{"id":549,"date":"2010-12-11T10:56:10","date_gmt":"2010-12-11T10:56:10","guid":{"rendered":"http:\/\/www.iiees.ac.ir\/en\/?p=549"},"modified":"2010-12-11T10:56:10","modified_gmt":"2010-12-11T10:56:10","slug":"report-of-surface-faulting-and-morphotectonics-of-avaj-region-earthquake-on-june-22-2002","status":"publish","type":"post","link":"http:\/\/old.iiees.ac.ir\/en\/report-of-surface-faulting-and-morphotectonics-of-avaj-region-earthquake-on-june-22-2002\/","title":{"rendered":"Report of Surface Faulting and Morphotectonics of \u201cAvaj Region\u201d Earthquake on June 22, 2002"},"content":{"rendered":"
Report of Surface Faulting and Morphotectonics of
“Avaj Region” Earthquake on June 22, 2002<\/strong><\/div>\n

\u00a0<\/p>\n

Solaymani Shahryar (Seismotectonic Group member of IIEES)
Feghhi KhalilAllah (Seismotectonic Group member of IIEES)<\/div>\n

The “Avaj Region” earthquake (48\u00ba.93 E Longitude and 35\u00ba.69 Latitude) occurred in western Iran, about 220 km West of Tehran on June 22, 2002. The moderate moment magnitude of 6.5 (USGS, 2002) [1] was calculated for this earthquake and the depth of focus was about 5-10 Km . The Fault plane Solution (USGS, 2002) indicates that the seismic event was occurred on a reverse fault having trend about N115\u00ba(Figure 1).<\/p>\n

\"Ph1\"<\/p>\n

Fig. (1): The Focal mechanism of Avaj Region earthquake (June 22, 2002). (USGS, 2002)<\/p>\n

Extensive field investigations were undertaken by The IIEES seismotectonic group during the summer 2002 (June 30 to August 27). Results of this group’s investigation during the first days after the event is presented as follows. It should be considered that, these results were not presentable before publishing [2] (because of the \u0650Copyright of authors).
Based on Active tectonic and seismotectonic studies, the causative fault of this earthquake (which has been accompanied by visible Surface faulting) has located at distance more than 8 km north of Avaj Fault. Before presenting of the research team’s results [2,3] most of the other researchers had presented several faults (Such as Avaj Fault and … .) as the causative Fault of Avaj earthquake )for example: Javan doluie et al. 2003, Zare 2003 and … ). However, based on the present study, it becomes clear that Avaj and other known faults (figures 2) were not causative fault of the earthquake. In addition, the coordinations of the earthquake epicenter (which have been reported by numerous seismological sites) do not coincide with the location of these faults.<\/p>\n

\"Ph2\"<\/p>\n

Fig. (2): The location of previous known faults of the area on the Base map [2].<\/p>\n

So, in the next step, emphasising the location of most damaged villages and studing of aerial photos of the area, we found two fault trends that had not been presented in previous Geological and Seismotectonical maps. One of them is located along the strike of Abdareh and Hossein Abad completely damaged villages, and the other one along to the strike of Changureh and Didar, damaged villages. On the aerial photos the azimuth of these two fault trends are N110\u00ba -120\u00ba (similar to the trends of epicenteral planes in Focal mechanisms) (Figure 3).<\/p>\n

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\"Ph3_s\"<\/a><\/div>\n
Fig. (3): A part of the aerial photo of studied area [2]. The visible fault trends of<\/div>\n

“Abdareh-Hossein Abad” and eastern part of “Changureh-Didar” can be seen.<\/p>\n

At the beginning of third step we found the surface faulting evidences of Avaj Region earthquake on the “Abdareh-Hossein Abad” fault trend at the eastern side of the Abdareh village (Figures 4 and 5).<\/p>\n

\"Ph4_s\"<\/a><\/p>\n

Fig. (4): Surface faulting of the Avaj earthquake at the east of Abdareh village (looking south). Date of Photography: July 16, 2002.<\/p>\n

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\"Ph5\"<\/div>\n
Fig. (5): Close up view to the Surface faulting of Avaj earthquake at distance about 200 meters east<\/div>\n

of Abdareh village (looking east). Date of Photography: July 17, 2002.<\/p>\n

The investigations and measurements on the plane of the earthquake fault (through the east and west of Abdareh village) indicated the following results [2 and 3]:<\/p>\n