Yazar "Altunel, Erhan" seçeneğine göre listele
Listeleniyor 1 - 9 / 9
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Analyses of Seismic Deformation at the Kibyra Roman Stadium, Southwest Turkey(Wiley, 2013) Karabacak, Volkan; Yonlu, Onder; Doku, Eray; Kiyak, Nafiye Gunec; Altunel, Erhan; Ozudogru, Sukru; Yalciner, Cahit CaglarThe ancient city of Kibyra in southwest Turkey has the potential to reveal the location and date of historical earthquakes. The most compelling evidence for earthquake faulting is observed in the city's Roman stadium. Damage related to seismic shaking is characterized by systematically collapsed columns, dilated and collapsed walls, and by rotated and displaced blocks in the stadium. Detailed archaeoseismological observations suggest that Kibyra was affected by earthquakes that were also recorded in historical earthquake catalogs. Although there is no historical record of a large earthquake after the 5th century A.D., Optically stimulated luminescence (OSL) dating of deposits under the collapsed blocks suggests a later seismic event. OSL results indicate that another large event occurred in southwest Turkey, probably around the 10-11th century A.D., and caused extensive damage (I-o = VIII-IX) to the Kibyra stadium.Öğe Application of GPR to normal faults in the Buyuk Menderes Graben, western Turkey(Pergamon-Elsevier Science Ltd, 2013) Yalciner, Cahit Caglar; Altunel, Erhan; Bano, Maksim; Meghraoui, Mustapha; Karabacak, Volkan; Akyuz, H. SerdarPaleoseismology documents past surface-rupturing earthquakes that occurred on faults. This study is limited by the scarcity data on geomorphic and sedimentary environments that may preserve adequate records of deposition, erosion, and fault slip markers. Identifying relevant trenching sites can be difficult when a fault is buried or its surface expression has been eroded since the last tectonic motion. Ground penetrating radar (GPR) is an effective tool for locating suitable sites for trenching. Characteristic reflections are produced by boundaries between elements with contrasting electrical properties, such as grain size distribution (sorting, clay content, etc.), porosity, and water content. GPR is capable of resolving faults by imaging offset stratigraphic reflectors or reflections from the fault plane. GPR surveys were performed at two sites along the Buyuk Menderes Graben (western Turkey) to precisely locate the normal fault zone; there is no clear evidence of surface rupture at these sites. We used 250 and 500 MHz antennas for receiving the GPR data. From the GPR measurements, we determined locations suitable for paleoseismic investigations and performed a trenching study across the fault plane. The comparison of the GPR results and the trenching study indicates a good correlation between these methods. (C) 2012 Elsevier Ltd. All rights reserved.Öğe Eski Eserlerdeki Yapısal Tahribatların Termal Görüntüleme ve Mikrodalga Nem Ölçümleri ile Belirlenmesi: Ayasofya Müzesi Örnek Çalışması(Çanakkale Onsekiz Mart Üniversitesi, 2017-12) Yalçıner, Cahit Çağlar; Gündoğdu, Erdem; Kurban, Yunus Can; Altunel, ErhanÜlkemizde güncel olarak tarihi önem taşıyan binaların restorasyonuna büyük önem verilmektedir. Bu tarz önemli tarihsel geçmişe sahip binalarda restorasyon çalışması yapılmadan önce deformasyonların ve bozulmaların nedenini araştırmak da çok büyük önem taşımaktadır. Gelişen teknolojik aletler sayesinde restorasyon çalışmaları öncesinde deformasyon ve nedenlerini tahribatsız yöntemler ile belirlemekte mümkün olmaktadır. Yapımı M.S. 537 yılında tamamlanan ve İstanbul’un fethi sonrasında cami olarak kullanılmaya başlanan Ayasofya Müzesi’nin (Hagia Sophia) ana kubbesi, birçok kez çökerek hasara uğramış; 16. yy da ise Mimar Sinan tarafından yapılan istinat duvarı ve payandalar ile bu hasarlar önlenmeye çalışılmıştır. Ana kubbedeki bu hasarların yanı sıra, bina içerisinde de meydana gelen yapısal hasarlar mevcuttur. Bu hasarların önlenmesi amacıyla da, başta galeri katı olmak üzere binada bulunan taşıyıcı elemanlar, metal ve ahşap hatıllar ile desteklemiştir. Bu güçlendirmelerden sonra, bölgede birçok deprem meydana gelmesine rağmen, Ayasofya’da yıkıma yol açan bir deprem olduğuna dair herhangi bir kayıt bulunmamaktadır. Tüm bu güçlendirme çalışmalarının yanı sıra, 1930’lu yıllarda Mimar Fossatti kardeşler