scholarly journals The Marmara Sea Gateway since ~16 ky BP: non-catastrophic causes of paleoceanographic events in the Black Sea at 8.4 and 7.15 ky BP

Author(s):  
Richard N. Hiscott ◽  
Ali E. Aksu ◽  
Peta J. Mudie ◽  
Michael A. Kaminski ◽  
Teofilo Abrajano ◽  
...  
Keyword(s):  
1995 ◽  
Vol 32 (7) ◽  
pp. 63-70
Author(s):  
I. Ethem Gönenç ◽  
Oguz Müftüoglu ◽  
Bilsen Beler Baykal ◽  
Ertugrul Dogan ◽  
Hüseyin Yüce ◽  
...  

Unlike other seas of the world, the Black Sea shows unique quality and trophic properties. Fortunately, only the upper layer water of the Black Sea is introduced into the Bosphorus and has a significant effect on the quality and trophic conditions of the Marmara Sea. These effects are discussed in the light of data obtained from collaborative efforts of Turkish and Romanian research institutions and processed satellite images. In conjunction with these discussions, recommendations for a suitable effluent disposal strategy for Istanbul's wastewater have been given.


1995 ◽  
Vol 32 (2) ◽  
pp. 141-148 ◽  
Author(s):  
I. S. Hansen ◽  
H. J. Vested ◽  
M. A. Latif

A modelling study of the hydrodynamics and spreading of wastewater from existing and future outfalls in the Bosphorus region has been conducted applying a 3-Dimensional model. The modelling is based on SYSTEM 3, which is a general modelling system for baroclinic flow simulating unsteady currents, waterlevels, salinity and temperature within the model area. The model set-up covers the Black Sea-Bosphorus-Marmara Sea junction area. The set-up is calibrated by data from a dedicated field program and previous field experience. The model is designed to describe the characteristic features of the flow in the junction area such as the effects of variations in waterlevel differences between the Sea of Marmara and the Black Sea on the important two-layer structure in the strait and the flow fields generated by the upper layer jet in the Bosphorus-Marmara junction. This model has been applied for evaluation of disposal of wastewater and for the subsequent water quality studies. The general use of a baroclinic 3-D hydrodynamic model to simulate disposal of wastewater is discussed. Examples of the application of the model of the junction area to evaluate the different strategies for disposal of wastewater are presented.


2019 ◽  
Author(s):  
Anastasia G. Yanchilina ◽  
Celine Grall ◽  
William B. F. Ryan ◽  
Jerry F. McManus ◽  
Candace O. Major

Abstract. The Marine Isotope Stage 3 (MIS 3) is considered a period of persistent and rapid climate and sea level variabilities during which eustatic sea level is observed to have varied by tens of meters. Constraints on local sea level during this time are critical for further estimates of these variabilities. We here present constraints on relative sea level in the Marmara and Black Sea regions in the northeastern Mediterranean, inferred from reconstructions of the history of the connections and disconnections (partial or total) of these seas together with the global ocean. We use a set of independent data from seismic imaging and core-analyses to infer that the Marmara and Black Seas remained connected persistent freshwater lakes that outflowed to the global ocean during the majority of MIS 3. Marine water intrusion during the early MIS-3 stage may have occurred into the Marmara Sea-Lake but not the Black Sea-Lake. This suggests that the relative sea level was near the paleo-elevation of the Bosporus sill and possibly slightly above the Dardanelles paleo-elevation, ~80 mbsl. The Eustatic sea level may have been even lower, considering the isostatic effects of the Eurasian ice sheet would have locally uplifted the topography of the northeastern Mediterrranean.


