Rockburst Research Applied to Nuclear Event Discrimination

摘要

Rockbursts produce seismic signals that are similar to those associated with near surface earthquakes and explosions. Some of the methods developed for source mechanism studies also encompass imaging techniques appropriate for nuclear event verification, and, as a result, have implications for the Comprehensive Test Ban Treaty (CTBT). We have conducted experiments to detect a relationship between BN and stress in magnetite-rich rocks. These experiments were performed by applying uniaxial loading from 4500N to 55000N to cylindrical core samples of magnetite-rich rocks obtained from the Stillwater Complex in Montana. A pick-up coil was used to detect the BN pulses and an electromagnet was used to magnetize the samples. BN pulses were recorded during a specified time interval for each increment of loading. We have observed a linear increase in the number of BN pulses with increased loading. Ongoing research is focused on refining the experimental procedure to increase the bandwidth of recording and eliminate possible sources of noise in the experiments. The results of this study might help us to understand the nature of the remagnetization that often accompanies large-scale tectonic events. Moreover, this study could lead to a method of nondestructive testing to determine state of stress at mine walls.