This is a compilation of data acquired during the Conference on Disarmament, GSE (Group of Scientific Experts) Second Technical Test from April 22 to June 2, 1991. This data set includes Seismic Parameter and Waveform data from two CD-ROMs, and specifically contains parametric data from 3,000 seismic events recorded by 60 globally distributed stations over a 42 day period in the spring of 1991, with the purpose of evaluating the success of GSETT-2.