Shock Propagation in Crustal Rock
Abstract
The shock Hugoniot and adiabatic release curves of sedimentary rocks display a range of different behaviors that affect the decay of shock waves propagating away from a confined source. Many of the minerals making up sandstones, shales, and limestones undergo phase transitions when shocked to pressures of interest to studies of coupling of energy from explosive sources into far field seismic waves. Both sandstones and limestones have been observed to exhibit elastic precursors and multiple wave behavior at shock velocities up to 3.7 km/s and 5.7 km/s, respectively Ahrens and Gregson, 1964. Hysteresis in the shock-release paths of materials results in irreversible energy deposition, thus depriving the shock wave of energy required to drive its propagation and resulting in a more rapid decay and less efficient coupling to far field waves than expected from geometrical effects alone. Thus, data constraining this behavior in rocks are essential for determining the cavity volumes for various degrees of decoupling for different lithologies. The behavior of most sedimentary rocks during adiabatic release has not been experimentally investigated to a significant extent. Our objective was to obtain experimental data for shock and release behaviors of elastic and carbonate sedimentary rocks and use those data along with data from other sources, to develop a theoretical model of the hysteretic shock-release paths of these rocks. We use this model to constrain the energy deposited irreversibly in these rocks by the passage of shock and release waves. The release model we use is a modification of that used by Sekine et al. 1993, submitted for granite.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 08, 1993
- Accession Number
- ADA270148
Entities
People
- Thomas J. Ahrens
- William W. Anderson
Organizations
- California Institute of Technology