Two-Dimensional Interpretaion of Mt Data from Mid-Mountain Area of Jeju Island, Korea

Abstract

Two-dimensional magnetotelluric (MT) surveys have been carried out at the mid-mountain area of Jeju Island to figure out any possible structures or evidences for remnant deep geothermal energy. Though numerous drillings have been performed in Jeju Island for development of ground water, the wells are mostly located along the coast lines or at low altitude area, but can hardly be found on the mid-mountain area. Two-dimensional (2-D) inversion of MT data for four survey lines surrounding the Halla mountain showed a thick layer having around 10 ohm-m in the depth of a few hundred meters throughout the survey area, which can be considered as the unconsolidated sedimentary layer and the marine originated sedimentary layer. They also showed a conductive anomaly extending to more than 2 km depth at the central part of each survey line, which can possibly be related with old volcanic activities during the formation of Mt. Halla. Further geological/ geophysical investigations will be followed.