HR: 1330h
AN: S32B-0844    [PDF]
TI: Development of a Suite of Seismic Discriminants for Characterizing Mining Explosions in Southeastern Arizona
AU: * Renwald, M D
EM: mrenwald@lanl.gov
AF: Southern Methodist University, Department of Geological Sciences, PO Box 750395, Dallas, TX 75275 United States
AU: Stump, B W
EM: bstump@mail.smu.edu
AF: Southern Methodist University, Department of Geological Sciences, PO Box 750395, Dallas, TX 75275 United States
AU: Hayward, C T
EM: hayward@smu.edu
AF: Southern Methodist University, Department of Geological Sciences, PO Box 750395, Dallas, TX 75275 United States
AU: Zhou, R
EM: rzhou@mail.smu.edu
AF: Southern Methodist University, Department of Geological Sciences, PO Box 750395, Dallas, TX 75275 United States
AB: Effectively monitoring a nuclear testing moratorium requires the ability to discriminate between earthquakes and explosions. At small magnitudes (below mb 3.5), it is especially crucial to further refine source characterization, distinguishing between different types of explosions, specifically mining explosions from nuclear and chemical events. The characteristics of mining explosions and their respective seismic signatures can be quite variable due to blasting procedures and source geometry. It becomes important, then, to develop a set of regional discriminants that can account for such variability and are robust, reliable, and globally transportable. To examine this problem, we initially focus on mining explosions at Morenci, Arizona. Two recent experiments (Source Phenomenology Experiments (2003) and Morenci Delay-Fired Experiments (2001)) provide ground truth information for different types of mining explosions: single-fired, delay-fired, and overlapping multiple explosions that occur in different geometric configurations and in different mine locales. Regional waveforms from Morenci illustrate a number of issues that must be taken into consideration when developing discriminants. First, high scatter due to source timing effects is seen in regional amplitudes; large, long duration shots produce smaller high frequency amplitudes as compared to smaller, shorter duration shots. This effect makes the establishment of magnitude-yield relationships for mining explosions problematic. Second, closely spaced shots ($\sim$100 m) can produce different waveforms due to source timing effects, as can shots with similar timing patterns detonated in different parts of the mine (distance ranges from 1 to 3 km).
DE: 7203 Body wave propagation
DE: 7219 Nuclear explosion seismology
SC: Seismology [S]
MN: 2003 Fall Meeting