Sena Akçer-Ön

Mugla Üniversitesi · Department of Geological Engineering

X-ray element analyzes were carried out with the XRF detector, which moves symmetrically from the center, from the old ring to the youngest ring and again to the old ring, on the cross-sections of the trees which branches were broken in the snowstorm in February 2021 in Istanbul. In these analyzes, pine, poplar and peach fruit trees were scanned fr...

The sedimentary sequence in Lake Salda has been first documented in detail by analyses of high-resolution seismic profiles and sediment cores together with onshore outcrops along the present shoreline of the lake. Such a multi-proxy approach provides a strong record of changing lake levels and depositional conditions in Lake Salda during the mid to...

A high-resolution multiproxy lake sediment dataset, comprising lithology, radiography, μXRF elemental, magnetic susceptibility (MS), δ ¹³ C, and δ ¹⁸ O measurements since ca. AD 400 is presented in this study. Changes in lithology, radiography, magnetic susceptibility (MS), δ ¹³ C, and δ ¹⁸ O reflect wet/dry climate periods, whereas variability in...

Climate reconstructions derived from proxy records for individual sites often fail to incorporate existing regional information, which may help to determine uncertainties and express variability within specific reconstructions or commonalities between datasets. Such an understanding is crucial when examining past human-environment interactions. Tak...

Supplementary figures and tables for the main article.

The sedimentary sequence in Lake Salda has been first documented in detail by analyses of high-resolution seismic profiles and sediment cores together with onshore outcrops along the present coastline of the lake. Such a multi-proxy approach provides a sensitive record of changing lake level and depositional conditions in Lake Salda during the mid-...

We report high-resolution multiproxy analyses [lithology, μXRF and magnetic susceptibility (MS)] of two short gravity sediment cores from the crater Lake Gölcük, southwest Turkey. Our results provide a detailed hydroclimatic record for the last ~290 years. Aided with factor analysis of μXRF data and 210 Pb and 137 Cs dating, our multiproxy data sho...

It is the result of this study that the presence of ettringite mineral in both types of concrete, helps new term named as ' natural Salda concrete ' . Its definition and similarity provement provided for natural concrete with portland cement user artifical concrete's well known Ettringite mineralization at civil engineering by aluminum & sulfide re...

It has been proposed that there was an abrupt climatic change event around 4.2 ka BP that affected societies and even has been linked to the collapse of empires. Subsequent studies have reached conclusions that both support and contradict the proposed event yet, nevertheless, 4.2 ka BP has now been adopted as the stratigraphic boundary point betwee...

The ancient Gulf of Latmos is an iconic example of a dynamic landscape and humankind's historical relationship with it. Using extensive new primary data and original models for calibrating radiocarbon dates in transitional lagoon environments, we demonstrate that Lake Bafa (or Bafa Gölü, in Turkish) formed at a much earlier date than previously tho...

Holocene climate changes of the NW Anatolia is well-resolved by means of high resolution speleothem (Sofular Cave) and sedimentary (İznik, Çubuk Lakes and Black Sea) records. The Sakarya River, the major fluvial system of the region, comprise 3 stepped depositional terrace staircases located just to the south of the North Anatolian Fault at the Ada...

Modern hydrated Mg rich stromatolites are actively growing along the shallow shorelines of Lake Salda (SW Turkey). An integrated approach involving isotopic, mineralogical, microscopic, and organic/geochemical techniques along with culture-independent molecular methods were applied to various lake samples to assess the role of microbial processes o...

Lake Salda is very unique lake similar to Maldives white coastlines, different natural mechanisms are keeping its specifications. The plant acids are harmful to magnesites, but also reed vegetative small side lakes provides enough calcium on to thin shield of magnesite for prevent damage.

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Pratik serbest valfli sediment deformasyonsuz htbrid gravite cekic karotiyer Practical free-valve sediment deformation-free hybrid gravity-hammer corer

In order to understand the hydroclimate changes recorded in the Lake Gölcük (Isparta, SW Anatolia) sediment records, two short gravity sediment cores have been recovered. The sediment cores, with lengths ranging from 15-21 cm, have been analysed by micro-XRF at 0.5 mm and Multi Sensor Core Logger (MSCL) at 1 mm intervals. The short cores have also...

