Denizhan VardarIstanbul University · Institute of Marine Sciences and Management
Denizhan Vardar
PhD
About
47
Publications
11,257
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166
Citations
Citations since 2017
Introduction
Denizhan Vardar currently works at the Institute of Marine Sciences and Management, Istanbul University. Denizhan does research in Marine Geology and Geophysics.
Additional affiliations
December 2005 - present
Institute of Marine Sciences and Management, Istanbul University
Position
- Professor (Associate)
Publications
Publications (47)
High-resolution seismic data shed light on latest Pleistocene and Holocene sedimentation beneath the Büyükçekmece Bay, northern shelf area of the Marmara Sea, Turkey. Discontinuous fluvio-marine and marine deposits overlying the erosional truncation surface of Oligocene–Lower Miocene deposits are as thick as 30 m and preserved preferentially within...
Although there are many research studies on the northern and southern branches of the North Anatolian fault, cutting through the deep basins of the Sea of Marmara in the north and creating a series of pull-apart basins on the southern mainland, little data is available about the geometrical and kinematical characteristics of the middle strand of th...
High resolution Chirp and Sparker data allowed definition and mapping of distinct seismic units in the shallow sediment record (~100 ms) acquired from the southern exit of the Bosphorus Strait; a dynamic depositional environment. The bottommost unit observed in the Chirp data (unit-3) is made up of marine-lacustrine sediments thinning seaward and o...
High-resolution seismic survey was conducted to investigate acoustic characteristics of gassy sediments along the southern shelf of the Sea of Marmara. The acoustic turbidity zones outlined within the study area are generally below 2-9 m (2-10 ms TWT) the seafloor whilst this vertical distance varies between 9 and 21 m (10-25 ms TWT) for acoustic b...
New Chirp seismic data collected from the northern margin of the Marmara Sea in June 2015 and previous Sparker seismic profiles recorded in 1999 suggest a change in tectonic regime in Messinian. New tectonic lineaments and fault segments were detected at offshore the Çekmece lagoons region that is located on one of the possible water corridors with...
The high-resolution seismic reflection and magnetic data collected offshore of the Ganos Fault (NW Turkey) in the western Sea of Marmara in 2019, help to image the tectonic structures of the continental shelf between Tekirdağ and Şarköy . Based on these data a tectonic model, presents the connection of the onshore fault pattern to the transtensiona...
Since its location is on the northern branch of the active North Anatolian Fault (NAF), Izmit Bay is a critical basin for understanding the character of the NAF. Although the basin has been studied in detail by many researchers; available seismic reflection data do not provide sufficient and clear evidence to understand deep structures due to limit...
Küçükçekmece Gölü ve çevresindeki çalışma alanı, İstanbul'un güney kara alanının aktif tektoniğini anlamak için önemli bir rol oynamaktadır. Çalışmada bölgenin yakın yüzey yapısal özelliklerini anlamak adına yapılan jeofizik çalışmanın sonuçlarını verilmektedir. Küçükçekmece Gölü'nü çevreleyen alanda bir dizi jeo-elektrik veri toplanmıştır. Toplam...
The shelf between Tekirdağ and Şarkoy, NW Marmara Sea, is controlled by a major fault system, the Ganos Fault (GF), which is claimed to be the source of the 7.3 (Ms) earthquake in 1912. The effect of GF and global sea-level changes on of the shelf between Tekirdağ and Şarkoy was discussed on the basis of seismic-stratigraphic data. Two main units (...
Küçükçekmece Lake and surrounding land area play an important role to understand the active tectonism of the southern land area of Istanbul. This study gives the results of a geophysical survey to understand the structural features of the study area. We collected geo-electrical data on the surrounding Küçükçekmece Lake. Totally 14 different VES val...
Newly collected high-resolution seismic reflection and magnetic data collected offshore of the Ganos Fault (NW Turkey) in the western Sea of Marmara, along the submerged portion of the North-Anatolian Fault, highlight the presence of a complex fault pattern. Based on these data, we propose a new tectonic model for this key region, connecting the on...
The Ganos Fault, a part of the Northern strand of the North Anatolian Fault system, is an active-strike slip fault and divides the narrow NW shelf of the Sea of Marmara into two parts near the town of Gaziköy. This paper presents recently collected shallow high-resolution seismic data to discriminate the sedimentary successions, each characterized...
580-km length marine magnetic study was performed at the Northern Marmara Shelf and the Lagoon Küçükçekmece to provide new datasets to understand the submarine structures. The distributions of the relatively complex and differentiated low and high magnetic anomalies indicate that the study area was affected by the multiple tectonic regimes. While t...
