Temporal variations in the fractal properties of seismicity in the North Anatolian Fault Zone between 31 degrees E and 41 degrees E


Oncel A., Main I., Alptekin O., Cowie P.

PURE AND APPLIED GEOPHYSICS, vol.147, no.1, pp.147-159, 1996 (Peer-Reviewed Journal) identifier identifier

  • Publication Type: Article / Article
  • Volume: 147 Issue: 1
  • Publication Date: 1996
  • Doi Number: 10.1007/bf00876441
  • Journal Name: PURE AND APPLIED GEOPHYSICS
  • Journal Indexes: Science Citation Index Expanded, Scopus
  • Page Numbers: pp.147-159

Abstract

We investigate the nature of temporal variations in the statistical properties of seismicity associated with the North Anatolian Fault Zone between longitudes 31 degrees-41 degrees E during the instrumental period 1900-1992. Temporal variations in the seismic b value and the fractal (correlation) dimension D-c of earthquake epicenters are examined for earthquakes of magnitude M(S) greater than or equal to 4.5, using sliding windows of 100 consecutive events. b varies temporally between 0.6 and 1.0, and D-c 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 D-c, consistent with previous observation of seismicity in Japan and southern California. Major events early in this century (M(S) greater than or equal to 7) are associated with low b and high D-c, respectively consistent with greater stress intensity and greater spatial clustering of epicenters-both implying a greater degree of stress concentration at this time.