The 18 august 2014 Mw 6.2 Mormori, Iran, earthquake: a thin'skinned faulting in the Zagros mountain inferred from InSAR measurement

• Autores: Mahdi Motagh, Abbas Bahroudi, Mahmud Haghshenas Haghighi, Sergey Samsonov
• Localización: Seismological Research Letters, ISSN 0895-0695, ISSN-e 1938-2057, Vol. 86, Nº. 3, 2015, págs. 775-782
• Idioma: inglés
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• Resumen

  • Online Material: Figures of interferograms, posteriori probability distribution of fault parameters, tradeoff curve, checkerboard test and modeling results for entire area, and tables of boundaries used in the inversion and of digital slip distribution.

    Studies of fault geometry and slip distribution associated with large earthquakes are important to improve our understanding of how continental lithosphere behaves physically in response to plate tectonic motions. The Zagros mountain fold-and-thrust belt in southwestern Iran is one of the largest and most active belts on our planet with continuous seismicity. This northwest-southeast-trending belt extends in southwestern Iran within the Alpine-Himalayan orogenic chain, accommodating approximately 10??mm/yr of north-south shortening between Arabia and Eurasia (Nilforoushan et al., 2003; Tatar et al., 2004; Vernant et al., 2004). Earthquakes with moderate magnitudes of 5.5-6 mb are common in the ~250-350km wide zone along the Zagros fold-and-thrust belt (Jackson, 1980a; Berberian, 1995). Although, most of these earthquakes within the belt are not accurately located by teleseismic data (Jackson and Fitch, 1981; Ni and Barazangi, 1986), studies suggest that the seismicity has been restricted to a depth of less than 40 km (Maggi et al., 2000).

    Much work has been done in the past to improve our understanding of the shortening mechanism in the Zagros (Koyi et al., 2000; Tatar et al., 2004; Yamini-Fard et al., 2007; Authemayou et al., 2009; Oveisi et al., 2009). Both thick-skinned deformation (Jackson, 1980b; Berberian, 1995) and thin-skinned deformation (Hessami et al., 2006; Walpersdorf et al., 2006) models have been proposed for geodynamic evolution of Zagros orogeny; in the former model, the shortening is accommodated by reverse basement faulting that is separated from shallow sedimentary rocks by the infra-Cambrian Hormuz salt sequence, and, in the latter model, active folding of the shallow sediments...