Related Experiment Video
Updated: Aug 8, 2026

Comprehensive Characterization of Extended Defects in Semiconductor Materials by a Scanning Electron Microscope
Published on: May 28, 2016
Attenuation of seismic waves by grain boundary relaxation
1Institute of Geophysics and Planetary Physics, University of California, Los Angles, Calif. 90024.
Abstract:
Experimental observations of the attenuation of elastic waves in polycrystalline ceramics and rocks reveal an attenuation mechanism, called grain boundary relaxation, which is likely to be predominant cause of seismic attenuation in the earth's mantle. For this mechanism, the internal friction (the reciprocal of the "intrinsic Q" of the material) depends strongly upon frequency and is in good agreement with Walsh's theory of attenuation (J. Geophys. Res., 74, 4333, 1969) in partially melted rock. When Walsh's theory is extended to provide a model of the anelasticity of the earth, using the experimental values of physical parameters reported here, the results are in excellent agreement with seismic observations.
More Related Videos
Related Concept Videos
Speed of Sound in Solids and Liquids
Atomic Nuclei: Nuclear Relaxation Processes
Atomic Nuclei: Types of Nuclear Relaxation
In spin–lattice or longitudinal relaxation, the excited spins exchange energy with the surrounding lattice as they return to the lower energy level. Among several mechanisms that contribute to spin–lattice relaxation, magnetic dipolar interactions are significant. Here, the excited nucleus transfers energy to a nearby...
Elastic Strain Energy for Normal Stresses
If...
Elastic Strain Energy for Shearing Stresses
Unsoundness of Aggregate due to Volume Change

