Morphometric Measurement of the Faults in Kerman Province and Its Relation with Earthquake Magnitude in Richter Scale
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International Journal of Advanced Biotechnology and Research (IJBR) ISSN 0976-2612, Online ISSN 2278–599X, Vol-7, Special Issue3-April, 2016, pp560-569 http://www.bipublication.com Research Article Morphometric measurement of the faults in Kerman province and its relation with earthquake magnitude in Richter scale Mostafa khabazi1*, Mohammad Javad Nazari2, S.Ali Almodaresi3 and Amir Hosin Abotalb4 1*Assistant professor, Department of Geography, Faculty of literature, Shahid Bahonar University of Kerman, Kerman, Iran [email protected] 1M.A student, Department of Surveying Engineering, Faculty of Engineering, Larestan Branch, Islamic Azad University. 2Associate Professor, 3GIS&RS Department Yazd Branch, Islamic Azad University. 4M.A .GIS&RS Department Yazd Branch, Islamic Azad University. ABSTRACT Iran is geographically one of the most prone regions to natural disasters especially earthquake in the world such that it is in the seventh place in Asia and the 13th place in the world regarding annual mean of the highest number of population at risk of earthquake. On the other hand, 32% of the area, 70% of the population, and 67% of the gross production of the country are located in regions prone to earthquake. Iran with its several faults is always prone to this terrible natural disaster and it is one of high risk regions regarding the earthquake. There is a mutual relation between fault and earthquake. It means that the number of faults in the region is effective on earthquake occurrence. On the other hand, every earthquake will cause creation of new faults. In present research, the faults in the region will be positioned using satellite images and their dimensions have been measured by GIS advanced techniques. Then, the relationship between fault length and earthquake magnitude will be studied and the amount of human and inhuman losses of earthquake have been estimated. Therefore, the potential and allometric power of a fault such as length, width, and depth of a fault has been estimated in occurrence of earthquake. Then the extension of ruptures resulted from earthquake has been determined in the area of fault and finally the region has been zoned into non-risky, low risk and high risk categories. Results show that there is a direct relationship between fault length and its magnitude in Richter scale. The longer the length of the fault, the earthquake will be more intensive. The highest frequency of earthquake associates to the west and northwest of the region under study meaning where faults are longer and denser. Keywords: earthquake, allometry, morpho-tectonic, Kerman INTRODUCTION Faulting like earthquake has financial and in the world regarding annual mean of the physical risks for human being and if it occurs, highest number of population at risk of it will be a potential risk for vital facilities of earthquake. Iran is among those countries which human being. For this reason, having has high vulnerability against seismic risks information about possible losses of earthquake (Bargi 2000:103, Vazin, 2007, Jafari and Saeidi for being prepared for more suitable crisis 1994) such that 32% of the area, 70% of the management after earthquake occurrence is one population, and 67% of the gross production of of challenges faced by today human beings. One the country are located in regions prone to the other hand, geographically Iran is one of the earthquake (WDI, 2004). Therefore, studying most prone regions to natural disasters the length of rupture resulted from earthquake is (especially earthquake) in the world such that it the least contribution to reduction of losses after is in the seventh place in Asia and the 13th place earthquake. So by knowing the extension of fault destroyed by earthquake, urban Research background development and construction can be limited in Several researches have been done on order to minimize the losses after earthquake earthquake and morphometric effect of fault on occurrence. Also, zoning the region into low risk earthquake magnitude and some of them have and high risk ones can be effective in direction been summarized in table 1. of preventing urban development in high risk regions. Table 1: research background on the subject under study Surname Name year Research title Zaliapin Ilya 2013 Earthquake clusters in southern California Geology and stratigraphy (oligomiocene row and miopaleocene row), Conrad George 1970 Lout tectonic Motamed Ahamd 1974 Research design of Lout Mirzaei et al Nourbakhsh 2002 Basic parameters of Iranian earthquakes The role of remote measurement and field studies on morpho-tectonic Alavipanah et al Kazem 2007 analyses Azizizadeh et al Mehran 2011 Techniques of remote measurement of Izeh fault structure Rajabi Masoumeh 2013 Neo-tectonic and geo-morphological effects of the main fault of Tabriz Geographical location of the region under study Iran is located in south west of Asia and Middle East region with 