Ibrahim Tiryakioglu

GPS Velocity and Strain Rate Fields in Southwest Anatolia from Repeated GPS Measurements

Southwestern Turkey is a tectonically active area. To determine kinematics and strain distribution in this region, a GPS network of sixteen stations was established. We have used GPS velocity field data for southwest Anatolia from continuous measurements covering the period 2003 to 2006 to estimate current crustal deformation of this tectonically active region. GPS data were processed using GAMIT/GLOBK software and velocity and strain rate fields were estimated in the study area. The measurements showed velocities of 15–30 mm/yr toward the southwest and strain values up to 0.28–8.23×10−8. Results showed that extension has been determined in the Burdur-Isparta region. In this study, all of strain data reveal an extensional neotectonic regime through the northeast edge of the Isparta Angle despite the previously reported compressional neotectonic regime. Meanwhile, results showed some small differences relatively with the 2006 model of Reilinger et al. As a result, active tectonic movements, in agreement with earthquake fault plane solutions showed important activity.

Geodetic aspects of the 19 May 2011 Simav earthquake in Turkey

On 19 May 2011, an earthquake of magnitude Mw:5.9 occurred just 9.1 km below the surface of the earth on the Simav fault in Turkey. The region is located north-west of the Gediz graben, one of the major tectonic structures in the extensional regime of western Anatolia. In this study, from 2009 to 2011, the data from nine Continuously Operating Reference Stations (CORS-TR) in the region and one permanent Global Navigation Satellite System station working locally were assessed and analysed using GAMIT/GLOBK software. The behaviour of these stations before and after the earthquake was analysed using calculated time series. At the same time, the strain and rotation rates of current deformation in the Simav region were computed using the 2008–2011 data from the CORS-TR network. The directions obtained from the focal mechanism solutions and strain analysis of the Simav earthquake were observed as being in harmony. Nonetheless, Simav earthquake caused a displacement of 1–2 mm (approximately) in nearby locations. The Simav earthquake shows that the extensional regime in western Anatolia has recently been active in the region and is a good example of the evolution of the graben system.

Monitoring the tectonic plate movements in Turkey based on the national continuous GNSS network

In recent decades, the space geodesy has been applied to the areas such as transportation, infrastructure planning, navigation, etc. Among them, the precise positioning at the Global Navigation Satellite System (GNSS) stations yields better view in the understanding of the crustal deformation that requires global-scale measurements. There have been numerous studies examining the data process of continuous GNSS observations in the field of earth monitoring. More recently, GNSS stations established for continuously operating reference station networks have been beneficial resources in the tectonic plate-monitoring studies in lieu of campaign-type observations. However, this requires that the Continuously Operating Reference Station (CORS) should be established on stable structures acting like foundations and requires investigation of the long-term repeatability time series. This study aims to introduce recently established national CORS network, named CORS-TR, covering the entire Turkey and Northern Cyprus, and to explain the process of the long-term data obtained from the network on the characteristics of the tectonic plate movement within the area. The results of the CORS-TR data process present a great potential of using continuously operating reference stations not only in real-time kinematic applications of conventional geodesy studies but also in detecting and monitoring the crustal deformations of those that are crucial in earthquake-prone areas like Turkey. Since the findings are computed from the results of the all permanent stations of CORS-TR network, this study also examines the GNSS observation quality of the network for the given time interval. One of the major conclusions of the data process conducted in the study displays that the CORS-TR stations established on the carefully selected large and low-rise existing building had been more stable than the stations on the ground which have been subjected to soil settlement since the construction.

Slip distribution and source parameters of the 20 July 2017 Bodrum-Kos earthquake (Mw6.6) from GPS observations

Abstract Greek-Turkish boundary near the cities Kos and Bodrum has been shaken on July 20, 2017 by a Mw6.6 earthquake. The mainshock is located offshore and did not generate an on-land surface rupture. Analyzing pre- and post-earthquake continuous/survey-type static GPS observations, we investigated co-seismic surface displacements at 20 sites to characterize source parameters and slip-distribution of the mainshock. Fault plane solutions as well as co-seismic slip distribution have been acquired through the inversion of co-seismic GPS displacements modeling the event as elastic dislocations in a half space. Fault plane solution shows a southward dipping normal-type fault segment extending a depth down to ~12 km, which remains within the brittle upper crust. Results from the distributed slip inversion show that the mainshock activated a ~65 km fault section, which has three high slip patches, namely western, central and eastern patches, where the coseismic slips reach up to 13, 26, and 5 cm, respectively. This slip pattern indicates that the pre-earthquake coupling, which is storing the slip deficit, occurred on these three patches.

