EarthRef.org Reference Database (ERR)
Development and Maintenance by the EarthRef.org Database Team

Detailed Reference Information
Liu & Ahrens 1997
Liu, C. and Ahrens, T.J. (1997). Stress wave attenuation in shock-damaged rock. Journal of Geophysical Research 102: doi: 10.1029/96JB03891. issn: 0148-0227.

The velocity and attenuation of ultrasonic stress waves in gabbroic rock samples (San Marcos, California) subjected to shock loading in the 2 GPa range were studied. From P wave velocity measurements we determined the damage parameter Dp and crack density &egr; of the samples and related these to the attenuation coefficient (quality factor) under dynamic strains of 2¿10-7 and at a frequency of 2 MHz using the ultrasonic pulse-echo method. A fit to the data yields the P wave spatial attenuation coefficient at a frequency of 2 MHz, αp(Dp)=1.1+28.2Dp (decibels per centimeter). From the relation between the attenuation coefficient and quality factor, the quality factor Q is given by Q-1=0.011(1+25.6Dp)(1-Dp)1/2. Using O'Connell-Budiansky theory relating crack density to velocity, the parameter in Walsh's theory was determined based on experimental data. An approximate method is also proposed to estimate the average half-length of cracks based on the attenuation measurements.¿ 1997 American Geophysical Union

BACKGROUND DATA FILES

Abstract

Keywords
Physical Properties of Rocks, Wave attenuation, Physical Properties of Rocks, Fracture and flow
Journal
Journal of Geophysical Research
http://www.agu.org/journals/jb/
Publisher
American Geophysical Union
2000 Florida Avenue N.W.
Washington, D.C. 20009-1277
USA
1-202-462-6900
1-202-328-0566
service@agu.org
Click to clear formClick to return to previous pageClick to submit