Ninth International Conference on Permafrost ... - IARC Research

Low-Frequency Sounding During the Gas Line Engineering Investigations in theArea of the Transition Through Baidaratskaya BayA.V. KoshurnikovMSU-Geophysics, Ltd.Yu.D. ZykovThe Moscow State UniversityYu.V. KulehsovPeter Gaz, Ltd.The main task of this geophysical research was thelateral exploration of frozen and thawed soils in the pipelayingzone. In that regard, special attention was given tointrasoil ice, thawed soils, and cryopeg detection. Verticalelectric explorations were used in the chosen gas pipeline.Vertical electric sounding by a direct current (VES) (Fig. 1),frequency electromagnetic sounding (FS) (Fig. 2), and timedomain sounding (TEM) (Fig. 3) were carried out.To perform the FS, a recently-made hardware system,namely HF-EM, was used. The system includes the generationof square signals with a combination of a discreet set offrequencies from 4 up to 512 kHz. The measuring deviceand the multiloop frame antenna work simultaneously withthe generator. While sounding with VES, a bilateral threeelectrodesystem was used.The maximum open pit was 100 m, while the FS soundingdistance between the generator and measuring device was40 m. It takes about 1 minute to measure the signature withthe help of FS sounding. Each of these signatures, as EFigure 3. TEM. Jamal, 2007.Figure.1. VES. Ural, 2006.Figure 2. FS. Jamal, 2007.Figure 4. Geoelectric cross section (Ural).145