Regional Event Identification Research in Asia
Abstract
Recent event identification efforts at Los Alamos National Laboratory (LANL) have focused on mining event ground-truth data collection in central Asia and testing far-local to near-regional discriminants using earthquakes, mining explosions, and single-charge chemical explosions. Our mining event efforts have identified over 20 mines and more than 1,000 mining explosions from around the former Soviet nuclear test site (KTS) in eastern Kazakhstan. Using the Kazakh National Data Centre (KNDC) bulletin from 2002 to 2007 and waveforms recorded at station KURK and array MKAR, we combined time-of-day seismic-event analysis, waveform cross correlations, seismic-event location methods, and image analysis to identify active mines. From our previous, but more limited studies, we had assumed mining explosions in eastern Kazakhstan occur only between about 8 AM and 8 PM local time. However, our latest study, using several thousand events, reveals that some mines shoot near midnight local time. Thus, we concluded that only during the hours of 21, 22, and 23 GMT (3, 4, and 5 AM local time) can we assume that the small events from this region are probable earthquakes. Using this assumption, we selected 8 events within about 250 km of station KURK as earthquakes, and we selected about 250 mining explosions from three mines for discrimination analyses. In addition, we gathered all available depth-of-burial (DOB), hole-closing, and tunnel-closing single-charge chemical explosions that occurred at KTS from 1997 to 2000 and were recorded at KURK. The single-charge chemical events occurred within about 125 km of KURK. From published reports, we have flagged three of these events as fully contained. For the mining events, we do not know the shooting practices, such as delayed-firing along rows of shotholes. Using the events described above, we tested spectral-ratio and phase-ratio body-wave amplitude discriminants.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2008
- Accession Number
- ADA516281
Entities
People
- George E. Randall
- Hans E. Hartse
- Stephen J. Arrowsmith
Organizations
- Los Alamos National Laboratory