社団法人　物理探査学会
第136回(平成29年度春季)学術講演会

講演要旨(和文) 講演要旨(英文) Magnetotelluric (MT) measurements are divided into Audio Magnetotellurics (AMT), for the high frequency spectrum ca. 10 Hz to 10 kHz, and Magnetotellurics (MT), for the low frequency spectrum ca. 100 Hz to 10-4 Hz. Note the spectra overlap. AMT and MT signals have different origins. AMT and MT signals have large diurnal, seasonal and secular variations of amplitude that may affect specific frequency bands, especially the MT and AMT "dead bands". Because of the nature of those signals, their frequency content and their variation over time, the industry has relied so far on two types of magnetic sensor to capture the AMT and MT spectral ranges. This has defined two different field methodologies that are usually not deployed simultaneously because of the associated costs. We introduce here a new generation broad-band (BMT) induction sensor, the MTC-150, that simultaneously captures AMT and MT signals. This provides the geophysicist with a true broadband A/MT spectrum, with much improved quality in the AMT dead-band, as well as other improvements.