This network encompasses several magnetotelluric surveys carried out under the NSF-funded Electromagnetic Studies of the Continents (EMSOC) award from 1996 to 2007. Studies were carried out by various institutions and principal investigators. Network includes studies in the United States, Argentina, China, Kyrgyzstan, and Taiwan. Authors listed are the principal investigators for those surveys included. Corresponding magnetotelluric transfer functions for many of these surveys are available on SPUD under Project='EMSOC' and Project='Argentina.' A primary works citation for each component survey is included below.