REGIONAL SEISMIC RECORDINGS OF THE SOVIET NUCLEAR-EXPLOSION OF THE JOINT VERIFICATION EXPERIMENT

During August and September, 1988, the United States and the Soviet Union conducted a Joint Verification Experiment in which each country was permitted to observe a nuclear explosion at the other country's test site using hydrodynamic means. We have seismically recorded the Soviet explosion at four stations at regional distances (Δ ≤ 750km), and here report those observations. The peak‐to‐peak particle motion in the P‐wave varied from 7.54×10−1 cm/sec at Δ ≈ 160 km to 1.02 × 10−2 cm/sec at Δ ≈ 740 km. The average mb(Lg) was 5.97 corresponding to a yield of 118 KT, based on the NTS mb(Lg) ‐ yield relation of Patton [1988], The average Pn corner frequency of the Soviet explosion was 4 Hz with evidence of a second corner at about 0.7 Hz. Both of these corners could be affected by spall. Near‐regional seismograms of the Soviet JVE explosion show a large arrival within the Lg phase on the transverse component at all four sites. This may correspond to tectonic release accompanying the explosion, or to the effects of anisotropy on seismic wave propagation. © 1990 by the Chinese Geophysical Society