Space-time correlations of seismotectonic parameters: Examples from Japan and from Turkey preceding the Izmit earthquake

Abstract

Analysis of the correlation between fractal attributes of complex seismotectonic variables may offer insights into seismic hazard assessment. The Gutenberg-Richter, moment-magnitude, and moment-source area relations yield a direct fractal relationship among the Gutenberg-Richter b-value, occurrence rate, and the characteristic linear dimension of the fault plane (square root of fault surface area). In contrast, temporal variation in the correlation dimension of epicenters (D-C) is found, in several studies, to correlate negatively with the b-value in different regions of the world. Spatial variations between the b-value and D-C also tend to oppose each other. In Japan, negative correlations are also observed in the regional scale comparisons of the capacity dimension (D-o) of active fault systems and the b-value. However, at local scales, the relationship yields both positive and negative correlation. The occurrence of positive or negative correlation appears to be controlled by different modes of failure within the active fault complex.