Time-dependent analysis of aftershock events and structural impacts on intraplate crustal seismicity of the Van earthquake (Mw 7.1, 23 October 2011), E-Anatolia

Toker M.

CENTRAL EUROPEAN JOURNAL OF GEOSCIENCES, vol.5, no.3, pp.423-434, 2013 (Peer-Reviewed Journal) identifier identifier

  • Publication Type: Article / Article
  • Volume: 5 Issue: 3
  • Publication Date: 2013
  • Doi Number: 10.2478/s13533-012-0141-8
  • Journal Indexes: Science Citation Index Expanded, Scopus
  • Page Numbers: pp.423-434
  • Keywords: the van earthquake, intraplate, aftershock seismicity, multifractal behavior, strain softening, EASTERN TURKEY, SLIP


The Van earthquake (M (W) 7.1, 23 October 2011) in E-Anatolia is typical representative of intraplate earthquakes. Its thrust focal character and aftershock seismicity pattern indicate the most prominent type of compound earthquakes due to its multifractal dynamic complexity and uneven compressional nature, ever seen all over Turkey. Seismicity pattern of aftershocks appears to be invariably complex in its overall characteristics of aligned clustering events. The population and distribution of the aftershock events clearly exhibit spatial variability, clustering-declustering and intermittency, consistent with multifractal scaling. The sequential growth of events during time scale shows multifractal behavior of seismicity in the focal zone. The results indicate that the extensive heterogeneity and time-dependent strength are considered to generate distinct aftershock events. These factors have structural impacts on intraplate seismicity, suggesting multifractal and unstable nature of the Van event. Multifractal seismicity is controlled by complex evolution of crustal-scale faulting, mechanical heterogeneity and seismic deformation anisotropy. Overall seismicity pattern of aftershocks provides the mechanism for strain softening process to explain the principal thrusting event in the Van earthquake. Strain localization with fault weakening controls the seismic characterization of Van earthquake and contributes to explain the anomalous occurrence of aftershocks and intraplate nature of the Van earthquake.