A Correction to this paper has been published: https://doi.org/10.1007/s41208-021-00292-6
The Gulf of İzmit is a critical basin in assessment of the kinematics of the North Anatolian Fault (NAF) at the eastern margin of the Sea of Marmara. The available seismic reflection data do not provide sufficient and clear evidences to outline the deeper structures because of limited penetration. In agreement with the known main tectonic elements...
Recent sedimentation and Plio-Quaternary stratigraphy of northern Marmara shelf has been investigated by high-resolution seismic datasets. Seismic data indicate that a thin cover of Plio-Quaternary unit (termed Unit 1) overlies the Miocene/Oligocene age older sediments (termed Unit 2). The erosional surface between Unit 1 and Unit 2 is the regional...
This study focuses on the determination of the near-surface tectonic features in the eastern part of the Gulf of Saros, a highly active seismic region within the North Anatolian Fault Zone. Approximately 350-km-line high-resolution seismic data were acquired to understand the active tectonic setting of the inner side of the gulf. The Ganos Fault, w...
Submarine canyons are the significant morphological structures that related with oceanographic processes, mass movements, sediment transportation, productivity, and related biodiversity of benthic habitats between continental shelf and abyssal plain including slope. The specifications and relative influences of the canyon can be described by meanin...
The aim of the study is to improve the chirp seismic data quality by using two processing methods, to get more interpretable chirp data. For this purpose, we used for Chirp (2-8 kHz) seismic data. These were collected from the northern Marmara Sea. We also compare two processing methods (Quinn et al., 1998 and Baradello L., 2014) on our chirp data....
This study was held on the Gulf of Saros, which located on the North Anatolian Fault Zone, is a tectonically active region. The aim of this study to present the character and distrubition of the sedimentary deposits at the eastern part of the Gulf of Saros by using seismic stratigraphical methods. Previous studies that characterize the interior of...
Different Application of Ultrasonic Underwater Particle-Tracing
Probes at Deep Ocean Floor
Dursun Acar1.2,Bedri Alpar1, Tuncay Taymaz3,Seda Yolsal Cevikbilen3, Sinan Ozeren4,
Denizhan Vardar1, Tuna Eken3,Namik Cagatay 2,6, Sebnem Elbek5,Erol Sari1,K.Kadi Eris r2,6
(1.Istanbul University, Institute of Marine Sciences and Management, 2.Istanbul Techn...
This study is focused on the definition of tectonic elements in the Gulf of Saros, a highly active
seismic region within the North Anatolian Fault Zone. The previous reflection seismic studies
trying to characterize the structural setting of the gulf were not presenting sufficient and efficient
seismic data at the inner part of the gulf, so we stud...
The Gulf of Saros is located at the eastern margin of the North Aegean Trough (NAT), which is a
right stepping horsetail structure developed at the western termination of the North Anatolian
Fault (NAF). Its evolution started in the Middle to Late Miocene, under the NW–SE compression
caused by the counterclockwise movement of the Thrace and Biga pe...
The northern branch of the North Anatolian Fault (NAF) zone is the most active tectonic element in
the Marmara Sea and responsible for most of the seafloor and subsurface deformations observed along
the northern shelf. Various of these deformations are determined by using Chirp data. In this context,
Chirp seismic data were conducted in 2015. A tot...
A detailed identification of the structural elements along the North Anatolian Fault (NAF) in the Marmara Sea and their deformations on the seafloor and near surface strata is important to understand the kinematical features of the transform boundary between the Eurasian Plate and the Anatolian Plate, and future earthquakes. The northern branch of...
Highresolution seismic data collected at the northern shelf area of the Marmara Sea, Turkey, shed light on latest Pleistocene and Holocene sedimentation beneath the Büyükçekmece Bay area. Discontinuous fluviomarine and marine deposits above the erosional truncation surface are thin, mostly < 35 m, and preserved preferentially within incised valle...
Water-level variations in coastal areas and shallow channels take place under the influence of more complex factors, compared to those in deeper areas. Atmospheric pressure, wind, and wave interactions with bottom morphological characteristics are some important natural features while human-induced factors are usually maritime traffic and manoeuvre...
Shallow water conditions how effectable for scientific works. Professionals and their accidents.
wrong measurements etc
for look to details please download and use zoom of picture program
Maneuvering characteristics of the vessel in shallow water conditions are completely different than in deep water. The bathymetry and currents are the most important parameters for cruise and maneuvering of the ships, which can lost easily their steering control if these parameters are not taken into account seriously. The channel walls, coastal sl...
