|
|||||
|
|
Segmented seismicity of the M w 6.2 Baladeh earthquake sequence (Alborz Mountains, Iran) revealed from regional moment tensors |
|
| Authors: | Stefanie Donner Dirk Rößler Frank Krüger Abdolreza Ghods Manfred R Strecker |
| Institution: | 1. DFG Leibniz Center for Surface Process and Climate Studies, Universit?t Potsdam, Potsdam, Germany 2. Institut für Erd- und Umweltwissenschaften, Universit?t Potsdam, Potsdam, Germany 3. National Space Institute, Technical University of Denmark, Kongens Lyngby, Denmark 4. Department of Earth Sciences, Institute for Advanced Studies in Basic Sciences, Zanjan, Iran |
| Abstract: | The M w 6.2 Baladeh earthquake occurred on 28 May 2004 in the Alborz Mountains, northern Iran. This earthquake was the first strong shock in this intracontinental orogen for which digital regional broadband data are available. The Baladeh event provides a rare opportunity to study fault geometry and ongoing deformation processes using modern seismological methods. A joint inversion for hypocentres and a velocity model plus a surface-wave group dispersion curve analysis were used to obtain an adapted velocity model, customised for mid- and long-period waveform modelling. Based on the new velocity model, regional waveform data of the mainshock and larger aftershocks (M w ?≥3.3) were inverted for moment tensors. For the Baladeh mainshock, this included inversion for kinematic parameters. All analysed earthquakes show dominant thrust mechanisms at depths between 14 and 26 km, with NW–SE striking fault planes. The mainshock ruptured a 28° south-dipping area of 24 × 21 km along a north-easterly direction. The rupture plane of the mainshock does not coincide with the aftershock distribution, neither in map view nor with respect to depth. The considered aftershocks form two main clusters. The eastern cluster is associated with the mainshock. The western cluster does not appear to be connected with the rupture plane of the mainshock but, instead, indicates a second activated fault plane dipping at 85° towards the north. |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ | |