Abstract
Two earthquakes occurred on 11 August 2012 in East Azerbaijan province, NW Iran with Mw 6.3 at 12:23:15.9 and Mw 6.1; 11 minutes after the first shock at 12:34:34.8 GMT time. In this study, we concentrated on the properties of the aftershock sequences in a duration of 7.5-month time-period data after the main shocks, recorded by Broadband Iranian Network (BIN). We obtained p, c and K parameters with the maximum likelihood method and the occurrence rate was modeled by the modified Omori formula. Besides, we showed that aftershocks of the aftershock in 7 Nov. 2012 (M = 5.6) also decay according to the modified Omori law. We investigated the spatial and temporal variations of b-values before and after the twin earthquakes with Mw 6.3 and Mw 6.1 approximately 20 km around North Tabriz Fault (NTF) in the region from 1996 to 2013 using Iranian Seismological Center (IRSC). We believed that a research of the past 17 years has clearly established that spatial b-value changes and seismicity rate are highly significant and meaningful. Moreover, our research led to a warning for a probable strong motion along NTF for the coming couple of years.
Highlights
Situated in the north west of Iran, Tabriz has been severely damaged by several historical strong events in the past
We concentrated on the properties of the aftershock sequences in a duration of 7.5-month time-period data after the main shocks, recorded by Broadband Iranian Network (BIN)
We investigated the spatial and temporal variations of b-values before and after the twin earthquakes with Mw 6.3 and Mw 6.1 approximately 20 km around North Tabriz Fault (NTF) in the region from 1996 to 2013 using Iranian Seismological Center (IRSC)
Summary
Situated in the north west of Iran, Tabriz has been severely damaged by several historical strong events in the past. Seismic events often have aftershocks that may cause a second hazard for buildings. Beside this fact, aftershocks data have useful information about stress changes and source properties of the mainshocks by checking several parameters such as b-value estimations, decay rate of aftershocks with time, and seismicity rate. There are some relations that express aftershocks activity such as the Gutenberg-Richter’s and the modified Omori’s laws. These laws describe the size distribution of earthquakes and the decay rate of the aftershock activity, respectively [2]. B-value usually varies between 0.6 and 1.0 It is >1 for regions with abundant earthquake swarms. We assessed statistical properties of aftershock sequences and investigated seismicity of North Tabriz Fault
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
