JPS60249080A - Method and device for geological analysis by aerial measurement of gamma rays - Google Patents

Abstract

PURPOSE:To detect automatically a dislocation, crack and hot water vein by detecting the gamma rays of different energy bands from the object land by the gamma ray detecting members mounted on an aerial flying body and measuring at the same time the change in the altitude from the ground surface and the temp. of the ground surface as well as the change of the dose ratio with each energy band. CONSTITUTION:The outputs from the environmental gamma ray detector 10, gamma ray detector 12 for <40>K system, gamma ray detector 14 for <238>U system and gamma ray detector 16 for <232>Th mounted on the flying body are respectively converted to logarithm by logarithm circuits 18, 20, 22, 24. The outputs from the circuits 18, 20, 24 are fed to subtractor circuits 26, 28, 30, by which the dose ratios K/U, K/Th and U/Th of the respective gamma rays are determined and are fed together with the output from the circuit 18 and the outputs from a radio altimeter 32, a pressure altimeter 34, a speedometer 36 and a radiation thermometer 38 to an arithmetic circuit 40. The circuit 40 determines the presence of the dislocation, crack and hot water vein from the input data, actuates an alarm member 42 if necessary and records the input data into a recorder 44.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a geological analysis method and apparatus using gamma ray aerial measurement.

[Prior art] Methods such as radioactivity exploration, elastic wave exploration, and electrical exploration have traditionally been used to explore faults, cracks, and warm water veins, but these methods not only require special techniques and skills, but also require Either the system had not been established or the method was not sufficiently practical in terms of exploration and analysis period and economic efficiency.

[Problems to be solved by the invention] The present invention provides an exploration method and device that can automatically search for locations where faults, cracks, and warm water veins may exist without requiring special knowledge or technology. The purpose is to make suggestions.

Means for Solving Problem E] The geological analysis method and device according to the present invention detect environmental gamma rays, 0-series gamma rays and)) PU-based gun cotton wire 232Th-series gamma rays while moving a gamma ray detector in the air. From the ground surface altitude, ground surface temperature, ground speed, and time measured simultaneously, the topographic slope conversion lines, valley bottoms, and ridges on the ground surface are automatically extracted, and the environment at that location is calculated. Cant number of gamma rays, radon daughter element"'
Cant number ratio between B i and potassium 90 xlQBr /
″″K, Tron Musume Element 2o? The Kant number ratio of T y and force IJ + cum'' is T 12 / '.

Cant number ratio of K and thoron daughter element and radon daughter element "'T
9. / 3i and the rate of change in ground surface temperature, etc., to determine the presence and scale of geothermal heat in faults, cracks, and the presence or absence of surface water, and to explore faults, cracks, underground water veins, and hot spring veins. Features.

[Principle of the Invention] The present inventor believes that if there is a possibility of underground water supply in a place where there is a fault or crack, there is a possibility that a groundwater vein exists, and in addition, a hot spring vein exists in a place where there is geothermal heat. The existence of faults and cracks, the existence of surface water and underground water, and the possibility of the presence or absence of geothermal heat can be detected from airborne gamma rays, ground surface heating, ground surface altitude, ground speed, flight time, etc. discovered.

Radioactive elements uranium-222U and thorium-2 found in rocks
317 h, Potassium Ia K is in the process of emitting radiation and decaying into a stable element, changing from uranium to radon.
Gaseous elements such as Rn, t-IJum and 2aoTn are passed through, but the higher the ground temperature is during this period, the higher the pressure of radon gas and thoron gas, causing gas movement along the cracks. However, the half-life of radon is 3,825 days, while that of thoron is 54.5 seconds, and there is a large difference between them, so the ratio between the elements changes due to movement. Therefore, if there is a crack in the ground, the separation of radioactive elements progresses, and the gamma ray ratio of the U series and the gamma ray ratio of the 21" Th series relative to the gamma ray dose of the ' series increases. The ratio of the gamma radiation dose of the H series to the gamma dose of the 2ゝ2U series is relatively low in the area. Faults, cracks, etc. are generally exposed on the ground at topographical slope conversion lines, valley bottoms, and ridgelines, but in these areas, the gamma dose ratio of the 2' series/U series and '
The presence of faults, cracks, and underground water veins is predicted when the gamma dose ratio of the series/Th series is relatively low, and when the gamma dose ratio of the U series/Th series is relatively high. Predicting the existence of geothermal high temperature areas,
When the gamma ray dose ratio of the ' series/U series is relatively low and the gamma dose ratio of the 132U series/232Th series is relatively high, the presence of hot spring veins is predicted. The present invention is characterized by searching for faults, fissures, and warm water veins from topographic slope conversion lines, valley bottoms, or ridgelines where the dose ratios of different gamma rays in one energy band exhibit relatively abnormal changes.

