An Analysis of Large Mining Blasts in Wyoming and Central Asia

We have conducted a preliminary analysis of kiloton class, anomalous, mining blasts in Wyoming using IMS seismic data. This research has begun on two fronts. We are examining well documented mine blasts in the Powder River Basin trend in Wyoming using the Pinedale seismic array (PDAR) and the single station ULM. These data are being used with near-regional video, seismic and acoustic data collected by UCSD, LANL, SMU and AFTAC during field experiments in 1996 and 1997. These data are being used to examine differences in the waveforms of mining blasts that are essentially co-located, and detonated with similar planned blasting grids, but for which some have included a significant detonation anomaly (otherwise known as a sympathetic detonation). We are examining coherent and incoherent beams of Pinedale array data in an attempt to detect the large detonations. We are using physical modeling in an attempt to reproduce the waveforms of the anomalous blasts. Our main goal with the modeling is to estimate the explosive yield and timing of the detonation anomalies. Kiloton class mine blasts are not uncommon in numerous regions worldwide such as Wyoming, Kentucky and, at least historically, the Kuzbass mining region in Russia. Recordings of large blasts in the Kuzbass mining region exhibit timeand frequency-domain characteristics below 10 Hz that are similar to those observed in the Wyoming events. In specific, these features include enhanced surface waves and spectral modulations. We tentatively conclude that the discrimination methods we have found to be useful in Wyoming can also be used in this region. In collaboration with Vitaly Khalturin (LDEO) we are seeking ground truth information on large mining blasts in the Altay-Sayan mining region. This exploratory phase will be followed by physical modeling of the events for which we are able to secure adequate ground truth information.