Application of magnetotelluric survey for development of deep geothermal water at Seokmo Island, Korea

석모도 지열수 개발을 위한 자기지전류탐사의 적용

  • 이태종 (한국지질자원연구원 지하수지열연구부) ;
  • 송윤호 (한국지질자원연구원 지하수지열연구부) ;
  • 박덕원 (한국지질자원연구원 지하수지열연구부)
  • Published : 2008.06.01

Abstract

A magnetotelluric survey and geological survey have been performed to delineate deeply extended fracture systems at the geothermal field in Seokmo Island, Inchon, Korea. One borehole(BH-1) succeed to meet a large fracture system at the depth of 750 m where approximately $72^{\circ}C$ geothermal water is overflowing, while the other borehole(BH-2), which is about 200 m eastward from BH-1, failed to develop enough geothermal water even at the depth of 1,200m. Though there have been so many electric noise sources around the survey region, good quality of MT data above 1 Hz could be obtained with careful installation, remote reference processing. Inversion of MT data for two lines roughly perpendicular to the two major lineaments respectively show that the two lineaments are related to the fracture systems that are extended at least down to 1.5 km depth and inclined eastwards. From the interpretation, additional drilling for BH-2 is recommended and finally meet the fracture systems at the depth of 1,280 m and resulted in overflow of large amount of geothermal water of temperature $69.4^{\circ}C$ from BH-2.

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