Applied geophysics / Прикладная геофизика

Geophysics, as its name indicates, has to do with the physics of the earth and its surrounding atmosphere. Gilbert’s discovery that the earth behaves as a great and rather irregular magnet and Newton’s theory of gravitation may be said to constitute the beginning of geophysics. Mining and the search for metals date from the earliest times, but the scientific record began with the publication in 1556 of the famous treatise De re metallica by Georgius Agricola, which for many years was the authoritative work on mining. The initial step in applying geophysics to the search for minerals probably was taken in 1843, when Von Wrede pointed out that the magnetic theodolite, used by Lamont to measure variations in the earth’s magnetic field, might also be employed to discover bodies of magnetic ore. However, this idea was not acted on until the publication in 1879 of Professor Robert Thalén’s book On the Examination of Iron Ore Deposits by Magnetic Methods. The Thalén-Tiberg magnetometer manufacture in Sweden, and later the Thomson—Thalén instrument, furnished the means of locating the strike, dip, and depth below surface of magnetic dikes. The continued expansion in the demand for metals of all kinds and the enormous increase in the use of petroleum products since the turn of the century have led to the development of many geophysical techniques of ever-increasing sensitivity for the detection and mapping of unseen deposits and structures. Advances have been especially rapid since World War II because of major improvements in instrumentation and the widespread application of the digital computer in the processing and interpretation of geophysical data. <...>