Observations of dilatancy-induced polarization anomalies and earthquake prediction
Abstract
Much of the search for earthquake prediction schemes has centred on the expectation that rocks in the impending source area will show dilatancy: the opening of cracks at high stress-levels. Recent developments in the theory of seismic wave propagation in cracked media1 demonstrate that shear-wave splitting will occur in seismic-wave propagation through cracked structures, when the cracks have any overall alignment. This splitting causes polarization anomalies in the seismograms, and it has been suggested1 that dilatancy, induced by the build-up of stress before earthquakes, might be recognized and monitored by analysis of these anomalies. We present here new observations which support this hypothesis.
- Publication:
-
Nature
- Pub Date:
- August 1980
- DOI:
- 10.1038/286874a0
- Bibcode:
- 1980Natur.286..874C