Dizhi lixue xuebao (Jun 2023)
A brief talk on comprehensive crustal activity observation technology of deep-holes
Abstract
Under the action of the Earth’s inner dynamics, the lithosphere shapes different types of the Earth’s surface, and the crustal stress state and its dynamic change law are captured by the comprehensive observation technology of drilling crustal activity. It is an important way for human beings to understand the internal dynamic process of the Earth and study the mechanism of inner dynamic geological hazards. The contribution of developed countries such as Japan, the USA, and the IODP International Cooperative Research Program to the development of integrated borehole crustal observation technology is summarized in this paper. The paper also systematically reviews the development history and present situation of borehole strain observation technology and borehole strain observation instrument in China. Especially since the 13th Five-Year, under the background of the national strategy of deep-sea exploration, the China Geological Survey Bureau (CGS), the China Earthquake Administration, and other systems have successively carried out research and development of the integrated geophysics observation system in wells, and have been put into use in integrated land and sea observation stations. The Institute of Geomechanics has successfully developed an integrated geophysics observation system for crustal activity using the key techniques of system integration. The system has a variety of strain, tilt, seismic, geomagnetic, geothermal, pore pressure, other sensors, and 16 components capable of observing crustal deformation, stress, strain, tilt, earthquake, and their induced geodynamic changes in the lithosphere, such as geotemperature, hydrology, geoelectricity, geomagnetism, etc. It has been put into use in Shandan (installed depth 253 m) and Pingwu (WFSD-4, 1600 m) observatories in Gansu and Sichuan provinces and has achieved initial results. It is a milestone for our comprehensive crustal activity observation technology to break through the 3000-meter-deep well in the future. It can provide vital information for geodynamics research, safe exploitation of deep mineral and geothermal resources, and prediction of internal dynamic geological hazards. At the same time, based on the national strategy of deep-sea exploration in the 14th Five-year, the future development direction of integrated observation system of deep-well crustal activity is pointed out.
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