The focus of this project is on supporting and extending capabilities of "ModEM", a modular system for inversion of electromagnetic (EM) geophysical data which has been developed over the past few years at Oregon State University. The code has been applied to inversion of a range of EM geophysical datasets, including 2D and 3D magnetotellurics (MT), geomagnetic observatory data for global deep mantle conductivity studies, and simple controlled source EM, and preliminary versions were made available to expert academic users during the initial development phase. Through this project we are extending and "hardening" ModEM, and maintaining and supporting its use for a broader community of users. Our primary initial focus is on support of 3D MT capabilities (which are most developed in ModEM, and of the greatest academic interest), but we are also building on the more general capabilities of ModEM to support inversion of CSEM data, and joint inversion of multiple EM (and ultimately other) data types. In addition to development and maintenance of software, we provide training in its use, offering short courses on 3D MT inversion and interpretation, and maintaining a web presence where the community of ModEM users can discuss with us, and each other, problems and solutions as they arise.
Making ModEM widely available to the broadest community possible, supporting further development, and providing resources for education and community interaction, all contribute substantially to the ongoing 3D revolution in EM geophysics, which will ultimately enable new discoveries in basic and applied Earth science. Wide and free availability of advanced inversion codes facilitates expansion of the community of experienced 3-D inversion users, and will accelerate development within this community of understanding of the appropriate uses (and limitations) of these now novel 3-D interpretation methods. EM methods have important applications in industry and in the applied environmental sciences. This project is helping to develop capacity for these applications, supporting development of practical and robust software and knowledgeable and trained users.