tarafından ana kubbeye tadilat ve güçlendirme çalışmaları da yapılmıştır. Günümüzde birçok ziyaretçi tarafından yoğun olarak ilgi gören Ayasofya’da, özellikle galeri katında zeminde ve duvarlarında yer alan bu deformasyonların varlığı dikkat çekmektedir. Yapı radarı sonuçlarında tespit edilen duvarlardaki bozulma ve deformasyonların nedeninin araştırılması amacı ile termal görüntüleme ve mikrodalga nem ölçümleri gerçekleştirilmiştir. Elde edilen sonuçların verdiği görüntü yapı radarının tespitlerine ışık tutacak şekilde olmuştur. Ayasofya Müzesi Galeri Katında yapılmış olan termal görüntüleme işlemi ve noktasal mikrodalga nem ölçümleri yapının maruz kaldığı ve kalacağı sorunları göstererek tahribatsız muayene işlemlerinde başarılı olarak kullanılabileceğini ortaya koymuştur. Bu tarz çalışmalar gerek tarihsel önemi gerekse günümüz ziyaretleri ile ekonomik önemi bulunan yapının korunmasında büyük önem taşımaktadır.Öğe Holocene Activity of Kutahya Fault Zone(Tmmob Jeoloji Muhendisleri Odasi, 2012) Altinok, Sevgi; Karabacak, Volkan; Yalciner, Cahit Caglar; Bilgen, A. Nejat; Altunel, Erhan; Kiyak, Nafiye GunecKutahya Basin which is located near the northeast boundary of the Western Anatolia Extension Region is a depression area that extends in WNW-ESE direction. Southern margin of the basin is bounded by a distinct fault morphology called Kutahya Fault Zone. Geological, geomorphological and geophysical studies on the Kutahya Fault Zone show that this zone consists of 5 different fault branches. Total length of the mapped fault zone is about 22 km in N50-70W direction. Paleoseismological and archeoseismological studies show that there are at least two surface rupturing earthquakes during the last 8000 years. First earthquake was occurred around 6000 BC and the last one was around 1800 B.C. after which the Seyitomer Tell was abandoned. Thus, this study indicates that the Kutahya Fault Zone has produced destructive earthquakes during Holocene and considering the length of the fault zone, it is possible to suggest that the fault zone has earthquake potential at least 6.5 magnitude.Öğe Kütahya fay zonu'nun Holosen aktivitesi(2012) Altınok, Sevgi; Karabacak, Volkan; Yalçıner, Cahit Çağlar; Bilgen, A. Nejat; Altunel, Erhan; Kayak, Nafiye GüneçBatı Anadolu Açılma Bölgesinin kuzeydoğu sınırında bulunan Kütahya Havzası BKB-DGD doğrultusunda uzanan bir çöküntü alanıdır ve güney kenarı belirgin bir morfoloji ile Kütahya Fay Zonu tarafından sınırlanmaktadır. Kütahya Fay Zonu boyunca jeolojik, jeomorfolojik ve jeofizik verilerden yararlanılarak yapılan çalışmalar sonucunda bu zonun, kuzey bloğun düştüğü normal fay geometrisine sahip 5 ayrı uzanımdan oluştuğu ve K50-70B doğrultusunda yaklaşık 22 km uzunluğa sahip olduğu ortaya konulmuştur. Paleosismolojik ve arkeosismolojik çalışmalar ise bu uzanım boyunca son 8000 yıl içinde yüzey kırığı oluşturan en az iki depremin meydana geldiğini ortaya koymaktadır. Bu depremlerden ilki M.Ö. 6000li yıllarda, sonuncusu ise M.Ö. 1800lü yıllarda Seyitömer Höyüğünde hasar oluşturan ve höyüğün terk edilmesine neden olan depremdir. Dolayısıyla, bu çalışmalar Kütahya Havzasının güneyini sınırlayan Kütahya Fay Zonunun Holosende tekrarlanan yıkıcı depremler ürettiğini ve geometrisi gözönünde bulundurulduğunda gelecekte de en az 6.5 büyüklüğünde deprem üretme potansiyeli bulunduğunu ortaya koymaktadır.Öğe Offset archaeological relics in the western part of the Buyuk Menderes graben (western Turkey) and their tectonic implications(Geological Soc Amer Inc, 2010) Yonlu, Onder; Altunel, Erhan; Karabacak, Volkan; Akyuz, Serdar; Yalciner, CaglarThe Buyuk Menderes graben is one of the most important active tectonic structures of western Anatolia. The graben extends for a distance of similar to 150 km between the Denizli Basin in the east and the Aegean Sea in the west, where its trend changes to NE-SW. The main active faults are located along the northern margin of the graben, some of which have been reactivated in surface-rupturing earthquakes during the twentieth century and the historical period. Detailed investigations along the NE-SW-trending part of the Buyuk Menderes graben showed that archaeological relics have been faulted by surface ruptures during the large historical earthquakes. The ancient city of Priene and an Ottoman bridge are located along