Magnetotelluric Systems at PASSCAL

Magnetotelluric (MT) methods are used to produce conductivity models of the crust and upper mantle through the recording of geoelectric and geomagnetic field variations at the Earth's surface. Depending on the period of the recordings, these methods can provide results from a few hundred meters depth (short period) to 30 km or deeper (long period). Conductivity is a physical property, which is complementary to seismic velocity, and which is very sensitive to the presence of fluids. When seismic and MT data sets are measured together, the additional data can dramatically improve determinations of the structure of the crust and mantle.  

PASSCAL is actively developing MT resources for PIs. In addition to Borin Ag-AgCl2 Electrodes, LEMI-039 Flux Gates, and induction coils (in procurement), PASSCAL has long-period LEMI-424 dataloggers available. An initial set of 3 wideband MT dataloggers is to be purchased in the first quarter of 2021, with a full complement of 20 wideband loggers to be acquired by 2023. These instruments are available through the conditions stated in the PASSCAL Instrument Use Policy.