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Passive Magnetic Resonance Subsurface Exploration Technology (PMRSE) |
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Contents Information gained from PMRSE surveys Database of resonance frequencies and content calibration tests Survey modes: mapping and sounding
Engineering survey, Crimea, 2006
Copper survey, Polar Ural, 2010
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Passive Magnetic Resonance Subsurface Exploration Technology (PMRSE) is an innovative non-invasive method for performing subsurface investigations. The technology, invented and developed in Ukraine in the early 80’s, is based on the discovery of a neurotechnical method of a non-intrusive reception of natural electromagnetic fields of the Earth and extraction of a useful signal from electromagnetic noise using the phenomenon of stochastic resonance.
The fundamental principles applied in the PMRSE technology are: 1. Every subsurface irregularity forms an electromagnetic anomaly emanating its unique frequency of electromagnetic radiation. 2. Such electromagnetic frequencies can be extracted and measured in the field using the phenomenon of stochastic resonance.
The PMRSE measuring system is a biotechnical complex including electronic equipment and an operator who is connected to the equipment by means of special sensors. The principle of work of the PMRSE system consists in achieving the state of stochastic resonance.
In modern science, numerous experiments have demonstrated that in both biological and non-biological systems the use of noise of a certain intensity level can lead to a significant increase in a system sensitivity thus improving the probability of detecting the subthreshold signal of interest. This is stochastic resonance. In view of existing debates and some variations in interpretation of this phenomenon in modern science as well as its acknowledged multidisciplinary meaning it is worth noting that the essence of the phenomenon of stochastic resonance consists in a possibility of detecting/processing a weak subthreshold signal by applying/using noise of an optimum intensity level and here an important role is granted to the possibility of variation of the noise intensity.
In the presented PMRSE system such a state is achieved by superimposing the reference signal of the preset frequency of the substance of interest, which is generated and maintained by the electronic equipment, upon the natural electromagnetic radiation of the Earth received by a directional antenna (noise of the Earth), with the intensity of the noise, which is already summed up with the reference signal, smoothly and continuously incremented to reach the sensitivity threshold of nervous and muscular tissues of the operator or, in other words, to reach the state of stochastic resonance. Thus, the magnetic resonance signals associated with subsurface anomalies and coming in form of the general noise to the antenna and next to the operator are compared against the reference signal generated by the equipment. Then by modifying the noise intensity, the useful signal compared to the reference is extracted from the general noise and recorded based on the threshold effect which is manifested in the adaptive reaction of nervous and muscular tissues of the operator. At the same time the design of the measuring system, which provides for the possibility to adjust the sensory sensitivity threshold of nervous and muscular tissues of the operator, allows the operator to smoothly modify the value of the stimulating action and measure its optimal value in real physical units. The recorded value of the signal at a resonance frequency (value of the stimulating action) is estimated and converted to real concentration values mathematically based on the experimentally obtained relationships between the signal intensity at a preset frequency and the substance content.
Bedding depth of the objects of interest is determined using resonance wavelengths of radio frequency and a special calculation method. In calculations the resonance properties of antennas used and peculiarities of propagation of circular polarized electromagnetic waves, which form electromagnetic noise of the Earth, in the rock mass are taken into account.
The PMRSE investigations performed by different operators demonstrate a steady reproducibility of the results. As it is proved that biological organisms can sense changes in electromagnetic fields, a trained operator can selectively sense and extract needed signals from the general noise of the Earth and register their presence and intensity using the respective instrumentation.
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The PMRSE technology is used to investigate any subsurface irregularities, both substantive and structural, with their unique resonance frequencies of electromagnetic radiation. It can be applied to survey all kinds of minerals (gas, oil, gold, ores of different metals), aquifers, tectonic fractures, landslides, karst, sites of chemical subsurface contamination, etc.
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INFORMATION GAINED FROM PMRSE SURVEYS
PMRSE technology can provide the following information on geological objects: • presence • composition • boundary in plan • bedding depth and thickness • structure and structural attitude • content and its spatial changes
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Magnetite survey, Australia, 2010
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DATABASE OF RESONANCE FREQUENCIES AND CONTENT CALIBRATION TESTS
One of the main principles applied in the PMRSE technology is that any subsurface irregularities form anomalies, which have their unique resonance frequencies of electromagnetic radiation.
