Software to Process and Preserve Legacy Magnetotelluric Data

Release Date:
Image: Full View of the San Andreas Fault

Full view of the ground with the San Andreas fault running through the middle of the image.

(Credit: Scott Haefner, U.S. Geological Survey. Public domain.)

The U.S. Geological Survey (USGS) Crustal Geophysics and Geochemistry Science Center (CGGSC) collaborated with the USGS Data at Risk (DaR) team to develop this official USGS software release, a set of Python scripts that create Electronic Data Interchange (EDI) format EDI files from ASCII formatted time-series and cross-powers magnetotelluric data based on the Society of Exploration Geophysicists MT/EMAP Data Interchange Standard Revision 1.0, December 14, 1987. 

These scripts were run against 1990 Truck mount MT Cross power and Time series files from the data release: Magnetotelluric Data from the San Andreas Fault, Parkfield CA, 1990 (

To run against other magnetotelluric data, changes may have to be made due to potential historical variations in ASCII file formats. This script is designed as a template to use when creating EDI files from similar Magnetotelluric data. All input (ASCII) and output (EDI) files for the code, along with all other resources required to run the code are located in the Validation_Resources folder of the software repository (See "Download Software" button below).