Spatial Pattern Analyses of Faulting and Epicenter of Seismic Events: Using Fry Method (case study in Yazd province)


Faculty of Earth Sciences, Shahid Chamran University, Ahvaz, Iran


     The most important lineament structures were mapped by visual and filtering analyses of the satellite images in the Yazd province. Fracture intensity map shows the higher density of fractures and faults in the central and north eastern parts of the area. The historical and recent century earthquakes epicenter map shows the concentration of the seismic events in the north eastern parts of the area. Spatial pattern analyses of brittle structures reveal a dominant NW-SE trend for faults and fractures distribution. Spatial pattern analysis of data points of the earthquakes epicenter was made using  Fry method. Results show a dominant NW-SE distribution of seismic events. Also results show an important similarity of spatial pattern distribution between earthquakes epicenter and faults. Results don’t show diffused pattern for earthquakes epicenter distribution but approximately reveal a main NW-SE linear pattern, therefore it can be deduced that the faults with  NW-SE directions are the most important seismic source for propagation of the elastic waves and earthquake events. Determination of dominant orientation of earthquake events in the different seismic province is the main practical aspect of this research.


اسلامی. س.، درخشانی. د.، 1393، کاربرد روش های عددی در شناسایی چشمه های لرزه ای: مطالعه موردی استان سیستان و بلوچستان، مجله زمین شناسی کاربردی پیشرفته دانشگاه شهید چمران اهواز ، شماره 14، ص 60-64 .
علیمی. م.ا، خطیب. م.م، خالدحسامی. آ، هیهات. م.ر، 1393، ارزیابی لرزه زمین ساختی راندگی ها و پهنه های گسلی پنهان در گستره مختاران-خاور ایران، مجله زمین شناسی کاربردی پیشرفته دانشگاه شهید چمران اهواز، شماره 12، ص 41-52 .
Austermann, J. and Iaffaldano, G., 2013. The role of the Zagros orogeny in slowing down Arabia-Eurasia convergence since ~5 Ma. Tectonics, vol. 32, pp.351-363.
Berberian, M., 1976- Contribution of the seismotectonics of Iran (Part II). Geol. Surv. Iran, Rep. No. 39.
Bhattacharya, A.R., Webber, K., 2004. Fabric development during shear deformation in the Main Central Thrust Zone, NW-Himalaya, India. Tectonophysics 387, 23–46.
Donovan, N.C., 1973. A statistical evaluation of strong motion data including the February 9. 1971. San Fernando Earthquake. Proc. 5th World Conf. Earthquake Eng.. Rome. Paper 155.
Fry, N., 1979. Random point distribution and strain measurements in rocks. Tectonophysics 60, 89e105.
Jackson, J., 1995. The accommodation of Arabia-Eurasia plate convergence in Iran. Journal of Geophysical Research, 100, 15205-15219.
Kargaranbafghi, F., Neubauer, F., Genser, J., 2011. Cenozoic kinematic evolution of southwestern Central Iran: Strain partitioning and accommodation of Arabia–Eurasia convergence. Tectonothysics, 502, 221-243.
Lacombe, O., Mouthereau, F, 2006. Late Cenozoic and modern stress fields in the western Fars (Iran): Implications for the tectonic and kinematic evolution of central Zagros. Tectonics, vol, 25, pp, 1-27
Mohajer-Ashjai. A. and Nowroozi, A.A., 1978. Observed and probability intensity zoning of Iran. Tectonophysics, 49: 21-30. Mohajer-Ashjai, A. and Nowroozi.
Nowroozi, A., 1976- Seismotectonic Provinces of Iran, Bull. Seism. Soc. Am.66, pp1249-1276.
Talebian, M. & Jackson, J., 2004. A reappraisal of earthquake focal mechanisms and active shortening in the Zagros mountains of Iran, Geophys. J. Int., 156, 506–526.
Verncombe, J, 1999. The Spatial Distribution of Mineralization: Applications of Fry Analysis. Economic Geology, vol.94, pp.475-486
Xypolias, P., 2009. Some new aspects of kinematic vorticity analysis in naturally deformed quartzites. Journal of Structural Geology 31, 3-10.