Pattern recognition of the spatial distribution of earthquake epicenters in the Zagros region (Iran)

نوع مقاله : مقاله پژوهشی‌

نویسنده

Assistant Professor, School of Earth Sciences, Damghan University, Damghan, Iran

چکیده

The Zagros fold-thrust belt of Iran, as a continental-continental collision zone, is one of the most seismically active regions of the world. In this research, statistical point pattern analysis of
earthquake locations in this region during 1976-2019 and the assessment of spatial association
between earthquakes and major active faults of the region were carried out. For this purpose, different measures, (e.g., Nearest Neighbor Ratio, Global Moran’s I and Local Getis-Ord’s Gi* indices) were estimated and computed for the data catalog. Additionally, the directional anisotropy of the
earthquake epicenters distribution and earthquake-fault association were assessed. Results obtained indicate a completely clustered pattern of epicenters for the whole region and also indicate that
earthquakes with greater magnitudes show higher degrees of clustering. Also, a spatial
autocorrelation of higher values of magnitudes are observed. The spatial relationships of earthquake locations and active faults pattern indicates that the trend of maximum dispersion of epicenters for the whole region is remarkably parallel with the general trend of this belt, as well as with the
dominant trend of the major active faults of the region. Moreover, toward the south of the region, an obvious change in the directional anisotropy of epicenters is observed. The results of this study
indicate that spatial analysis techniques reliably could be employed for revealing the seismicity
pattern in tectonically active regions.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Pattern recognition of the spatial distribution of earthquake epicenters in the Zagros region (Iran)

نویسنده [English]

  • Seyed Naser Hashemi
Assistant Professor, School of Earth Sciences, Damghan University, Damghan, Iran
چکیده [English]

The Zagros fold-thrust belt of Iran, as a continental-continental collision zone, is one of the most seismically active regions of the world. In this research, statistical point pattern analysis of
earthquake locations in this region during 1976-2019 and the assessment of spatial association
between earthquakes and major active faults of the region were carried out. For this purpose, different measures, (e.g., Nearest Neighbor Ratio, Global Moran’s I and Local Getis-Ord’s Gi* indices) were estimated and computed for the data catalog. Additionally, the directional anisotropy of the
earthquake epicenters distribution and earthquake-fault association were assessed. Results obtained indicate a completely clustered pattern of epicenters for the whole region and also indicate that
earthquakes with greater magnitudes show higher degrees of clustering. Also, a spatial
autocorrelation of higher values of magnitudes are observed. The spatial relationships of earthquake locations and active faults pattern indicates that the trend of maximum dispersion of epicenters for the whole region is remarkably parallel with the general trend of this belt, as well as with the
dominant trend of the major active faults of the region. Moreover, toward the south of the region, an obvious change in the directional anisotropy of epicenters is observed. The results of this study
indicate that spatial analysis techniques reliably could be employed for revealing the seismicity
pattern in tectonically active regions.

کلیدواژه‌ها [English]

  • Point pattern statistics
  • autocorrelation indices
  • seismicity
  • spatial statistics
  • seismotectonics
  • earthquake distribution
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