With global warming looming (causing low agricultural yield, natural disasters e.t.c), current studies have enlisted the Mediterranean region as one of the hotspots for climate change. One of the time-frame to help in understanding the current global warming is the Late Holocene. Therefore, studies of the Late Holocene climate changes are of huge i...

In their manuscript, Bradley and Bakke (2019) compile marine and terrestrial records from the North Atlantic, north of 60◦ N, to discuss the existence or otherwise of an abrupt climatic change around 4.2 ka BP across this extensive region. Their discussion is mainly based on data which do not conform to that expected of such an abrupt event. Accord...

Climate variability is a well-known phenomenon and has been frequently, though complex, linked to solar forcing on different time scales. The importance of solar forcing related climate variability is crucial in our understanding of paleoclimate and future climate changes, as well as building climate models. Here in, we present the late Holocene (l...

This article analyses high-quality hydroclimate proxy records and spatial reconstructions from the Central and Eastern Mediterranean and compares them with two Earth System Model simulations (CCSM4, MPI-ESM-P) for the Crusader period in the Levant (1095–1290 CE), the Mamluk regime in Transjordan (1260–1516 CE) and the Ottoman crisis and Celâlî Rebe...

ÖZET Paleovejetasyonun değişimi, geçmiş iklim çeşitliliğinin belirlenmesinde kullanan iyi bir belirteçtir (proxy). Bu çalışma kapsamında, Uludağ Aynalı Göl'den 650 mm uzunluğunda gravite karot alınmış ve 10 mm aralıklarla polen tür tayini yapılmıştır. Aynalı Göl, Uludağ (KB Anadolu) zirvesinde bulunan buzul gölüdür ve 2310 m rakımına sahiptir. Ka...

Sediment archives provide crucial information about past climate and environment conditions, and are commonly investigated by using different proxies (e.g. sediment properties, geochemistry, and fossil assemblages). In dynamic coastal environments, changing processes make the proxy interpretation difficult to reconstruct complex environmental setti...

The results of Density measurement has relative characteristics belong to changing conditions even at measurement time. The compression load related physical and chemical changings or lithologic metamorfism is out of this paper's scoop as other effects releated on all stages of storage and measurement processes. We know that all changings provide h...

Lake Van, which is the largest soda lake of the earth, lies in the Eastern Anatolian High Plateau. Two different composite cores, that span the last 250 kyr and 90 kyr, were drilled in Lake Van within the framework of PALEOVAN project (ICDP). In order to test the theories of quasi-periodic behavior of climate, generated by astronomical and solar fo...

The recent carbonate precipitation occurs in Lake Acigöl, a hypersaline playa lake. Elucidating precipitation mechanisms of carbonate minerals under particularly supersaturated ionic solution at low temperature may hold key understanding to recognize microbial fingerprints throughout the Earth history. In the presented study abiotic and microbial f...

High-resolution seismic reflection profiles and core analyses in Lake Hazar provide a detailed record of the lake level fluctuations and the robust chronology of paleoclimatic events of the Eastern Anatolia during the late Pleistocene to Holocene. The earlier period of Marine Isotope Stage 3 (MIS-3) prior to 48 cal ka BP was accompanied by consider...

The elemental composition of lake sediment cores is often the result of several independent processes. In this study we attempt to extract statistically independent climate related signals from m-XRF multi element data of a core drilled from Lake Hazar in Eastern Anatolia, using the independent component analysis (ICA) method. In addition, we analy...

Corers used for sediment sampling in marine and lake geological studies can be classified into four main systems. These are gravity, hydraulic direct pusher, piston hammer, and the hybrid model systems. The last corer system shares the specifications of the previous three corer types. We need one directional valve systems for keeping sediment sampl...

Non-pollen palynomorphs (NPPs) are usefull indicators to evaluate paleoenvironmental changes. They have a wide range, and are mainly encountered on pollen slides, with providing complementary insights for climate and/or human-driven soil and vegetation patterns. In order to investigate paleoecological variations based on non-pollen palynomorph ass...

In this research, we present high-resolution multi proxy evidences of past climatic records from Lake Salda, SW Turkey. Lake Salda is a tectonic and alkaline lake located at an elevation of 1180 m asl. Dating methods based on Pb-210, Cs-137 and C-14 indicate that the sediment cores cover the period between AD 613 and AD 2014 with a resolution at de...

