[en] Regional seismic records for eleven underground nuclear explosions were processed and analyzed (empirically) in a search for source and path related patterns in the signals. These nuclear tests were conducted between August, 1979 and April, 1980; all were located in Yucca Flat at the Nevada Test Site (NTS). The seismic signals generated by these explosions were recorded on the LLNL four-station network, located at distances of 200 to 400 km from the NTS. Amplitudes were measured for consistently recorded vertical component body waves, and for vertical and transverse components of surface waves. Correlation between phase amplitudes was statistically determined, and amplitude ratios were compared for four stations for the same event, and at a single station for the complete set of events. Previous studies have shown that certain amplitude ratios are relatively unaffected by the size of the explosion but sensitive to propagation effects. For this set of events, we do not find a statistically significant change in the ratio of Pg:Lg due to different propagation paths to the four stations. We do, however, find increased variability in the amplitude measurements for the smaller events in the population considered in this study