Determination of periodic deformation from InSAR results using the FFT time series analysis method in Gediz Graben

Permanent Scatterers (PS) point velocities obtained by the interferometric synthetic aperture radar (InSAR) method are generally determined using the linear regression model, which ignores periodic and seasonal effects. In this study, software was developed that can detect periodic effects by applying fast Fourier transformation (FFT) time series analysis to InSAR results. Using the FFT time series analysis, the periodic components of the surface movements at the PS points were determined, and then the annual velocity values free from periodic effects were obtained. The study area was chosen as the Gediz Graben, a tectonically active region where aseismic surface deformations have been observed in recent years. As a result, using the developed method, seasonal effects were successfully determined with the InSAR method at the PS points in the study area with a period of 384 days and an average amplitude of 19 mm. In addition, groundwater level changes of a water well in the region were modeled, and 0.93 correlation coefficient values were calculated between seasonal InSAR displacement values and water level changes. Thus, using the developed methodology, the relationship between the tectonic movement in the Gediz Graben in Turkey and the seasonal movements and the change in the groundwater level was determined

Cl-36 exposure dating of paleoearthquakes in the Eastern Mediterranean: First results from the western Anatolian Extensional Province, Manisa fault zone, Turkey

Based on historical and instrumental data, societies in the Eastern Mediterranean and Middle East have survived at least 150 large earthquakes (generally M > 6) during the past 2500 yr. Beyond this time span, an earthquake chronology is mostly unknown, which hampers the production of reliable long-term earthquake models. Since the only remaining evidence of seismic activity is a bedrock scarp, cosmogenic Cl-36 is the only suitable nuclide to be applied in the determination of the seismic history and slip rate of an active limestone fault plane. In this study, we focus on the 4-m-high Mugirtepe fault scarp within the active Manisa fault zone in western Anatolia, one of the most seismically active and rapidly extending regions in the world. We analyzed 44 samples in two slightly overlapping strips, which in total covered 2.65 m of the fault scarp. In order to determine the timing and the amount of slip of the paleoseismic events, we analyzed the measured Cl-36 concentrations using the Schlagenhauf Matlab (R) code. We used two different scenarios based on two different inherited Cl-36 concentrations as constrained by our data and modeling. The best fit for the first scenario yields two seismic events, one at 13.7 +/- 0.8 ka with a displacement of 0.5 +/- 0.2 m and one at 7.8 +/- 0.5 ka with 2.15 +/- 0.35 m offset. For the second scenario, we obtained a single seismic event at 8.6 +/- 0.6 ka with 2.65 +/- 0.35 m of slip. These results indicate that the visible part of the Mugirtepe exposed fault scarp had achieved most of its displacement already by 8 ka. Initial surface faulting at Mugirtepe occurred not later than around 14 ka, and marked seismic activity continued until around 8 ka. Our first results from the western Anatolian Extensional Province show the ability to reveal periods of enhanced seismic activity beyond historical data using cosmogenic Cl-36

The Evaluation of Damage Mechanism of Unreinforced Masonry Buildings After Van (2011) and Elazig (2010) Earthquakes

On March 8th, 2010 Karakocan-Elazig earthquake of magnitude 6.0 occurred at a region where masonry and adobe construction is very common Karakocan-Elazig is located in a high seismicity region on Eastern Anatolian Fault System (EAFS). Due to the earthquake, 42 people were killed and 14'113 buildings were damaged. Another city, Van located at South east of Turkey is hit by earthquakes with M = 7.2 occurred on October 23rd, 2011 at 13:41 (local time), whose epicenter was about 16 km north of Van (Tabanli village) and M = 5.6 on November 9th, 2011 with an epicenter near the town of Edremit, south of Van and caused the loss of life and heavy damages. Both earthquakes killed 644 people and 2608 people were injured. Approximately 10'000 buildings were seriously damaged. There are many traditional types of structures existing in the region hit by earthquakes (both Van and Elazig). These buildings were built as adobe, unreinforced masonry or mixed type. These types of buildings are very common in rural areas (especially south and east) of Turkey because of easy workmanship and cheap construction cost. Many of those traditional type structures experienced serious damages. The use of masonry is very common in some of the world's most hazard-prone regions, such as in Latin America, Africa, the Indian subcontinent and other parts of Asia, the Middle East, and southern Europe. Based on damage and failure mechanism of those buildings, the parameters affecting the seismic performance of those traditional buildings are analyzed in this paper. The foundation type, soil conditions, production method of the masonry blocks, construction method, the geometry of the masonry walls, workmanship quality, existence of wooden beams, type of roof, mortar between adobe blocks are studied in order to understand the reason of damage for these types of buildings.WoSScopu