Jeodezik çalışmalarla İzmit körfezi ve yakın çevresi kabuk deformasyonlarının belirlenmesi
Determination of crust deformations of İzmit region and its vicinity with geodetic studies
Yazar: MEHMET BAK
Danışman: PROF. DR. RAHMİ NURHAN ÇELİK
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / Geomatik Mühendisliği Ana Bilim Dalı / Geomatik Mühendisliği Bilim Dalı
Derece: Yüksek Lisans, 2014
Konu: Jeodezi ve Fotogrametri = Geodesy and Photogrammetry

Özet:
Kabuk deformasyonları belirleme çalışmaları çok eski yıllardan günümüze kadar farklı disiplinlerde çalışan bilim adamları tarafından yürütülmüştür. Jeodezik ölçme tekniklerinin bu çalışmalarda kullanılmaya başlanması ise 1900'lü yılların başlarına rastlamaktadır. Önceleri klasik yersel ölçme teknikleri ile yürütülen çalışmalar, teknolojinin gelişmesi ile EDM, VLBI, SLR gibi ölçme teknikleri ile gelişme ve genişleme imkanı bulmuştur. Özellikle GPS ölçme tekniğinin gelişmesi sadece jeodezi için değil tüm yer bilimleri için önemli bir kazanç olmuştur. 1980'li yıllardan itibaren GPS, klasik ölçme tekniklerini geride bırakarak, geniş kullanım alanı bulmuştur. 
Büyük yapıların planlanması sırasında, yapının oturacağı zeminde yapıya zarar verebilecek olası yer kabuğu hareketlerinin saptanması, daha sonra çevrenin yapıya etkileri veya yükleme nedeniyle yapıda meydana gelebilecek geometrik şekil değişmelerinin saptanması veya yapının çevreye etkisiyle çevrede meydana gelebilecek değişimlerin saptanması ya da salt yeryüzü kabuk hareketlerinin belirlenmesi için yapılan jeodezik ölçmelere "deformasyon ölçmeleri", bu ölçülerin değerlendirilerek deformasyonların saptanması ve yorumlanmasına da "deformasyon analizi" adı verilmektedir. Bilindiği gibi yeryuvarı, içerisinde sürekli bir hareketlenmenin yaşandığı dinamik bir yapıya sahiptir ve ülkemizin deprem olmaksızın hareketinin kuzeybatıya doğru yıllık ortalama 2-3 cm/yıl olduğu gerçeği  yeryuvarının ne denli hareketli dinamik bir yapıya sahip olduğunu açıkça ortaya koymaktadır. Bu hareketlerin sonucunda yeryüzünde meydana gelen yer ve şekil değiştirmelerin belirlenmesi ve kritik değerlerin hesaplanarak olası felaketlere karşı önlemlerin alınması son derece önemlidir.
Bu çalışmada, yapımına başlanmış İstanbul-İzmir Otoyolu Projesinin otoyol  kısmının önemli bir parçasının ve körfez geçişini sağlayacak köprünün güzergâhında kurulan deformasyon ağı ve Sürekli Gözlem Yapan Referans İstasyonlarının güncel durumları incelenmiştir. Kuzey Anadolu Fay hattının aynı güzergâhtan geçmesi nedeniyle tasarlanmış bu  deformasyon ağının değerlendiriliş stratejisi belirlenmiştir. 
Bu bağlamda, 2010, 2011 ve 2013 yıllarına ait tüm noktalar için baz çözümleri Leica Geo Office programında yapılmş ve sonuçları elde edilmiştir. Elde edilen bu baz çözümleri kullanılarak MATLAB de yazılmış olan dengeleme programı yardımıyla her periyoda ait dengelenmiş sonuçlar elde edilmiştir. MATLAB ile elde edilmiş olan dengeleme sonuçları kullanılarak tüm ağ noktaları için 3 Boyutta deformasyon analizi yapılmıştır. Bu analiz MATLAB de yazılan  3 Boyutta deformasyon analizi programı yardımıyla yapılmış ve analiz sonuçları elde edilmiştir.
Bu sayede 2010-2011, 2011-2013 ve 2010-2013 periyotları karşılaştırılmış ve  karşılaştırılan periyotlarda Sürekli Gözlem Yapan Referans İstasyonları'nın güncel durumlarının belirlenmesi ve deformasyon noktalarının durumları incelenmiştir.

Abstract:
Turkey, situated between Europe, Asia and Africa continents, is under the effect of the crustal deformation for ages. The recent earthquakes occurred since 1999 are resulted in a rise of crustal stress under the Marmara Sea. Since 1988, Marmara Region that carries the earthquake risk from the early times of the history, many studies executed by the contribution of number of organizations from different countries. As a result of these studies the earthquake risk on the region is revealed.
The designation of crust deformation studies are being executed by scientist work out with different disciplines since the very beginning. However, the geodetic measurement techniques began to be used during these studies only by the early 1900's. The previously studies executed with the classic terrestrial measurement techniques have found a way to progress and extend with the developing technology such as EDM, VLBI, SLR measurement techniques. Particularly, the development of GPS measurement technique became a very important gain, not only for geodesy but for all earth sciences. By 1980's, GPS far ahead of the classic measurement techniques, found expanding usage fields. 
VLBI, SLR like techniques keep the disadvantages of volumed, complex and expensive mechanisms which keep them away from the optimum campaign plannings. On the contrary, GPS consist of a portable receiver and an antenna. It makes it possible for every individual interested in these studies to own GPS as it gets cheaper by the developing technology. With GPS, high precision position determination for the designation of Crust deformation studies became easy, fast and cheap.