Known faults, cracks, and
Gamma rays in the energy range of each nuclide above the warm water vein,
As a result of measuring flight altitude, altitude above ground, surface temperature, ground speed, flight time, etc., the time difference height of ground surface altitude, which is obtained by subtracting altitude above ground from flight altitude, was calculated by dividing the difference between ground speed and flight time. Using the rate of change in the topographical slope (tanθ) and the rate of temperature change obtained by dividing the time difference value of the ground surface temperature by the product of ground speed and flight time, possible locations of faults and cracks from the appearance and surface water can be determined.・It has been discovered that it is possible to know the possibility of the presence or absence of underground water. In other words, faults and cracks are likely to exist in places where the rate of change in topographical slope is large, and in places where surface water or underground water exists, the ground surface temperature differs by several degrees compared to the surrounding area. The present invention provides a means for determining whether or not the possible existence of faults/cracks extracted from this topographical data is also supported by internal factors. is 1lJi by comparing the cant number ratio Bi/of the radon daughter element of gamma rays with potassium.
This ratio is usually more than double near the layer, the surface temperature changes by several degrees or more from the surrounding area due to the presence of surface water and underground water, and in geothermal areas, the cant of thoron daughter elements and radon daughter elements Number ratio "'t" 1! Judgment is made based on the criterion that 5'B i has decreased to 80% or less of the normal zone.

DESCRIPTION OF THE EMBODIMENTS FIG. 1 shows a schematic block diagram of equipment mounted on a helicopter to carry out the invention. 10 is a detector consisting of a scintillator and a pulse height analyzer for environmental gamma rays, 12 is a detector for series gamma rays, and 14 is 233
16 is a gamma ray detector for the 2uT 6 series. The output of each detector 10-16 is logarithmized by a logarithmization circuit 18-24, respectively. The output of the logarithmization circuit 20 and the output of the logarithmization circuit 22 are
The subtraction circuit 26 performs subtraction.

The output of the subtraction circuit 26 indicates the ratio of the K-series gamma ray dose to the J-series gamma ray dose.Similarly, the subtraction circuit 28
The difference between the output of the logarithmization circuit 20 and the output of the logarithmization circuit 24 is calculated, and the subtraction circuit 30 calculates the difference between the output of the logarithmization circuit 22 and the output of the logarithmization circuit 24. In addition, a radio altimeter 32, a barometric altimeter 34, a speedometer 36, and a radiation thermometer 3
Load 8. Data from these are utilized to calculate the rate of change of terrain slope and rate of temperature change described above.

Detector 10 for environmental gamma rays is used to monitor object and background effects.

The output of the logarithmization circuit 18, the output of the subtraction circuit 26, 28, 30 and the output of the device 32, 34, 36, 38 are fed to an arithmetic circuit 40. The arithmetic circuit 40 calculates whether or not the corresponding conditions are satisfied for each of the above-mentioned judgment elements, outputs an output when necessary, and operates the R-reporting member 42.

The alarm member 42 notifies the surveyor of the discovery of a hot spring vein, for example, by means of light or sound. In addition, these devices 18, 26 to 3
The output of 8 is recorded in a data recorder 44 for precise analysis on the ground.

In order to easily confirm the gamma ray survey after the corresponding area d, it is preferable to record visible light images and thermal infrared ray images of the gamma ray exploration area on a video tape recorder in synchronization with this jJ gamma ray measurement.