2018 ◽  
Vol 3 (4) ◽  
pp. 14-28 ◽  
Author(s):  
I. P. Bondarev

The name Flexopecten glaber ponticus (Bucquoy, Dautzenberg & Dollfus, 1889) is generally used for the only Pectinidae representative inhabiting the Black Sea. It is registered in the Red Book of the Republic of Crimea as endemic subspecies reducing in amount. F. glaber ponticus is listed in WoRMS MolluscaBase as the only accepted subspecies of Flexopecten glaber (Linnaeus, 1758). In the past its taxonomic status has been changed from a geographic variety to valid species. The purpose of this study is to establish its correct taxonomic status. The study is based on a comparative analysis of conchological features of Flexopecten glaber and F. glaber ponticus in relation with the brief natural history of population in the Black Sea. Sampling was performed by snorkel equipment in Kazach’ya Bay (Black Sea, Crimea, Sevastopol) at 2–6 m depths. A total of 100 scallop specimens were sampled in September 2017. To assure a better understanding in a broader context those results are compared with the previously published morphological data based on the analysis of a large amount of material from the Black Sea and the Mediterranean Sea – Marmara Sea regions. Comparative analysis of conchological features of F. glaber ponticus from the Black Sea with F. glaber from the Mediterranean region has not revealed any distinct differences between them. Thus, there are no evidenced data for the diagnosis of F. glaber ponticus as a subspecies. Species F. glaber appeared in the Black Sea not earlier than 7,000 years ago and formed a well developed population less than 3,000 years ago. We have to conclude that the specified divergence period is not long enough to form a subspecies. As a result of the present survey the subspecific status of F. glaber ponticus is not retained and the name is placed in synonymy of the parent species Flexopecten glaber.


2009 ◽  
Vol 6 (2) ◽  
pp. 1895-1911 ◽  
Author(s):  
L. Vandenbulcke ◽  
A. Capet ◽  
J. M. Beckers ◽  
M. Grégoire ◽  
S. Besiktepe

Abstract. In this article, we describe the first operational implementation of the GHER hydrodynamic model. This happened onboard the research vessel "Alliance", in the context of the Turkish Straits System 2008 campaign, which aimed at the real-time characterization of the Marmara Sea and (south-western) Black Sea. The model performed badly at first, mainly because of poor initial conditions. Hence, as the model includes a reduced-rank extended Kalman filter assimilation scheme, after a hindcast where sea surface temperature and temperature and salinity profiles were assimilated, the model yielded realistic forecasts. Furthermore, the time required to run a one-day simulation (about 5 min of simulation, or 10 min with pre-processing and data transfers included) is very limited and thus operational use of the model is possible.


2021 ◽  
Author(s):  
Mehmet Ilicak ◽  
Ivan Federico ◽  
Ivano Barletta ◽  
Nadia Pinardi ◽  
Stefania Angela Ciliberti ◽  
...  

<p>Marmara Sea including Bosphorus and Dardanelles Straits (i.e. Turkish Strait Systems, TSS) is the connection between the Black Sea and the Mediterranean. The exchange flow that occurs in the Straits is crucial to set the deep water properties in the Black Sea and the surface water conditions in the Northern Aegean Sea. We have developed a new high-resolution unstructured grid model (U-TSS) for the Marmara Sea including the Bosporus and Dardanelles Straits using the System of HydrodYnamic Finite Element Modules (SHYFEM). Using an unstructured grid in the horizontal better resolves geometry of the Turkish Straits. The new model has a resolution between 500 meter in the deep to 50 meter in the shallow areas, and 93 geopotential coordinate levels in the vertical. We conducted a 4 year hindcast simulation between 2016 and 2019 using lateral boundary conditions from CMEMS (https://marine.copernicus.eu/) analysis, in particular Black Sea Forecasting System (BS-FS) for the northern boundary and Mediterranean Sea Forecasting System (MS-FS) for the southern boundary. Atmospheric boundary conditions fare from the ECMWF dataset.</p><p>Mean averaged surface circulation shows that there is a cyclonic gyre in the middle of the basin due to Bosphorus jet flowing to the south and turning to west after reaching the southern Marmara coast. The U-TSS model has been validated against the seasonal in situ observations obtained from four different cruises between 2017 and 2018. The maximum bias occurs at around halocline depth between 20 to 30 meters.  We also found that root mean square error field is higher in the mixed layer interface. We conclude that capturing shallow mixed layer depth is very in the Marmara Sea due to the interplay of air-sea fluxes and mixing parametrizations uncertainties. Maximum salinity bias and rms in the new U-TSS model are around 3 psu which is a significant improvement with respect to previous studies. This new model will be used as an operational forecasting system and will provide lateral boundary conditions for the BS-FS and MS-FS models in the future.</p>


