Three important elements of a theory of earthquake prediction are (1) the loading of tectonic stress, (2) the friction law governing fault slip, and (3) the structural heterogeneity of the earthquake source region. From recent seismological studies of the earthquake source process and the structure of source regions, we suggest that the heterogeneity of a fault zone is a 2-dimensional cross-section of the 3-dimensional heterogeneity of the lithosphere in a tectonically active region. We further suggest that the time-varying quality factor of an earthquake source region measured by the local earthquake coda Q may be an earthquake precursor. Because it is easy to measure the coda Q completely and uniformly over a large area, we propose to use the coda Q as a reference to which other precursors may be compared for their reliability check. In addition to the possibility of coda Q being a quantitative and dependable precursor, we have two other sources of optimism for the emergence of a sound theory of practical earthquake prediction. They are (1) the possibility of permanence of asperities and barriers over many repeated earthquakes on a given fault segment, and (2) the possibility of extrapolating the friction law developed in the laboratory to an earthquake fault using results from the study of rupture processes and recurrence phenomena on the fault.
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- Theory of Earthquake Prediction with Special Reference to Monitoring of the Quality Factor of Lithosphere by the Coda Method
- Springer Netherlands