Controlled Source Magnetotelluric Survey of Mabini Geothermal Prospect, Mabini, Batangas, Philippines

Abstract

Controlled Source Magnetotelluric (CSMT) survey was conducted over the Mabini Geothermal Prospect (MBGP) by Geothermal Division staff in 2000. The purpose of the survey is to characterize the geothermal system underneath the prospect and to test the reliability of the newly repaired CSMT equipment from Japan. CSMT is frequency domain electromagnetic sounding system that utilizes horizontal dipole as an artificial signal source located 4-6 kilometer away from the receiver.
Results of the survey show probable existence of geothermal resource beneath the Hulo Caldera Collapse. Fault structures generally control the resistivity structure of the prospect. This finding is consistent with the earlier study of PNOC-EDC on the existent of hydrothermal resource upwelling in Mt. Binaderahan. However this is still premature and may not be conclusive due to lack of comprehensive geophysical and drilling studies to be used as a basis for correlation. Geophysical studies done in the area were reconnaissance in nature and random stations are a considerable distance apart from each other.