Title: CLARIFYING GEOLOGICAL STRUCTURE FOR COAL AND MARSH GAS DEVELOPMENT USING MAGNETOTELLURIC METHOD |
Authors: Asaue Hisafumi, Sasahara Masahito, Yoshinaga Toru, Obara Yuzo, Uchida Kagemi and Matsumoto Hiroyuki |
DOI: 10.13168/AGG.2013.0015 |
Journal: Acta Geodynamica et Geomaterialia, Vol. 10, No. 2 (170), Prague 2013 |
Full Text: PDF file (2.4 MB) |
Keywords: apparent resistivity, cretaceous formation, Kushiro city, Osotsunai fault, Harutori fault |
Abstract: 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. |