Although not shown in FIG. 1, this analysis device includes a clock circuit that operates the gamma ray detectors 10 to 16, the arithmetic circuit 40, etc. in synchronization, and determines the data sampling time and period. It is provided.

Figure 2 is a graph of measurement data regarding hot spring veins. The horizontal axis indicates flight time or flight distance. The upper part of the graph shows flight altitude (1, ground altitude △h and ground surface altitude 112. △11) on the normal vertical axis scale, and the lower part shows environmental gamma rays (chi), K series gamma rays (ch2),
U-series gamma rays (ch3) and x! 2Th series gamma rays (ch4) are shown on a logarithmic scale on the vertical axis. The part indicated by the upward arrow is the valley part, and is the 232U series) 3
The significantly large ratio of gamma rays in the 2-rh series suggests the existence of hot spring veins.

Specifically, a small and inexpensive personal computer can be used as the arithmetic circuit 40, and therefore, the maximum value, minimum value, average value, etc. of each sampling value of data from each device can be recorded as appropriate. By incorporating programming and software into the system, changes in gamma ray doses in each energy band can be easily discovered. That is, the arithmetic circuit 40 of this embodiment is configured such that the topographical slope (tan θ) changes by more than twice and the cant number ratio of radon daughter element and potassium “'Bi
/"When K changes by more than twice, it indicates that there is a high possibility of the existence of faults and fissures.The topographical slope becomes more than twice as much, the sign of the slope changes, and the radon daughter element and the force increase. If the number ratio 2''Bi/'''K changes by more than 2i8 and the ground surface wetness changes by more than a few degrees Celsius, the Kant number ratio of the thoron daughter element and the radon daughter element changes. 'T 11.
/ ``'B When + decreases, it indicates that there is a high possibility of the existence of hot spring veins, and on the contrary, Tel 21''B
When H increases, it indicates that there is a high possibility that a groundwater vein exists. In these significant situations, the arithmetic circuit 40 outputs an alarm signal to the alarm member 42. When using an XY plotter or CRT, a predetermined alarm signal is output on the plotter paper or CRT.

When collecting data, the flight altitude, ground altitude, and ground speed are usually input into the data recorder every second, so the relationship between the flight distance and the ground surface altitude can be determined, and as a result, the terrain cross section is input into the data recorder. I yelled that it was done to me.

At the same time, since the ground surface temperature is also input to the data recorder by the radiation thermometer 38, it is possible to grasp how the ground surface temperature changes in response to changes in land use. In places with a lot of moisture on the earth's surface, and in valley bottoms with surface water and underground water, the temperature differs by several degrees from the surrounding area (higher in winter and lower in summer)
Therefore, if this data is linked with topographical cross-section data, it will be possible to detect the presence of water that serves as a storage source for groundwater and hot spring water at intervals of 25 m, assuming a flight speed of 90 km/h. .

In addition, in the present invention, the cant number of airborne gamma rays corresponding to each nuclide is normally measured for 5 seconds, and when flying at 90kn+ per hour, airborne gamma rays are measured at intervals of 125m above the ground surface. Since the flight altitude is normally 100m above the ground, 90% of the radiation emitted from a 500W diameter area on the ground is measured.

In addition, with this exploration device, the data collection time can be shortened to 0.5 seconds, and by taking the cumulative sum of 5 seconds to 0.5 seconds, the ground resolution can be reduced to 12.5 seconds when flying at 90 km/hour.
It can be raised up to 5m.

In order to automatically analyze faults, cracks, and warm water veins in a plane according to the present invention, the topographical information, ground surface temperature information, and gamma ray information recorded in the data recorder 44 are processed on the ground, and the faults are displayed on a plotter or CRT.・It is sufficient to display two-dimensionally the locations where cracks and warm water veins are likely to exist. This program is basically the same as the operating program of the arithmetic circuit 40, except that it also processes exploration position data.

[Effects of the Invention] According to the present invention, by processing airborne gamma rays and various types of flight information, positions where there is a high possibility of the existence of faults, cracks, and water veins can be immediately identified, or using a plotter or CRT. It can be discovered two-dimensionally, and no special knowledge or skill is required to make that determination.

