American Geophysical Union, California, Amerika Birleşik Devletleri, 9 - 13 Aralık 2019, ss.1
The aim of this study is to investigate qualitative and quantitative temporal and spatial behavior of creep along the eastern section of the Eastern Anatolian Fault (EAF), forming the boundary between the Anatolian and Arabian plates in Turkey. We determined aseismic creep for the 100 km-long Palu Segment in the Elazıg- Bingöl seismic gap (seismologists assumed that expected Magnitude is >7) by using creepmeters, InSAR, GNSS and seismic observations in 2014. The surface creep rate varies along the fault locally attaining the far-field plate velocity (≈10 mm/yr), which simply suggests that a significant portion of the elastic strain is being released aseismically. However, this situation will cause a large amount of stress changes at the tips of the creeping segments and the earthquake potential on the neighboring fault segments particularly at shallow depths will be higher.
Therefore, we started a new multidisciplinary (geodetic, geophysical, geological) studies in order not only to document the spatial distribution of this creep motion but also to have a better understanding of its spatio-temporal behavior for the seismic hazard assessment of the region in 2019. In this period, we started to monitor the deformations by using Terrestrial Laser Scanner (TLS) in the Palu railway tunnel, crossing the fault where the walls of the tunnel have been offset by 10-20 cm since the construction in the middle of the last century. The first results showed that the TLS technique gives promising results for surficial deformation monitoring for the Palu railway tunnel. Hence, while TLS data can give spatial information, creepmeters can give point-based measurements in the tunnel. Moreover, fault rocks have been sampled for mineralogical and geochemical analyses in order to understand the linkage between the lithology and creeping in this particular section of the EAF.
The outcomes of our multidisciplinary study will be used for more reliable seismic hazard assessments for the region and will allow a better understanding of the behavior of the EAF and creep phenomena in general for the scientific community. (This study is supported by TUBITAK projects 114Y250 and 118Y450).
Keywords: Hazar-Palu, Creep, East Anatolian Fault, Earthquake, InSAR, GNSS, TLS