NOVOSIBIRSK, November 14. /TASS/. The Russian Academy of Sciences' Institute of Petroleum Geology and Geophysics developed the technology of rapid monitoring of frozen soils to observe changes in the soil in real time and to respond more quickly to them, cutting risks of buildings and roads' destruction, reads Science in Siberia, the Academy's Siberian Branch's official publication.
Normally, temperature monitoring in the soil is carried out by drilling wells and placing temperature sensors into them. However, the traditional method has a significant disadvantage: thermal fluctuations reach the sensor rather slowly, thus information cannot be obtained quickly enough.
"Our idea is as follows: we drill shallow wells of a few to dozens of meters, and install sensitive sensors. We use two types of generators: traditional induction coils and less common current lines. The basic concept is to place a set of transmitters into one well, and receivers - into the neighboring one. This way we can scan the space between the two wells to accurately determine changes there," the publication quoted Igor Mikhailov, the institute's representative, as saying.
It is also possible to place the generator on the surface, where the area between the source and the underground sensors is visible, the scientist continued. The signal is given by short electromagnetic pulses, and equipment records the reaction. The technology pays special attention to conditions of the upper thawed layer. Anyway, it is universal and may be used in regions with different soil types.
"The method allows us to monitor frozen soils in real time. By using special equipment, we can track the soil's changes in electrical resistance. As the temperature increases, the resistance decreases in proportion to the degree of the substance's thawing," he said.
Monitoring tools
Scientists use computer software to receive visual graphs and maps of the resistance distribution to see quickly possible risk areas and to decide promptly on further actions. For example, if a house or other structure becomes unsafe for operation, they may recommend evacuation of people or the structure's reconstruction. Thus, the pulse monitoring technology helps to prevent accidents and minimize possible damage.
Scientists say collected data may be sent remotely, for example via GPS or mobile networks directly to the working group. The installed sensors will be able to send observation results directly to the office, where specialists will process and analyze them.
"We are conducting practical tests: we use equipment settings based on mathematical modeling, and at the same time we test them with physical experiments. The purpose of these experiments is to see how well the idea will work in real conditions. Our preliminary estimations show that implementation is possible, and now we want to make sure in practice that it is effective," the scientist said.