Document Type : Original Research Paper

Authors

1 earth sience , sience , Azad , shiraz , Iran

2 Department of Earth Sciences, Collage of Sciences, Shiraz University, Shiraz, Iran

Abstract

The Iranian plateau is one of the active tectonic regions on the earth. Non-uniformly distribution of deformation and repetitive activity of faults have cause a complex pattern of tectonic and seismotectonic activity of Iran. Therefore, in order to study the seismic and geological behaviors of different parts of the country one has to perform tectonic and seismotectonic zoning. Tectonic and seismotectonic zoning of Iran began by conventional methods in the past and developed by numerical zoning in recent years. Conventional methods aren't capable for producing detailed zoning maps. Recently numerical data and statistical and mathematical models have used for produce modern numerical maps. The advantage of numerical pattern recognition is that this method is a powerful tool for objective interpretation of massive of data. Multivariate statistical methods not only apply for tectonic zoning, but also this is useful to reveal the degree of significance and relationship between effective variables on tectonic zoning. In this paper, a large numbers of up-to-date geophysical, seismological, geological and geomorphological data have analyzed by using multivariate statistical methods to produced self-organized numerical tectonic and seismotectonic zoning of Iran. Based on this techniques a seven zoning tectonic and seismotectonic map has constructed for Iran. The role and significance of various parameters have also investigated using ANOVA method. The results indicate that some of the parameters play more important role in self-organized zoning. Based on relationships between parameters, they are been classified into 12 groups. Variables in each group present maximum correlation with each other. It is interesting to note that despite the frequent application of a- and b- values of the Gutenberg Richter magnitude frequency formula, these values show poor correlation with others and do not play a significant role in zoning.

Keywords

References
Allen, C. R., Amand, P. S. T., Richter, C. F. & Nordquist, J. M., 1965- Relationship between seismicity and geologic structure in the southern California region. Bulletin of the Seismological Society of America. 55(4): 753-797.
Ambraseys, N. N. & Melville, C. P., 1982- A history of Persian Earthquakees. Cambridge, University Press Cambridge, England, 219pp.
Bender, B., 1983- Maximum likelihood estimation of b values for magnitude grouped data. Bulletin of the Seismological Society America, 73(3):  831-851.
Berberian, M. & Yeat, R. S., 1999- Pattern of Historical Earthquake Rupture in the Iranian plateau. Bulletin of the Seismological Society America, 89(1):  120-139.
Boulin, J., 1991- Structures in southwest Asia and evolution of the eastern Tethys. Tectonophysics, 196: 211-268.
Choubert, G. & Faure-Muret A.M., 1980- Geological World  Atlas, 1/10,000,000 Sheets 9, 10 and 11. Commission for the Geological Map of the World, UNESCO, Paris.
Davis, J. C., Wiley, J. & Inc, S., 1973- Statistics and data analysis Geology. Translate H. memarian., M. sedaghat., k. Tafogh. 265P.
Dehghani, G. A. & Makris, J., 1981- The Gravity Field and Crustal Structural of  Iran. Institut fur Geophysik, Hamburg.
Giri, N. C. Translate: Bozorg Nia, A., 1987- Multivariate statistical inference. Astan Ghods. Publis.399P.
Gordon, A. D., 1999- Classification. Chapman and Hall, London, 417p.
Gutenberg, B. & Richter, C.F., 1954- Seismicity of the Earth and its Associate Phenomena. Princeton University Press, Princeton, NJ, 310p.
ISC., 2007- International Seismological Center, Edinburgh, Scotland, Earthquake Bulletins.
Jackson, J. A. & Mckenzie, D. P., 1984- Active tectonics of the Alpine- Himalayan Belt between Western Turkey and Pakistan. Geophysical Journal of the Royal Astronomical Society 77: 185-264.
Kalantari, Kh., 2003- Data processing and Analysis in Socia – Economic Research. Sharif Spec.Publ.388P.
Karakaisis, G. F., 1994- Long- term earthquake prediction in Iran based on the time- and magnitude- predictable model.
Kulhanek, O., 2005- Seminar on b-value. Dept. of Geophysics, Charles University.
Kulhanek, O., 2005- Seminar on b-value. Dept. of Geophysics, Charles University, Prague.
Mardia, K. V., Kent, J. T. & Bibby, J. M., 1979- Multivariate Analysis. London. New. York. Academic Press.521P.
National atlas of thematic geological & exploration maps, Geological Survey of Iran, Ministry of Industries and Mines., 2004.
NEIC., 2007- National Earthquake Information Center. Golden. Co.USA.
Nowroozi, A. A., 1976- Seismotectonic provinces of Iran. Bulletin of the Seismological Society of America 66, 1249-1276
Nowroozi, A. A., 1979- Reply to M. Berberian: comparision between instrumwntal and macroseismic epicenters. Bulletin of the Seismological Society of America 69: 641-649.
Rencher, C. & Scott, T., 1990- Assessing the contribution of individual variables following rejection of a multivariate hypothesis. 19(2): 535-553.
Richard, A. Janson & Dea, W. Wichern, 1992- Applied multivariate statistical analysis.740P.
Robert Engdahl, E., Jackson, A., Myers, C., Bergman, A. & Priestley, K., 2006- Relocation and assessment of seismicity in the Iran region. Geophys. J. Int., 167: 761-778.
 Shoja-Taheri, J. & Niazi, M., 1981- Seismicity of the Iranian plateau and bordering regions. Bulletin of the Seismological Society America, 71(2): 477-489.
Stahl, A. F., 1911- Zur geologie von Persien. In: Hunduch der Regionalen Geologie, Band, Heft 8, Heidelberg, Germany, 46p.
Stocklin, J., 1966- Tectonic of Iran (in Russian). In: Geotektonika, vol. 1, USSR Academy of science, Mosc.21   
Stocklin, J., 1968- Structural history and tectonics of Iran; a review,     American Association of petroleum Geologists Bull.,52(7): 1229-1258.       
Stocklin, J., 1977- Structural correlation of the Alpine ranges between Iran and Central Asia. Mem. H. ser. Soc. Geol. France., 8: 333-353. 
Takin, M., 1972- Iranian geology and continental drift in the Middle East. Nature 235: 147-150.
USGS, United States Geological Survey. 2007.
Zamani, A. & Hashemi, N., 2000- A comparison between seismicity, topographic relief, and gravity anomalies of the Iranian Plateau. Tectonophysics, 327: 25-36.
Zamani, A. & Hashemi, N., 2004- Computer - based self - organized tectonic zoning: a tentative pattern recognition for Iran, Computer & Geosciences, 30: 705-718. 
Zamani, A. & Agh-Atabai., M., 2009- Multifractal analysis of the spatial distribution of earthquake epicenters in the Zagros and Alborz-Kopeh Dagh Regions of Iran, in preparation.
Zamani, A. & Khajavi, N. & Tohidi, M., 2006- Study of earthquake activity in the Alpine – Himalaian orogenic belt with emphasis on the scismicity of  Iran, 6th International Conf. on the Geology of the M.East, U.A.E.