2010 ◽  
Vol 31 (2) ◽  
pp. 75-86 ◽  
Author(s):  
Atike Nazik ◽  
Engin Meriç ◽  
Niyazi Avşar ◽  
Selma Ünlü ◽  
Vildan Esenli ◽  
...  

2021 ◽  
pp. 23-62
Author(s):  
ELMAS KIRCI-ELMAS ◽  
ATIKE NAZIK ◽  
SEVINÇ KAPAN ◽  
ENGIN MERIÇ ◽  
EMINE ŞEKER ZOR ◽  
...  

İzmit Gulf is located between Kocaeli and Armutlu peninsulas at east of Marmara Sea and the interaction area of North Anatolian Fault Zone (NAFZ) and Marmara Graben systems. In this study, the faunal and floral contents (ostracod, foraminifer, mollusc and diatom) of the samples belonging to seven drilling cores were studied and obtained the radiocarbon and optically stimulated luminescence (OSL) age data in order to establish on the Black Sea – Marmara Sea - Mediterranean water connections and palaeoenvironmental changes. The sediments in this study are Late Pleistocene-Holocene aged and only cover the Marine Isotope Stages MIS-5 (interglacial), MIS-3 (an interstadial period between MIS-4 and MIS-2 glacial epochs) and MIS-1. The determination of ostracod and mollusc fauna of the Mediterranean and Ponto-Caspian origin provide important clues to water exchange between the Mediterranean and the Black Sea. Although some Mediterranean originated ostracods occur sporadically with low abundance, absence of foraminiferal fauna and existence of Ponto-Caspian ostracods together with fresh water and cosmopolitan diatom flora indicate that the area strongly interacted with the Black Sea waters during MIS-5. The faunal and floral characteristics of the sediments deposited during MIS-3, clearly denote that the Izmit Gulf was connected with the Black Sea and the Mediterranean Sea at the beginning of MIS-3 (ca. 52.0 - 40.0 ky BP) and the shallow shelf areas were frequently affected by both the Black Sea discharge and Mediterranean input. A thick Holocene sedimentary sequence recovered from the southern Hersek Burnu drilling cores reflects the environmental changes after the latest Black-Mediterranean seas connection. The studied ostracod and mollusc assemblages are mainly characterized by the Mediterranean originated species with a few relict Ponto-Caspian fauna. Also, the benthic foraminiferal assemblages are dominated by normal marine and euryhaline species, reflecting the salinity fluctuations in the Holocene interval.


Author(s):  
M. U. Gumusay ◽  
O. Ozdemir ◽  
T. Bakirman

Web based geographic information systems (GIS) has great potential based on developments in internet and web technology. Web based GIS is a network based tool that takes advantage of internet with visualizing, analysing and accessing of distributed data and analysis functions. With the length of 30 kilometres, the Bosphorus provides an essential zone that offers great maritime traffic services. This shipping way which connects The Black Sea and The Mediterranean Sea through The Marmara Sea, has no alternative and it is substantial for economies of Black Sea countries. The Bosphorus is one of most important natural straits in the world handling 150 transit ships, 23 freighters with dangerous cargo and 2500 local transport ships with 2 million passengers on daily basis. In this study, it is aimed to create a web based GIS application for an effective coast management which includes berthing factors (anchorage areas, currents, submerged, etc.), maritime traffic factors (traffic separation schemes, traffic flow directions), closed areas and other factors (lighthouses, buoys, beacons, etc.) by digitizing printed navigation charts produced by Turkish Naval Forces, Office of Navigation, Hydrography and Oceanography.


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