Search for Direct Stress Correlation Signatures of the Critical Earthquake Model

Abstract

We propose a new test of the critical earthquake model based on the hypothesis that precursory earthquakes are ``actors'' that create fluctuations in the stress field which exhibit an increasing correlation length as the critical large event becomes imminent. Our approach constitutes an attempt to build a more physically-based cumulative function in the spirit of but improving on the cumulative Benioff strain used in previous works documenting the phenomenon of accelerated seismicity. Using a space and time dependent visco-elastic Green function in a two-layer model of the Earth lithosphere, we compute the spatio-temporal stress fluctuations induced by every earthquake precursor and estimate, through an appropriate wavelet transform, the contribution of each event to the correlation properties of the stress field around the location of the main shock at different scales. Our physically-based definition of the cumulative stress function adding up the contribution of stress loads by all earthquakes preceding a main shock seems to be unable to reproduce an acceleration of the cumulative stress nor an increase of the stress correlation length similar to those observed previously for the cumulative Benioff strain. Either earthquakes are ``witnesses'' of large scale tectonic organization and/or the triggering Green function requires much more than just visco-elastic stress transfers.

arXiv comment21 pages + 13 figures in jpeg format

References in corpus (12)

• An Observational Test of the Critical Earthquake Concept
• Sub-critical and Super-critical Regimes in Epidemic Models of Earthquake Aftershocks
• Mainshocks are aftershocks of conditional foreshocks: How do foreshock statistical properties emerge from aftershock laws
• Diffusion of Earthquake Aftershock Epicenters, Omori's Law and Generalized Continuous-Time Random Walk Models
• Critical Ruptures
• Precursors, aftershocks, criticality and self-organized criticality
• Positive Feedback, Memory and the Predictability of Earthquakes
• Are Aftershocks of Large Californian Earthquakes Diffusing?
• Failure time and critical behaviour of fracture precursors in heterogeneous materials
• Fractal Plate Tectonics
• The critical earthquake concept applied to mine rockbursts with time-to-failure analysis
• New Evidence of Earthquake Precursory Phenomena in the 17 Jan. 1995 Kobe Earthquake, Japan

Cited by in corpus (1)

• Statistical Physics Approaches to Seismicity