Monitoring of Deformations Along Fethiye-Burdur Fault Zone (Turkey) with GPS

Afyonkarahisar, Burdur and Fethiye region, southwest of Turkey is located on a tectonically active area. According to the historical recordings, the region was destructed by earthquakes many times. Since the beginning of the 20th century, more than 35 earthquakes with magnitudes bigger than 4 occurred in Afyonkarahisar region. Seven earthquakes recorded over the last 90 years in the region between Burdur and Fethiye whose magnitudes are between 5.0 and 7.0. This new project “Monitoring of Deformations Along Fethiye-Burdur Fault Zone With GPS”, is founded by The Scientific and Technical Research Council of Turkey (TUBITAK), Istanbul Technical University (ITU), Karadeniz Technical University (KTU) and Afyon Kocatepe University (AKU). The aim of the project is to determine strain accumulation of the study area.

Monitoring the deformation and strain analysis on the Ataturk Dam, Turkey

ABSTRACT Every man-made structure creates certain risks — dams are no exception. Most failures in man-made structures that have occurred could have been avoided if the structures’ behaviour had been inspected, monitored, and analyzed continuously, and if proper corrective measures had been taken in a timely fashion. The DSI (The General Directorate of State Hydraulic Works), which is the institution responsible for dam safety, has long used surveying methods to measure the displacements of geodetic points as a part of dam monitoring policy. In this study, we focus on the dams mechanical behaviour throughout a time period of more than 10 years. These study results have been derived from a separate, ongoing project that has monitored deformation on the Ataturk Dam and is now determining the water level of the reservoir. The project results show that although the dam body has become more stable and the water load behind the dam has increased, the rate of displacement of the dam has declined significantly. From these results, it can be seen that the reservoir water level can be increased evenly over time and that 542 m is the maximum water level of the dams reservoir.

Crustal Deformation Modelling by GNSS Measurements: Southwestern Anatolia, Turkey

The Western and Southwestern Anatolia are located in a tectonically active region in Turkey (Fig. 1). Many studies have been conducted on the mechanism of fault systems of this region. Open image in new window Fig. 1 Major tectonic structures of the Southwestern Anatolia

Current Tectonic Movements Monitoring in Aksehir-Sultandagi Fault Zone After the February 2002 (Mw: 6.2) Earthquake

Aksehir-Sultandagi Fault Zone (ASFZ) is one of the most important seismogenic zones located in the expansion region of Western Anatolia.

The determination of relations between statistical seismicity data and geodetic strain analysis, and the analysis of seismic hazard in southwest Anatolia

This study aims the relations between seismicity data and strain analysis based on geodetic space techniques in order to define the seismicity hazard of the southwest Anatolian region of Turkey. This region has complex tectonic formations and requires sophisticated techniques and approaches to investigate seismic activities. In this study, global navigation satellite system (GNSS) observations were used to determine the velocity field of the region. The strain rates of the region were obtained from the evaluation of this velocity field. In addition, seismicity b parameters of the region were calculated from the analysis of seismicity data. Furthermore, the seismicity data and the geodetic strain rates obtained from the GNSS observations were combined to show the statistical correlation. This correlation was interpreted to define the seismicity. According to the results derived from the correlation analysis, the geodetic strain analysis and seismicity data were highly and inversely correlated (r = −0.96). After the determination of the correlation, the seismic hazard data of the region was added to the analysis. This process shows that seismic hazards are highly and negatively correlated to seismicity data (r = −0.90), even though they are highly but positively correlated to geodetic strain analysis (r = 0.88).

3 Boyutlu Bina Modelleme ve WEB Tabanlı Sunumu: Ahmet Necdet Sezer Kampüsü Örneği

The developments in technology in recent years have provided significant opportunities in the collection, processing and presentation of data. 3D‐modeling has been used in various areas; such as, virtual reality, virtual tours in the panoramic images, tourism and even virtual museums. In particular, the 360° panoramic tours have an increasing use in the promotional purposes and tourism in recent years. Places and locations are presented to users through virtual tours on the web. This study is realized in accordance with current base map of Ahmet Necdet Sezer (ANS) campus. All buildings in campus have been modeled in 3D and facedes were covered with real textures. The generated models have been transferred in to Google Earth. Moreover, the streets map of ANS campus has also been transferred in to web for virtual trip.