Frequency dependence of elasticity of rock-test of seismic velocity dispersion

Brennan B.J. and Stacey F.D. (1977) Frequency dependence of elasticity of rock-test of seismic velocity dispersion. Nature, 268 5617: 220-222. doi:10.1038/268220a0


Author Brennan B.J.
Stacey F.D.
Title Frequency dependence of elasticity of rock-test of seismic velocity dispersion
Journal name Nature   Check publisher's open access policy
ISSN 0028-0836
Publication date 1977-01-01
Sub-type Article (original research)
DOI 10.1038/268220a0
Open Access Status Not yet assessed
Volume 268
Issue 5617
Start page 220
End page 222
Total pages 3
Subject 1000 General
Abstract LINEAR theories of attenuation of acoustic or seismic waves in media, such as rocks, which are characterised by constant or nearly constant Q factors (fractional energy loss per cycle equals 2π/Q) imply velocity dispersion and, therefore, frequency dependence of elasticity. The effect is small, corresponding to a change of order 1 % over the period range of seismological interest (1 s to 1 h), and is consequently difficult to observe. However, it leads to an internal inconsistency in the development of earth models by inversion of free oscillation data and to discrepancies between these models and body wave data1-3. It is a matter of considerable geophysical interest to resolve the problem. Validity of the linearity assumption has been questioned4 but we are now observing elliptical hysteresis loops in basalt and granite samples subjected to sinusoidal strains of order 10 -6 and this is strong evidence that attenuation does become a linear phenomenon at low strain amplitudes. But whether or not perfect linearity applies, a direct demonstration of body wave dispersion is the most satisfying indication that earth model studies need revision.
Q-Index Code C1
Institutional Status Unknown

Document type: Journal Article
Sub-type: Article (original research)
Collection: Scopus Import - Archived
 
Versions
Version Filter Type
Citation counts: Scopus Citation Count Cited 44 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Tue, 13 Sep 2016, 12:38:06 EST by System User