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Accession Number:
ADA516348
Title:
A Suite of Discriminants for Ground-Truth Mining Events in the Western U.S. and Its Implications for Discrimination Capability in Russia
Descriptive Note:
Conference paper
Corporate Author:
LOS ALAMOS NATIONAL LAB NM
Report Date:
2008-09-01
Pagination or Media Count:
11.0
Abstract:
The problem of identifying mining events has become an important one given the deployment of regional seismic stations in monitoring areas of interest, particularly in countries where mining efforts are significant to the economy. As with other types of regional events, signals from mining events are influenced by the propagation path and local site and receiver effects. Unique to mining explosions, however, are the complex source functions that are representative of the complicated firing sequences and spatial extent utilized in engineering blasts. Many factors contribute to the source function, including grid spacing, inter-row and inter-shot delay times, borehole depth, yield per hole, material casting, and total yield. During this four year study, we have developed a comprehensive database of 150,000 waveforms featuring 2500 mining events and 1300 earthquakes. This database covers mines in the U.S. and in Russia we have focused analysis on two regions events associated with coal mines in Wyoming and regional earthquakes of the Western U.S., as well as mining events and nearby earthquakes in the Altai-Sayan AS region of Russia. Due to extensive collaboration with the largest coal mine in Wyoming and the nation, we have detailed shot information for 1000 mining events, classified into six distinct blast types. We have limited information for events in the AS region based upon contacts with the AS Seismological Expedition. We have applied three discriminants to data from 11 stations and one array in the Western U.S. The first discriminant, time-of-day TOD, assesses the time an event occurs. In general, for our dataset, mining events occur between 9am and 6pm local time, while earthquakes are randomly distributed with respect to time. The second discriminant, amplitude ratios AR, exploits spectral differences between regional phases due to source type. For the Western U.S dataset, results for PgLg 6-8 Hz are highly station centric.
Distribution Statement:
APPROVED FOR PUBLIC RELEASE
