11:00 AM - 11:20 AM
[SEM15-12] Development and Field Validation of a New Magnetotelluric Receiving System in Taiwan
★Invited Papers
Keywords:Magnetotelluric, Carbon Capture and Storage, Geothermal
The magnetotelluric (MT) method utilizes natural electromagnetic sources to observe the electrical structure of the subsurface. By adjusting the measurement duration and signal frequency, the target exploration depth can be effectively controlled. This characteristic makes the MT method particularly suitable for large-scale and deep subsurface investigations, such as site evaluations for carbon dioxide sequestration and geothermal resource assessments. In Taiwan, the high cost of commercial MT receiving systems has led to limitations in instrumentation capacity. To solve this issue and develop a recording system better suited to local research needs, the Industrial Technology Research Institute (ITRI) has developed a prototype of the ITRI-MT receiving system and continues to enhance its performance. This study focuses on optimizing the electric field reception circuit of the ITRI-MT system to improve the stability and accuracy of electric field signal recordings. Enhancements include optimizing the signal amplifier design, adjusting ADC input impedance, and strengthening electromagnetic interference suppression, which significantly reduces system noise. In laboratory tests, a fixed-frequency signal source was used to evaluate the coherence between electric and magnetic field signals. The results showed a high coherence between the two orthogonal signals, confirming the system’s reliability. Additionally, in field tests, synchronized data recordings were conducted using both the ITRI-MT system and the commercial system. The results demonstrated similar resistivity and phase curves between the two systems, verifying that the ITRI-MT system can accurately record and analyze magnetotelluric signals.