Seismotectonic investigation of the Central Kopeh Dagh range using Seismicity parameters and fractal dimension by specific attention to Bakharden–Quchan fault zone

Document Type : Original Article

Authors

1 1MSc, Seismic Network of Mashhad, Institute of Geophysics, University of Tehran, Iran

2 Department of Geology, Ferdowsi University of Mashhad, Iran

3 Associate professor, Earth Physics Department, Institute of Geophysics, University of Tehran, Iran

Abstract

 
In this research, using data from earthquakes recorded in Central Kopeh Dagh range, by the Iranian Seismological Center  (http://irsc.ut.ac.ir), we have interpreted Tectonic of the range by calculating seismicity parameters a-value, b-value and fractal dimension. Kopeh Dagh range, is northern zone of deformation caused by the convergence of the Arabian and Eurasian plates. It forms an active tectonic zone trending northwest - southeast, on the border between Turan platform to the North and Lut-Central Iran Blocks to the south.
The Map of  b-value, shows that this parameter changes between about 0.6 to 1.1, that is usually seen in tectonically active areas. The fractal dimension of region is 1.75 that expresses the complex and multiple stresses on the range. Maps of  b- value and fractal dimension of earthquake epicenters, shows a clear change in the Bakharden–Quchan fault zone, so that it can be divided into three distinct parts. Parts A and C forms the asperities and part B is located between them. The results show that using the seismicity parameters a-value and b-value, fractal dimension and  local stress distribution maps, provide valuable information about the mechanism of faults and fault systems changes over time.

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References

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Journal of Tectonics
Volume 1, April2015
April 2015
Pages 78-90

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