No abstract

içerisinde yer alan Bolvadin yerleşim alanında gözlenmektedir. Bu alanda, bir kısmı imar planı içerisinde kalan bölge ile şehrin güneybatı kısmından başlayarak kuzeydoğu istikametine doğru yer alan bölgelerde, son 4 yıldan itibaren daha önceden olmayan bazı deformasyonlar oluşmuş ve oluşmaya devam etmektedir. Bölgede yapılan çalışmalarda, yıkıcı deprem olmaksızın, uzunlukları 300 metre ile 2 km; doğrultuları ise K15°D ile K70°D arasında değişen hareketler ve yarılmalar şeklinde gelişen kademeli yüzey deformasyonları haritalanmıştır. Yerleşim alanı içerisinde haritalanan yüzey deformasyonlarının en kuzeyde olanı Bolvadin Fayı'nın güneybatıdaki devamı niteliğindedir. Yapılan jeolojik ve jeomorfolojik analizler yüzey faylanmaları boyunca, güneydoğuda yer alan bloğun 10-40 cm arasında düştüğüne işaret etmektedir. Yapılan jeodezik analizler bölgedeki son dört yıllık düşey yerdeğiştirme hızının 7,1 cm/yıl olduğunu göstermektedir. Bu sonuçlar, Bolvadin Fayı boyunca gelişen yüzey deformasyonlarının önemli bir nedeninin, yeraltı su seviyesi düşüşüyle ilgili olduğunu göstermektedir. Söz konusu yüzey deformasyonlarının oluşumuna, bölge tektoniğinin katkısını ortaya koymak için hendek tabanlı paleosismolojik çalışmalara ihtiyaç vardır.

Real-time kinematic (RTK) technique is important for mapping applications requiring short measure time, the distance between rover and base station, and high accuracy. There are several RTK methods used today such as the traditional RTK, long base RTK (LBRTK), network RTK (NRTK), and precise point positioning RTK (PPP-RTK). NRTK and LBRTK are popular with the advantage of the distance, the time, and accuracy. In the present study, the NRTK and LBRTK measurements were compared in terms of accuracy and distance in a test network with 6 sites that was established between 5 and 60 km. Repetitive NRTK and LBRTK measurements were performed on 6 different days in 2015-2017-2018 and additionally 4 campaigns of repetitive static measurements were carried out in this test network. The results of NRTK and LBRTK methods were examined and compared with all relevant aspects by considering the results of the static measurements as real coordinates. The study results showed that the LBRTK and NRTK methods yielded similar results at base lengths up to 40 km with the differences less than 3 cm horizontally and 4 cm vertically.

The Sultandağı Fault is an active dip-slip normal fault bounding the southeastern border of the NW-SE striking Afyon-Akşehir Graben, an actively growing rift area in western Anatolia. The historical and instrumental earthquake record suggest the existence of a large number of earthquakes that created surface ruptures in this system. The recent activities of the Sultandağı Faul twere evidenced bytwo earthquakes that occurred on February 3, 2002 (Mw=6.3 and Mw=6.0) and caused a surface rupture up to 26 km along with an approximately 30 cm vertical displacement. The possible continuation of this earthquake migration towards the west, seismic gaps existing in the region, the presence of historical destructive earthquakes, and the active faults reveal the seismic hazard around the province of Afyonkarahisar. In this study, we determined the fault activities and stress directions in the western part of the Sultandağı Fault by comparing the results from the Palaeostress analysis of fault segments, focal mechanism solutions of recent earthquakes and geodetic analysis. The geologic, geodetic and earthquake data all indicate that both northern and southern master faults of the middle part of the Afyon-Akşehir Graben are dip-slip normal faults and were shaped under a NW-SE and NE-SW-directed bimodal extensional tectonic regime during the Quaternary-Holocenethe period.

In the actively deforming region of western Anatolia, crustal deformation is accommodated by destructive earthquakes and a variety of aseismic events. In this study, we investigated the 2016–2017 aseismic sequence located in the Bolvadin Fault, one of the segments of the Akşehir-Simav Fault System of western Anatolia by analysing surface deformation derived from detailed geological mapping. Our findings suggest that surface deformation in the Bolvadin Fault is accommodated by aseismic episodes. During the field studies in the Bolvadin area, progressive surface deformations, such as surface faults and earth fissures with a length of 800 meters to 3 kilometres and strike of N15°E to N70°E were mapped on a 1/5000 scale. Furthermore, a levelling network was established to calculate the vertical displacements and deformation rate along the surface deformations. Precision level measurements were undertaken in 2016 and 2017. On the routes to the NW of the Bolvadin settlement, a vertical deformation rate of 30 mm/yr was detected in the period of 2016–2017, and a large deformation rate of 40 mm/yr was detected in the same period.