a long wave / ground current generation region of an earthquake precursor (Patent No. 1813607). This is performed by creating a tomograph of the generation area by correlation.

According to the results of the observation of the electromagnetic field before the earthquake and the results of the rock destruction experiment, the epicenter area coincides with the above-mentioned generation region of the precursor pulse. This can be explained theoretically as follows. In the epicenter area before the earthquake, a sharp decrease in the resistivity of the crust was observed, and even in a rock destruction experiment, a sharp decrease in the resistivity before the collapse was observed. The rapid decrease in specific resistance is synchronized with the generation of microcracks before collapse, and the crack surface becomes a good conductor. If the resistance of the epicenter before the earthquake sharply decreases, the ground current flowing there will change suddenly, and it will be a source of electromagnetic field fluctuations. During an earthquake, rocks in the epicenter are destroyed, so that an electromagnetic field fluctuation, that is, an electromagnetic pulse, occurs in the epicenter before and after the earthquake.

The above-mentioned pulse amplitude (correlation strength), total number,
Based on the empirical rule that the occurrence frequency increases with the magnitude and seismic intensity, the magnitude is estimated, and the magnitude is calculated using the following empirical formula. M = Log (S) +3.9, M = 2 × Log (L) +3.6, where M: magnitude, S: width (km ² ) of the precursor pulse generation area, L: generation of precursor pulse The length of the area (km).

The above equation can be theoretically explained as follows.
If the energy of the earthquake is E and the slip is D, E is S
-It is almost proportional to D. On the other hand, S is approximately proportional to the square of L, and D is approximately proportional to L. By substituting these relations into the following relational expression (definition) of M and E, the above-mentioned relational expressions of M and S and M and L are obtained except for the constant term. 1.5 × M = Log (E) + k, where k: constant

The calculation of the source area and magnitude before the occurrence of the earthquake is performed as follows. In other words, "if an earthquake occurs at the above-mentioned location (a region where a precursor pulse is generated), the magnitude will be the above value". According to observations, in one hour, the above pulse frequency is 30 times or more (if M increases by 1,
Since the energy of the earthquake is about 31.6 times) (see FIGS. 2 to 4), the method described above, for example,
If we start from when M becomes 5, an earthquake with M over 6 will
With an error of 1 or less, it can be calculated one hour or more ago. That is, when the calculated value of M becomes 5, it is calculated that an earthquake with M of 5 to 6 occurs after 1 hour in the region where the precursor pulse is generated, and thereafter, the calculated value of M changes and becomes larger. In each case, M is increased accordingly.

This method can be explained theoretically as follows. In the case of rock destruction, if the horizontal axis indicates displacement and the vertical axis indicates electric conductivity or the frequency of occurrence of microcracks, graphs similar to those in FIGS. This supports the earlier explanation that seismic precursor pulses correspond to rock microfracture. The distribution is almost normal, the transition is almost proportional to time, the microcracks increase from a certain point, and the rock collapses when the frequency of the microcracks becomes almost maximum (usually a little after the maximum value) I do. That is, it can be known before the collapse from the increase in the microcracks. Since an earthquake involves the collapse of rock, the occurrence of an earthquake can be known from the increase in the number of precursor signs before the earthquake for the above reason.

[0023]

As described above, according to the present invention, it is possible to make a quantitative forecast immediately before a large earthquake accompanying a disaster, and it is possible to prevent runaway, explosion, fire, traffic accident, pressure death, etc. of the reactor due to earthquake motion. Earthquake disaster can be reduced. In addition, eruptions are accompanied by earthquakes, and tsunamis are caused by earthquakes.
Forecast just before the tsunami is also possible.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the concept of a system for identifying a pre-earthquake electromagnetic field and its generation region.

FIG. 2 is a pulse frequency distribution diagram showing a first example of a pulse frequency distribution.

FIG. 3 is a pulse frequency distribution diagram showing a second example of the pulse frequency distribution.

FIG. 4 is a pulse frequency distribution diagram showing a third example of the pulse frequency distribution.

[Explanation of symbols]

1: Sensor (electrode, antenna or magnetic sensor) of the observation station at the observation point. 2: Observation device. 3: Data recording device. 4: Correlator. 5: Data processing device. 6: Display device.

Claims (2)

(57) [Claims] 1. A method of observing an electromagnetic field generated in an epicenter area where an earthquake occurs before an earthquake, and calculating the magnitude and the epicenter of the earthquake before the earthquake. Observing the field, identifying the pre-earthquake precursor electromagnetic field pulse, calculating the area where the pulse occurred, and setting it as the epicenter area, the magnitude M, which is the magnitude of the earthquake, is also the size S of the pulse generation area
"M = log (S) +3.9" is properly from the length L Moshiku
Is calculated based on the relational expression of “M = 2 × log (L) +3.6”, and the calculated magnitude M or M + 1 is calculated.
A method of calculating the magnitude and source area of an earthquake by observing an electromagnetic field, wherein the possibility of occurrence of a model earthquake is known at least one hour before. 2. An apparatus for observing an electromagnetic field generated in an epicenter area where an earthquake occurs before an earthquake, and calculating the magnitude and the epicenter of the earthquake before the earthquake. Electromagnetic field observing means for observing the field, seismic precursor electromagnetic field identifying means for identifying a pre-earthquake precursor electromagnetic field pulse observed by each electromagnetic field observing means, and an epicenter area calculating means for calculating an occurrence area thereof; The magnitude M, which is the magnitude of the earthquake, is determined from the width S or length L of the pulse generation area.
“M = log (S) +3.9” or “M = 2 × lo
g (L) +3.6 ”, and a magnitude calculation unit that calculates the magnitude M or the calculated magnitude M
An apparatus for calculating a magnitude and a source area of an earthquake by observing an electromagnetic field, comprising: an occurrence detection means for knowing the possibility of occurrence of an M + 1-scale earthquake at least one hour before.