HR: 0800h
AN: U21B-0821    [Abstracts]
TI: Predicting the Stochastic Properties of the Shallow Subsurface for Improved Geophysical Modeling
AU: * Stroujkova, A
EM: ana@westongeophysical.com
AF: Weston Geophysical Corporation, 57 Bedford St., Suite 102, Lexington, MA 02420 United States
AU: Vynne, J
EM: jvynne@tbirdpac.com
AF: Thunderbird Mining Systems, 2609 - 151st Place N.E., Redmond, WA 98052 United States
AU: Bonner, J
EM: bonner@westongeophysical.com
AF: Weston Geophysical Corporation, 57 Bedford St., Suite 102, Lexington, MA 02420 United States
AU: Lewkowicz, J
EM: jiml@westongeophysical.com
AF: Weston Geophysical Corporation, 57 Bedford St., Suite 102, Lexington, MA 02420 United States
AB: Strong ground motion data from numerous explosive field experiments and from moderate to large earthquakes show significant variations in amplitude and waveform shape with respect to both azimuth and range. Attempts to model these variations using deterministic models have often been unsuccessful. It has been hypothesized that a stochastic description of the geological medium is a more realistic approach. To estimate the stochastic properties of the shallow subsurface, we use Measurement While Drilling (MWD) data, which are routinely collected by mines in order to facilitate design of blast patterns. The parameters, such as rotation speed of the drill, torque, and penetration rate, are used to compute the rock's Specific Energy (SE), which is then related to a blastability index. We use values of SE measured at two different mines and calibrated to laboratory measurements of rock properties to determine correlation lengths of the subsurface rocks in 2D, needed to obtain 2D and 3D stochastic models. The stochastic models are then combined with the deterministic models and used to compute synthetic seismic waveforms.
DE: 0902 Computational methods: seismic
DE: 0999 General or miscellaneous
DE: 3235 Persistence, memory, correlations, clustering (3265, 7857)
DE: 3265 Stochastic processes (3235, 4468, 4475, 7857)
SC: Union [U]
MN: Fall Meeting 2005