1648195 Km2 areas. It extends to Caspian Sea from the north and to Persian Gulf and Oman Sea from the south. Kerman province (the widest province in Iran) is located in south east of Iran. The population of the province was 2938988 people in 2011 based on census of statistical center of Iran. Its capital is Kerman. Kerman is the largest province in Iran regarding earthy expansion (11% of Iranian expansion) and regarding the maritime boundary, it is the second widest province in Iran after Sistan & Baluchistan (Fig. No: 1). Mostafa khabazi, et al. 561 Fig.1: geographical location of the region under study Research methodology - preparing maps required for the region with appropriate scale (125000 and 150000 maps in this research) - taking satellite images from the region with appropriate scales - preparing geological maps from important faults in the region - positioning and identifying faults in satellite images by ENVI software - visiting the region and adapting fault maps with geological realities of the region - adapting faults derived from satellite images with topographic maps of the region by ArcGIS software - measuring dimensions of the faults of the region under study - preparing statistical information from earthquakes occurred in recent years in faults of the region under study - studying the amount of earthquake magnitude occurred in identified faults and also expansion of the rupture resulted from the earthquake - calculating the possible relationship between fault dimensions and earthquake magnitudes of the fault, expansion of rupture and the destruction - summarizing and analyzing results and final conclusion The main discussion The distribution and mechanism of faults in Kerman province Mostafa khabazi, et al. 562 Faults of Kerman are towards north west-south east and to some extent to north-south and they are long faults that incline towards the west. The movement of these faults is right handed strike-slip and results from Katanga orogeny in the late Precambrian. Their trends agree with seismotectonic trends related to Katanga folding. These faults usually form the border between structural-sedimentary units in the region such that they cause changes in stone faces, thickness of sediments and seismotectonic alterations such as magmatism, deformation, and folding during geological periods. The faults in this region form weak points of the crust so that energy centralized in the earth can be released from these points. Therefore, these faults are effective on seismicity of the region. In addition to main faults, small and subsidiary faults are seismic as well and they can create great earthquakes depending on the direction and type of pressures present in the earth. Therefore, regarding the placement of recent earthquake centers on these faults (main and subsidiary), most of the faults in this region are active and high risk. Concerning the studies done in this regard, most of old faults of the region have right handed movement while current active faults are left handed strike-slip depending on the pressures. In addition, the amount of displacement is not similar in the fault and it may be compressive or tensile. New movements of young faults are destroyed by erosion or vegetative coverage (buried faults). So the importance of these faults should not be ignored. However, such movements can be tracked by the signs appeared on the earth. Classification of the faults in the region under study based on density and direction By looking carefully at size & tectonic map of Kerman and studying the trend and direction of faults in macro view, The region under study can be investigated in three profiles based on fig.///. Each profile with morphometric features will be analyzed allometrically. Fig. /// profile and faults plotted on the region under study A) Profile of northwest- northeast (A-B) This profile (with the direction shown in fig.///) crosses cities and villages in north west and north east. The most important fault in this region is Kouhbanan fault with 300 kilometers long and it has extended from north of Kerman to northwest of Bahabad. This fault was firstly identified by Huckriede et al and its name was originated from the city of Kouhbanan. The fault divides into several parts in its passage (table) Fig:A-B section, overlay of fault layers on satellite images of Google earth Mostafa khabazi, et al. 563 Fig./// faults and domain of the profile A-B Table: specifications of different parts of Kouhbanan fault Name of fault Length in Km Distance from Kerman (in Km) Kouhbanan 1 27 30 Kouhbanan 2 19 56 Kouhbanan 3 30 69 Kouhbanan 4 31 92 Kouhbanan 5 9 125 Kouhbanan 6 25 135 Kouhbanan 7 54 151 Kouhbanan 8 33 14 Kouhbanan 9 85 34 Kouhbanan fault displaces clearly young sediments in some points and it is observable in Gisak village in the boundary of mountain and desert (Shahpasand Zadeh & Heidari: 1996). This fault inclines to the northeast end and continues irregularly. In eastern part of Zarand, this fault has caused thrust of Precambrian formation on younger formations towards the western end (Triassic and Jurassic).