The behavior of seafloor sediment with its water column should be known against any occurrences of anoxic or oxic conditions. The most important ones of these conditions are possible leakage of natural gas or escape of liquids from sediment. On the basis of combined solid/liquid flow dynamics in sedimentation, such kind of events can change, even i...
Understanding the formation and evolution mechanism of the sandy deposits plays key role to define the hydrodynamics of the shelves and coasts. The barrier islands determined from high resolution chirp seismic reflection profiles, were started to deposit on the boundary (SB) that characterized by the lowstand stages of
global sea level in the south...
The stratigraphic setting and morphotectonic development of a wedge-shaped sand ridge, 2 km long and 600 m wide, on the southern approaches of the Strait of Istanbul has been investigated using high resolution chirp data. On a ravinement surface it is evolved during the post-glacial sea-level rise in the Sea of Marmara (late Pleistocene-early Holoc...
Cyzicus is one of the most important ancient settlement of Mysia region
on Marmara coasts in Turkey. It's located on Belkis Tombolo which
connects Kapıdağ (Arktonnesos) Peninsula to the shore. It
was established by the King Cyzicus Kyzikos in B.C. 749 as a Miletos
colony during the colonization movements of Ions. The main reason to
determine the es...
The concentrations of 12 polycyclic aromatic hydrocarbons (PAHs) were determined from 28 sediment samples taken from the Lake Iznik located in the north-west area in Turkey. Total concentration of the PAHs was observed as in the range of 17-835 ng g⁻¹ dry weight, with the highest values recorded offshore the cities of Iznik and Orhangazi, and the S...
Lake Iznik is a fresh water lake in the Marmara region and located on a highly tectonically active region along a plate boundary. Numerous destructive earthquakes occurred in the last 2,000 years, a few events accompanied with some abnormal waves. Due to its thick sedimentary deposits, high resolution seismic reflection data can only show uppermost...
Projects
Projects (3)
The shallow structural elements to be obtained from the geophysical and geological studies to be carried out in the sea and on the land will be interpreted together with the deep structural elements of the submarine. In addition, the general structural elements obtained will be interpreted together with the digital bathymetry and elevation model of the region, and the active faults that may have potential earthquake-generating potential in the bay will be digitized and mapped based on geophysical data and models for the first time. Then, considering the current stress tensor information, it will be determined which of the faults in the database, according to their types, are optimally oriented today. The relationship of this information with earthquakes occurring today will also be revealed. Similarly, active faults in the paleo stress regime will also be detected from the database. It is thought that important contributions will be made to the geodynamic evolution and seismotectonics of the region by using active faults in paleo stress and the current stress regime
Earth sciences studies carried out in the Marmara Sea shelves are inadequate. In particular, land-sea interactions of structural elements pose a significant threat the civil life due to the possible earthquakes. The spread of these studies are the important requirements for disaster prevention plans.
The North Anatolian Fault’s western segment, which extends from the western part of the Sea of Marmara to the Gulf of Saros, is known as Ganos fault. This segment caused a devastating earthquake of 7.4 magnitude on August 9, 1912. Although the general features of the main fault are coarsely known, there is no information about the sea extension of the second faults that mentioned in previous studies as to be parallel to the main fault on land. The main reason for this is that there is not enough datasets in the shelf.
The main aim of this proposed study; to determine the traces and recent deformations on the seafloor morphology between the Tekirdağ and Sarköy shelf and near coastal areas, the effects on recent sedimentary deposition related with Ganos fault and the secondary faults with the high-resolution marine geophysical datasets (seismic, magnetic and side scan sonar).
The morphological elements, slopes, deformations and lineaments in current and recent seismic units will be determined with high-resolution seismic data. The total magnetic anomaly map with sea magnetic data and the pole reduction, residual and regional maps to be obtained from it will be created and compared with the seismic data; the structural relationship between shallow effects and deep effects will be revealed. Side-scan sonar datasets will be used for determining the fault deformations that affects the sea floor and the morphological structures (delta, old coast, etc.). The bathymetry map and the faults properties that obtained from high-resolution data set will be used at NAMİDANCE simulation program to simulate TSUNAMİ risk, which can be triggered by possible earthquakes can be occurred at these faults. The results such as coastal advance and water height related with TSUNAMİ will be calculated.
Integrated interpretation of these obtained datasets will revealed the recent structural properties of the proposed study area and the effects on the coastal areas and the damages on civil life will be firstly discussed with this project
The main scope of this project is to determine and model the near surface deformations and its related structural elements of the northern branch of the North Anatolian Fault (NAF), which is the most active structure in the Sea of Marmara
