Magnetotelluric (MT) and audio-magnetotelluric (AMT) methods were applied to clarify the deep geological structure in a coal-mining area in Kushiro, southeastern Hokkaido, Japan. These methods are effective in surveying to deep. Onedimensional inversion was applied to the measurement data obtained in the MT and AMT surveys to estimate the resistivity distributions in the study area. In addition, the one-dimensional inversion method was improved to obtain accurate results by including a smoothing factor and Akaike’s Bayesian information criterion. The inversion method revealed that the lowresistivity zones at depths between 100 and 120 m below sea level correspond with the Yubetsu coal-bearing formation and clay layer, and the thickness of Cretaceous strata was estimated to be more than 4000 m. Finally, the dip of the Osotsunai fault was estimated., Hisafumi Asaue, Misahito Sasahara, Toru Yoshinaga, Yuzo Obara, Kagemi Ushida and Hiroyuki Matsumoto., and Obsahuje bibliografii
This paper presents results from the exam ination of flood embankments by means of three geophysical methods: GPR, mutual impedance of loop antennas measurements and D.C. resistivity method. In order to increase measuring accuracy, the mutual impedance measuring system works at a high frequency. Parameters of mutual impedance measuring system were presented. A method of mutual im pedance measurement results was described. Flood embankments examination results showed that the simultaneous use of few geophysical methods increases accuracy of inhomogeneities detection in near-surface structure of the ground., Remigiusz Mydlikowski, Grzegorz Beziuk and Adam Szynkiewicz., and Obsahuje bibliografické odkazy
A method of determination the apparent resistyvity of the ground’s near-surface la yers from measurements of the mutual impedance of a loop antenna system operating at a high frequency is presented. An analysis of the sensitivity of mutual impedance to variation in the parameters of conducting half space at different frequencies had been carried out. Additionally influence of displacement current on measured mutual impedance values was discussed. A frequency of measuring system was selected in order to obtain a high sensitivity of the measuring system to detection inhomogeneities characterised by small dimensions and low apparent resistyvity contrast. The measuring system and the method of interpreting measurement results were described. The results of field measurements were presented., Grzegorz Beziuk and Remigiusz Mydlikowski., and Obsahuje bibliografické odkazy