Application of IRSL Method for Dating of the Suleghan Landslide: The 23 February 958 MS 7.1 Ray-Taleghan/Ruyan Earthquake
عنوان دوره: نوزدهمین کنفرانس ژئوفیزیک ایران
نویسندگان
1موسسه ژئوفیزیک
2موسسه ژئوفیزیک دانشگاه تهران
3دانشیار
4دانشجو
چکیده
The study of earthquakes in mountainous ranges suggests that large magnitude earthquakes have usually caused multiple landslides. The southern part of central Alborz contains many landslides. Several seismic events have occurred in this area. Without having the absolute age of each individual landslide it is not possible to attribute the landslide to specific seismic events. So, we are faced with a completely unknown seismic event that has triggered the mass movements. To evaluate the potential of luminescence dating for finding the absolute age of landslides in Alborz, we decided to initiate our work with dating two large landslides (Suleghan and Keshar-e Sofla) in the north of the Tehran megacity, which had the potential of being earthquake-induced landslides. We used Suleghan landslide dammed-lake deposits to obtain the age of seismic event employing the Infrared Stimulated Luminescence (IRSL) for feldspar grains. We obtained the age of the mass-movement event less than 1.03 ± 0.08 ka. Our result suggests that the Suleghan landslide was triggered by the 23 February 958 MS 7.1 Ray-Taleqan/Ruyan earthquake. Based on this work, careful study of landslides using OSL dating methods can lead to determining the age of other mass movements in Iran. Multiple landslides with identical age will be attributed to a seismic event. That seismic event can be a known earthquake or an unknown earthquake. Finding an unknown earthquake will complete the earthquake catalog and a better hazard assessment.
کلیدواژه ها
 
Title
Application of IRSL Method for Dating of the Suleghan Landslide: The 23 February 958 MS 7.1 Ray-Taleghan/Ruyan Earthquake
Authors
Mehdi Torabi, morteza fattahi, Hamide Amini, Mohammad Reza Ghassemi, Nasrin Karimi
Abstract
The study of earthquakes in mountainous ranges suggests that large magnitude earthquakes have usually caused multiple landslides. The southern part of central Alborz contains many landslides. Several seismic events have occurred in this area. Without having the absolute age of each individual landslide it is not possible to attribute the landslide to specific seismic events. So, we are faced with a completely unknown seismic event that has triggered the mass movements. To evaluate the potential of luminescence dating for finding the absolute age of landslides in Alborz, we decided to initiate our work with dating two large landslides (Suleghan and Keshar-e Sofla) in the north of the Tehran megacity, which had the potential of being earthquake-induced landslides. We used Suleghan landslide dammed-lake deposits to obtain the age of seismic event employing the Infrared Stimulated Luminescence (IRSL) for feldspar grains. We obtained the age of the mass-movement event less than 1.03 ± 0.08 ka. Our result suggests that the Suleghan landslide was triggered by the 23 February 958 MS 7.1 Ray-Taleqan/Ruyan earthquake. Based on this work, careful study of landslides using OSL dating methods can lead to determining the age of other mass movements in Iran. Multiple landslides with identical age will be attributed to a seismic event. That seismic event can be a known earthquake or an unknown earthquake. Finding an unknown earthquake will complete the earthquake catalog and a better hazard assessment.
Keywords
Mass movements, IRSL, Suleghan, Ruyan Earthquake