[Brief explanation of drawings]

FIG. 1 is a schematic block diagram of an apparatus for implementing the present invention, and FIG. 2 is a graph showing an example of measurement data. 10.12, 14.16... Gamma ray detector 18.2
0,22.24...logarithmization circuit 26,28.30・
...Subtraction circuit 32...Radio altimeter 34...Barometric altimeter 36...Speed meter 38...Copper thermometer 40.
...Arithmetic circuit 42...Alarm member 44...Data...
recorder

Claims (7)

[Claims] (1) Using an IC gamma ray detection component mounted on an aerial vehicle, the dose of multiple gamma rays in different energy bands from the analysis target area is measured, and at the same time, the ground surface altitude and ground surface temperature are measured, and the ground surface altitude is measured. A geological analysis method by aerial measurement of gamma rays, which is characterized by exploring the geology from changes in ground surface temperature, changes in ground surface temperature, and changes in the dose ratio for each energy band of the measured gamma rays. (2) The method according to claim 1, wherein the gamma rays include at least ' series gamma rays, '32U series gamma rays, and Th series gamma rays. (3) When the topographic slope changes by more than 2 times and the cant number ratio Bi/K of radon daughter element and potassium changes by more than 2 times, it indicates the existence of faults/cracks, and the topographic slope changes by more than 2 times. , the sign of the slope changes, the cant number ratio 2'''B+/''K of radon daughter element and potassium changes by more than twice, the ground surface temperature changes by more than several degrees Celsius, and the cant number ratio of radon daughter element and potassium daughter element changes by more than a few degrees Celsius. 1 - The topographical slope changes by more than 2 times, the sign of the slope changes, and the cant number ratio of radon daughter element and potassium is 1″Bi/
``0K changes by more than twice, the ground surface temperature changes by more than a few degrees Celsius, and the Kant number ratio of thoron daughter element and radon daughter element'''T 1
! 2. A method according to claim 2, characterized in that when B r increases, it indicates the presence of a groundwater vein. (4) The method according to any one of claims (1) to (3), characterized in that the ground surface altitude is obtained from the measured values of flight altitude and ground altitude. (5) a flight vehicle; at least three gamma ray detectors with different detection T energy bands loaded on the flight vehicle; and an aircraft that is f1-controlled by the flight vehicle and measures the ground surface altitude of the measurement area; A member that is loaded on the aircraft and measures the ground surface temperature in the measurement area; a ratio calculation member that obtains a signal indicating the ratio between each output of the gamma ray detector; and the output of the ratio calculation member and the ground surface altitude. It consists of an arithmetic circuit that generates a predetermined alarm signal based on data and ground surface temperature data when these indicate a predetermined change, and an alarm member that generates a predetermined alarm in response to the output of the arithmetic circuit. A geological analysis device that uses gamma ray aerial measurements. (6) The apparatus according to claim (5), wherein the gamma rays include at least `` series gamma rays, '33U series gamma rays, and 2JLT 1. series gamma rays. (7) The arithmetic circuit indicates the existence of a fault/crack when the topographic slope changes by more than twice and the Cant number ratio z+QBi,/KoK of 'radon daughter element and potassium l\ changes by more than twice. , terrain slope is 2
The sign of the slope changes, and the number ratio Al5I B+/K of radon daughter element and potassium cum is 248.
The ground surface temperature changed by several degrees Celsius or more, and the ratio of the thoron daughter element to the radon daughter element increased.
When i decreases, it indicates the existence of hot spring veins, the topographical slope changes by more than twice, the sign of the slope changes, the cant number ratio alpB+i''K of radon daughter element and potassium changes by more than twice, When the surface temperature changes by several degrees Celsius or more, the Cant number ratio of the thoron daughter element and the radon daughter element T 9. / Feng B
Device according to claim 6, characterized in that when i increases, it indicates the presence of a groundwater vein λof. (2) The ground surface height measuring member obtains the ground surface height from the measured values of the flight altitude and the ground altitude, according to any one of claims (5) to (7). equipment.