EMinar 2.20: Ian Ferguson - “Nuts and bolts” of magnetotelluric instrumentation and field-work

Acquisition of high-quality magnetotelluric (MT) data requires detailed planning, sensible site selection, suitable equipment, careful field procedures, high signal levels and low noise levels, and sometimes good luck. It is easy to collect poor quality MT data sets that do not reward the time and cost of the acquisition, and that limit subsequent data analysis and interpretation. In this tutorial, based on a chapter of The Magnetotelluric Method: Theory and Practice, we examine some basics of MT instrumentation and data collection. The presentation is designed principally for those just setting out on their MT journey. What are characteristics of good magnetometers and electrometers? How do we record magnetic and electric fields that represent Earth responses and allow computation of accurate MT impedances? What are best practices in MT field-work? Every contribution from MT starts with the data collection, so understanding instrumentation and field procedures is a critical aspect of all MT studies.