Improvements to a Major Digital Archive of Seismic Waveforms from Nuclear Explosions

摘要

This project took advantage of Soviet-era digital seismic recordings, all of them made at the Borovoye Geophysical Observatory in Kazakhstan, of ground motion from numerous underground nuclear explosions that occurred in Eurasia over a period of three decades, from 1966 to 1995. We have prepared these recordings in a modern format, to make them usable by the seismic monitoring community for numerous ongoing and future studies of Earth structure, attenuation characteristics, and explosion source physics including source representation by body force equivalents and associated source spectra. To produce the newly-formatted signals required major efforts at Los Alamos National Laboratory to remove glitches in the original records, and at the Lamont-Doherty Geophysical Observatory to obtain instrument responses. Three different recording systems operated at Borovoye: the KOD system from 1973 to 1990; the SS system from 1973 to 1990; and the TSG system from 1974 to 1995. Each system included channels of low-gain and high-gain recording; and each system included vertical, north/south, and east/west channels. In this project, particular attention was paid to data from the KOD and SS systems, which had not previously been deglitched and instrument-corrected. We have prepared waveforms from nuclear explosions at the following five test sites: Balapan (1269 traces), Degelen (1146 traces), and Murzhik (160 traces), all in Kazakhstan on the Semipalatinsk Test site; Novaya Zemlya (461 traces) in Russia; and Lop Nor (120 traces) in China; and also from many Peaceful Nuclear Explosions (552 traces) in Russia. Although the dynamic range of specific channels is limited by the low number of bits in the recording system, the scientific content of the signals across the many different channels approaches that for modern recording systems. The improved Borovoye archive now provides masignals that modern monitoring networks.