QUANTITATIVE ANALYSIS OF THE SPATIAL DISTRIBUTION OF THE EARTHQUAKE EPICENTERS IN IRAN DURING 2001-2010

This study presents a two-dimensional GIS-based spatial analysis of the well-located earthquake epicenters of the Iranian plateau in order to reveal the characteristics of the distribution patterns as well as to interpret the relationships between these distribution patterns and the geologicalstructures in different parts of the region. It is expected that the study of the spatial pattern of the distribution of earthquake epicenters would be useful for revealing the underlying processes that generated these earthquakes. In this research, earthquake data of the Iranian plateau (with magnitude 3.5 and greater) during 2001-2010, were extracted from different catalogs and analyzed. For this purpose, the ArcGis package (version 9.3) was employed. The entire dataset of epicenters of the region shows a distinct statistical clustering. The degree of clustering and directional distribution of epicenters, were estimated for different parts of the region. Results obtained reveal that the spatial patterns of the epicenters distribution, especially in Alborz and Zagros zones, are meaningfully controlled by the trends and mechanisms of the major faults and folds in these regions. Additionally, it has been observed that the orientations of the major axes of the directional distribution of earthquakes are more or less parallel with the trends of these major active faults and folds. As a result, it is concluded that these structural features play an important role in controlling the occurrences of earthquakes in these regions

کلیدواژه ها:

Point Pattern Analysis ، Seismicity ، Geostatistics ، Spatial Analysis ، Iran