We investigate the nature of temporal variations in the statistical properties of seismicity associated with the North Anatolian Fault Zone between longitudes 31°-41°E during the instrumental period 1900-1992. Temporal vanations in the seismic b value and the fractal (correlation) dimension Dc of earthquake epicenters are examined for earthquakes of magnitude Ms ≥ 4.5, using sliding windows of 100 consecutive events, b varies temporally between 0.6 and 1.0, and Dc between 0.6 and 1.4, both representing significant fluctuations above the errors in measurement technique. A strong negative correlation (r = -0.85) is observed between b and Dc, consistent with previous observation of seismicity in Japan and southern California. Major events early in this century (MS ≥ 7) are associated with low b and high Dc, respectively consistent with greater stress intensity and greater spatial clustering of epicenters - both implying a greater degree of stress concentration at this time.
|Journal||Pure and Applied Geophysics|
|Publication status||Published - 1 Dec 1996|
- Fractal dimension
- North anatolian fault zone