the northwestern margin of the graben to the southwest of Soke and in Sazlikoy, respectively. Field observations and light detection and ranging (LIDAR) studies at both sites show that faulting has a normal component with considerable right-lateral movement. Offset archaeological features at both Priene and the Ottoman bridge are evidence for the reactivation of the graben boundary faults in the past 2000 yr. At Priene, a N-S-trending street wall is offset by 21 cm vertically and 10 cm dextrally, the eastern wall of the gymnasium is offset by 8 cm vertically, and the floor blocks of the agora are displaced by 26 cm vertically and 13 cm dextrally. The Ottoman bridge displays 76 cm vertical and 43 cm dextral offset to the southeast, which probably occurred during the 1846 earthquake.Öğe Paleoseismic history and slip rate along the Sapanca-Akyazi segment of the 1999 Izmit earthquake rupture (Mw=7.4) of the North Anatolian Fault (Turkey)(Elsevier Science Bv, 2018) Dikbas, Aynur; Akyuz, H. Serdar; Meghraoui, Mustapha; Ferry, Matthieu; Altunel, Erhan; Zabci, Cengiz; Langridge, RobertThe Sapanca-Alcyazi segment (SAS) is located on western part of the North Anatolian Fault (NAF) of Turkey. It was ruptured together with four other segments during the 17th August 1999 Izmit earthquake (M-w = 7.4) which caused similar to 145-km-long surface rupture in the east Marmara region. We conducted geomorphological investigations and 2D-3D paleoseismic trenching at 3 different sites near the Sakarya River along the SAS to obtain new data for the timing of past earthquakes and slip rate of this section of the NAF. Detailed investigations using Ground Penetrating Radar on the western bank of the Sakarya River reveal 18.5 +/- 0.5 m of right-lateral cumulative offset of an alluvial terrace dated as 850 +/- 11 years BP using Optically Stimulated Luminescence. The analysis of trench data from the three different sites of the SAS indicates the occurrence of four surface rupturing past earthquakes including the 1999 Izmit earthquake. According to the radiocarbon dating, these paleo-earthquakes can be correlated with the 1719 CE, 1567 CE, and 1037 CE historical earthquakes and suggest an average recurrence period between 273 and 322 years. The total dextral offset, the age of trench units and the terrace deposits together suggest a 22 +/- 3 mm/yr slip rate for this portion of the NAF.Öğe Reply to Comment on Analyses of Seismic Deformation at the Kibyra Roman Stadium, Southwest Turkey(Wiley-Blackwell, 2014) Karabacak, Volkan; Yonlu, Onder; Doku, Eray; Kiyak, Nafiye Gunenc; Altunel, Erhan; Ozudogru, Sukru; Yalciner, Cahit CaglarIn their comment, Elitez and Yaltirak (2013) criticize our paper (Karabacak et al. 2013) by arguing that it contains misinterpretations and unreliable data for a fault cutting the Roman Stadium in the ancient city of Kibyra. However their comments are not based on strong arguments to disprove our geological and archeological field observations or previous data. Here we present additional data supported by new figures which validate the faulting both in the bedrock and in the stadium floor. We reject their comments and uphold our original viewpoint on the faulting at the Stadium. (C) 2014 Wiley Periodicals, Inc.Öğe Research using GPR into the cause of cracks and depressions in the floor of the gallery of Hagia Sophia Museum(Elsevier Sci Ltd, 2017) Yalciner, Cahit Caglar; Kurban, Yunus Can; Altunel, ErhanHagia Sophia Museum is one of Istanbul's most important historical structures. Considering its location in Istanbul and the use of the building through history, visible damage is noted in the structure. To determine whether this damage noted on the exterior of the building is present in the interior, the gallery of Hagia Sophia Museum was scanned with ground penetrating radar. The GPR scanning of the floor of the gallery revealed the presence of weak zones in the floor and varying scales of deformation within the structure. Detailed study of the vaults showed that the geometrical symmetry of the curve of the vault dome was disrupted. The results obtained in this study show that necessary precautions should be urgently completed to prevent damage to Hagia Sophia, especially when the earthquake expected near Istanbul is considered. (C) 2017 Elsevier Ltd. All rights reserved.
