Fault rupture and stress changes associated with the November 27, 2005 Qeshm Island (Iran) earthquake (M W = 6.0)

Murat Utkucu, Serap Kizilbuğa, Hasan Arman

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

The November 27, 2005 Qeshm Island earthquake (Mw 6.0) occurred along the Zagros Thrust and Fold Belt which accommodates about half of the deformation caused by the Arabian and Eurasian Plates convergence. As typical for the belt, the earthquake was associated with buried reverse faulting and produced no surface rupture. Here, teleseismic broadband P velocity waveforms of the earthquake are inverted to obtain coseismic finite-fault slip distribution of the earthquake. It is obtained that rupture was controlled by failure of a single asperity with largest displacement of approximately 0.6 m, which occurred at a depth of 9 km. The slip model indicated radial rupture propagation from the hypocentre and confirmed blind reverse faulting within deeper part (below the depth of 6 km) of the sedimentary cover above the Hormuz Salt, lying between the cover and the basement, releasing a seismic moment of about 1.3 × 1018 Nm (MW = 6.0). The results also confirm that the Hormuz Salt behaves as a barrier for rupture propagation to the basement below and occurrence of the aftershock activity downdip from the rupture within the Hormuz Salt. Calculated Coulomb stress variations caused by the coseismic rupture indicates stress coupling between the 2005 Qeshm Island earthquake and both the largest aftershock several hours later and the 2008 Qeshm Island earthquake (MW = 5.9). The stress calculations further indicated stress load at the depth range (15–20 km) of the well-located aftershocks, corresponding to depths of the Hormuz Salt and top of the basement and providing plausible explanation for occurrence of the aftershocks within those layers.

Original languageEnglish
Article number726
JournalArabian Journal of Geosciences
Volume11
Issue number22
DOIs
Publication statusPublished - Nov 1 2018

Keywords

  • 27 November 2005 Qeshm Island earthquake
  • Finite-fault inversion
  • Seismotectonic of Iran
  • Zagros thrust and fold belt

ASJC Scopus subject areas

  • Environmental Science(all)
  • Earth and Planetary Sciences(all)

Fingerprint

Dive into the research topics of 'Fault rupture and stress changes associated with the November 27, 2005 Qeshm Island (Iran) earthquake (M W = 6.0)'. Together they form a unique fingerprint.

Cite this