INTERPRETATION OF CSAMT SINGLE-COMPONENT DATA

Following the Magnetotellurics method (MT), the apparent resistivity of the Controlled Source Audio-frequency Magnetotellurics (CSAMT) is usually derived from the ratio of electric field and magnetic field. For CSAMT, as the source power current density is known, both of the electric and magnetic field components are related to the resistivity of the earth. The apparent resistivity can be obtained from the single electric field or magnetic field. In this paper, we put forward the inversion and interpretation methods for single-component data of CSAMT after analysing the data features. During the curve fitting inversion, in order to increase the number of the inverted layers, the number of frequency of curves is regarded as the inversion earth layers number. The all-zone electric component apparent resisitivity inversion is developed. Then, the phase is introduced into the inversion process to omit the effect of static displacement. The field observation in water-filled mined-out space in Shanxi Province is used to verify the effectiveness of the new interpretation method.