When exploring for a specific substance the PMRSE measuring system is tuned to its resonance frequency generated and maintained by the equipment, which serves as a reference signal during field measurements. Next, the general electromagnetic noise of the Earth received by the antenna is compared to the reference signal and by means of variation of the noise intensity a useful signal is extracted from the noise and the strength of the signal at a resonance frequency is recorded. At present, the PMRSE database includes resonance frequencies for more than 80 most widespread chemical elements and compounds.
To determine content of the substance of concern in rocks in natural occurrence the signal intensity is calibrated using artificial models (rock samples with different substance content) or natural objects with known content and density of the substance of interest. By means of such tests an experimental relationship between the signal intensity at a preset frequency and the substance content can be determined. This allows carrying out subsurface exploration for different kinds of minerals, chemical elements and compounds, and present the field results in real concentration values. For 65 out of 80 substances presented in the PMRSE database of resonance frequencies such calibration tests are already performed and experimental relationships between the signal intensity at a preset frequency and the substance content are determined.
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The PMRSE equipment applied for field survey consists of a portable electronic device about 8 kilograms in weight which is fitted with reference generators of electromagnetic waves, processor, built-in memory and GPS, connector for a standard computer port and a battery for 7-8 hours of autonomous work. The measuring complex also includes a small directional electric antenna for receiving signals of circular polarization, neurosensors for connecting operator to the device, a notebook to transfer field acquired data from the device as well as other servicing and measuring devices.
The electronic unit of the measuring complex is quite compact and convenient for work afoot. The electronic equipment of the measuring complex is used to run remote measurements and record signals at a resonance frequency.
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Example of mapping:
Examples of sounding:
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SURVEY MODES: AREAL MAPPING AND DEPTH SOUNDING
A comprehensive PMRSE field survey is achieved by a combination of two survey modes: areal mapping and depth sounding. While mapping allows exploring subsurface objects in plan, soundings allow exploring subsurface objects in a vertical perspective.
The PMRSE mapping is a process of delineating the boundaries of distribution of the substance of interest and is performed by way of intersecting surveyed objects along profiles. The distance between survey profiles depends on details required and accessibility of the territory. The frequency of records on the profile depends on the speed of movement. When moving along profile one operator can make records of one parameter at a time. Usually this is the content of the substance of interest. By performing mapping of the area it is also possible to trace tectonic faults, caverns, contacts of rocks, etc.
When doing the mapping the work productivity depends on exploration details required and a vehicle used. If exploring afoot, in 1 working day one operator can cover the grid of profiles total 6-8 km long taking readings for one parameter. Using a car such measurements can be performed on the grid of profiles total 100-150 km long.
The results of mapping allow plotting areal maps of mineral deposits or plumes of chemical contamination of underground water or soils in form of projections on the daylight surface or in form of slice-maps at a set depth. A PMRSE map of chromite ore deposits at a set depth is presented as an example on the left.
The PMRSE depth sounding, as a standard well log, allows exploring subsurface objects vertically or at an angle but the method does not need well drilling. The step/interval for signal measurements down the "hole" can vary from 10 cm to 1 m depending on details required to the depth of 5000 m.
The resolution and the minimum step of measurements during soundings depend on the resonance wavelength of the objects of concern as well as resonance properties of the antenna. With each step of measurement the substance content is measured in the rock column 10 cm in diameter and from 1-2 cm to a few decimeters in height depending on the resonance frequency of the surveyed substance. During soundings all the measurements are discrete but when the measurements are performed with a resonance wavelength ratio taken into account, the technology can provide a continuous description of the geologic section.
Each selected location is usually surveyed for a number of parameters. To get a complete description of the geologic section the obligatory parameters for measurements are density of rocks in their natural occurrence, content of two or three rock-forming minerals and possibly moisture of rocks – for layering the cross-section, determining the watering of rocks and a possible position of the mineral(s) of concern. Additionally, the measurements of content of the substances of concern are carried out to the whole exploration depth or in a set depth interval. The substances of concern can be any kinds of minerals in exploration projects and chemical compounds of a technogenic origin in environmental projects.
When doing vertical soundings the work productivity depends on the step of measurements and the number of parameters measured. When measuring one parameter with the step of 10 cm one operator in 1 working day can perform up to 1000 running meters of soundings. When measuring one parameter with the step of 1 m one operator in 1 working day can perform up to 10,000 running meters of soundings. Taking into account at least 4-5 parameters usually measured at one location, one operator in one day can perform a comprehensive sounding with the step of 10 cm to the depth of 250 m and with the step of 1 m to the depth of 2500 m.
The results of soundings allow plotting lithologic columns, geologic sections, structural maps, maps showing bedding depths of underground water and other geologic models.
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