The geodetic measurements performed to determine possible deformations to take place in the ground that the construction is located, to detect the effect of the construction and the possible displacements in the surroundings, and the geometric deformations on the construction as a result of loading on it and to determine just the crustal movements on the earth are called as "deformation measurements", and the determination and the interpretation of the deformations through the evaluation of these measurements is named as "deformation analysis". Deformation surveys have an important status among engineering surveys. Results of the geometrical deformations that can occur in time in both in the environment that we are all living in and in the engineering structures that are build by human being concern the human life and safety closely. Therefore, recognizing, determining, and observing the geometrical deformations in engineering structures and its surroundings have great importance. As it is known, the earth has a dynamic structure in which has a permanent activation. The determination of displacements and deformations occurring at the end of these movements, and taking precautions against possible disasters by calculating the critical values are extremely important.
To investigate the deformations of an object or an area the geodetic observations are repeated at different epochs of time. The observations of each epoch are adjusted independently. From coordinate differences between the epochs the parameters of a deformation model are estimated and conclusions on the object deformations are drawn.
In this study, deformation network located in the route of Izmit Bay Bridge of the new Istanbul-Izmir highway project and current conditions of Continuously Operating Reference Stations are investigated. to a part of the North Anatolian Fault Zone passes from the region , this micro-geodetic network has been designed in the same route of bridge and part of the highway. Because of presence of the Continuously Operating Reference Stations in this region have determined the processing strategy of this network. Using of International Geodetic Networks that has continuously operating GPS/GNSS receivers on has been very common technique to define tectonic activities all over the world. By using these networks; more rapid, healthy and accurate 24-hour data can be obtained by scientific and engineering institutes. One of these kinds of networks is the IGS one that is an international network works whole over the world including Europe and it provides pool resources and permanent GNSS station data to generate precise GNSS products. There are 5 IGS stations in Turkey, two of them in the Marmara Region (near İzmit Gulf Region). ISTA and TUBI stations are located in for the Marmara Region. In addition to these international systems, there are some national and local systems such as TUSAGA (Turkish National Continuously Operating System's Network), TUSAGA-Active (Turkish National Continuously Operating System's Network- Active) and ISKI-UKBS (Istanbul Water and Sewerage Authority-Satellite Positioning Information System) which are active in Turkey can provide wide-ranged and more precise real-time positioning services. Turkish Real Time Kinematic (RTK) CORS-TR Network are called TUSAGA-Active established by Istanbul Kültür University in association with the General Directorate of Land Registry and Cadastre of Turkey and the General Command of Mapping of Turkey and sponsored by the Turkish Scientific and Technical Research Agency (TÜBİTAK). The network constitutes 147 Continuously Operating Reference Stations controlled by two control stations, the Master Control Station at the Department of Photogrammetry and Geodesy Administration of the General Directorate of Land Registry and Cadastre and the Auxiliary Control Station at the Headquarters of the General Command of Mapping of Turkey. Because of providing geometric strength, reference datum stability and of course redundancy to geodetic methods; TUSAGA-Active) is an important to national purpose. There are 6 stations in Marmara region to serve regional and local projects (the size of the rectangle is roughly 300 by 150 km). TUSAGA is another CORS network of the country and some of its stations are also member of IGS. This network has been established for same purposes by General Command of Mapping of Turkey. TUSAGA network has currently 26 stations actively. Six of these twenty six stations are dedicated as IGS stations. However, these stations have currently no real time facility to broadcast real time kinematic data. ISKI-UKBS (Istanbul Water and Sewerage Authority- Continuously Operating Reference Stations' Network) is a local network that works Istanbul and around, established by the Istanbul Water and Sewerage Authority- Satellite Positioning Information System.  There are 8 stations. They continuously (24-hour 7 days a week) records and broadcast GNSS data and rages in between stations are well optimizes, 50 to 70 km. The deformation network which has been processed for the pre-results has integrated these stations. Except of the pre-result of this network, there is another purpose of this study. Another purpose of the study is to determine updating situations of reference stations. The evaluation strategy of the deformation network is determined. Due to a part of the North Anatolian Fault Zone passes from the region, this micro-geodetic network was designed in the same route of bridge and part of the highway.
In this context, the study area and the study have been described, the main strategy of the study have been presented. Technical features and scope of international, national and local Continuously Operating Reference Stations of this area has been explained and described their efficiency in this region. In addition, the tectonic structure and the seismicity of the study area, the tectonic structure and seismic condition of the gulf and how to influence the route of the bridge and part of the highway will be constructed are discussed. Then,  The new Istanbul-Izmir highway project which causes a deformation analyze working in this region, have been focused on technical details. Finally, Design of the network and its measurement and processing and deformation analyzing strategies has been explained.
Base solutions of all points belong to 2010, 2011, and 2013 are done using Leica Geo Office program. By using these base solutions a stabilization program is written in MATLAB and balanced results of each period are obtained. Then three dimensional deformation analyses are performed for all network stations using these balanced results. Also, three dimensional analysis results are obtained with 3D deformation analysis program which is written in MATLAB.
Furthermore periods of 2010 - 2011, 2011 - 2013 and 2010 – 2013 are compared. In the comparison, the determination of current conditions of Continuously Operating Reference Stations and network stations are investigated.