Lake sediments are commonly used for environment studies and reconstruction of past climates. High resolution multiproxy analyses in undisturbed lake sediments can provide information about climatic changes on annual to seasonal scales. Salda is a tectonic lake at 1200 m altitude and located in the western Burdur province, SW Turkey. It is an alka...

Acıgöl (Denizli), in the Aegean Region, is a tectonic, salty, playa lake that has high values of Total Dissolved Solids (TDS) due to evaporation. The lake of Miocene-Pliocene age, is located at a NW-SE trending graben and surrounded by alluvium. The area is mostly covered by limestones, clastic sediments and ophiolites. Lake Acıgöl is located at 84...

Lake Salda located in south-western Anatolia is characterized by the presence of living stromatolites and by a low diversity of both phytoplankton and zooplankton due to high pH and magnesium concentration. The most abundant, free sedimentary lipids of the uppermost centimetres of the lake sediments were studied as potential environmental biomarker...

We studied microbial diversity of the lake Acıgöl, a hypersaline lake in the southwestern part of Turkey, and their influences on carbonate formation. Carbonate precipitaiton experiments were conducted under various conditions (temperature, Mg/Ca ratio and salinity) with the microorganims isolated from different part of the lake. O, S and C isotope...

ABSTRACT Biogenic carbonates formed under different conditions are geochemical archives which carry geochemical characteristics of the formation conditions. Interpretation of geochemical data preserved in the present and past geological conditions primarily depend on elucidating the role of microbial activities on carbonate formation. Discovery of...

Due to the variability of the Little Ice Age (LIA) and Medieval Climatic Anomaly (MCA), several climatic forcing mechanisms have been invoked to enlighten the issue. The focus of this study is on the influence of the solar activity proxy (Total Solar Irradiance) during the LIA and MCA in a high altitude Lake Salda in southwestern Anatolia. In order...

The core retrieved from Lake Van consists of seismites that were possibly deposited during the earthquakes around the Van region. Deformed parts of the core sediments display folded laminations that can be attributed to seismites. The problem arises that if the fold axis is deposited perpendicular to the liner and, if the hinge line is far enough,...

Physical parameters such as Magnetic susceptibility measurement gives a better results with U-channel sample form. Sensor magnetic field is focusing more than the half core form. We tried mm scale physical measurements of Thin U form for understand correlation quality with elemental scans at the same level's.Mechanical features in-stu drilling for...

The Lake District, located in the SW Anatolia region of Turkey, hosts a number of lakes with unique water chemistry. Among them, Lake Acigol, Lake Salda and Lake Yarisli display extreme biogeochemical conditions. In terms of their water chemistry and diverse prokaryotic community, each lake sets a great example for microbially mediated reactions (e...

Sediments in lakes are useful as tracers of past climatic and environmental changes. Salda Lake located at about 1150 m above sea level could give one of the finest archive for such studies. In light of this, five (5) gravity cores were recovered on a floating platform. The first core was used for 210 Pb and 137 Cs dating whereas the other four wer...

68. Geological Congress of Turkey

Day by day, human impact on water and environment has increased. Protection of water in lakes is of great importance interms both for usage and irrigation. Environmental changes in Lake Salda for the last 100 years research, is aimed at presenting the impacts of agricultural areas, home and industrial wastes on the lake. The Lake is a located in Ye...

Poster Presentation

Poster

New sediment cores were recovered from two sites in the central part of Lake Iznik with the overall aim of reconstructing past environmental conditions of the Marmara region. The composite profile presented here, IZN09/LC2&LC3, encompasses the late Pleistocene to Holocene transition (c. 36 ka cal BP) which is the longest lacustrine record in this r...

The Marmara region is a key area to investigate the interconnection and environmental changes between the Black Sea and the Eastern Mediterranean related to climate patterns. Lake Iznik is an oligohaline lake located in the southeast of the Marmara Sea. To decipher the long-term signals recorded in the sediment column requires better understanding...

The identification of past connection routes between the Black Sea and the Sea of Marmara, other than the traditional one through to the Bosphorus Strait, would be of considerable interest to the international scientific community. Nazik et al. (Geo-Mar Lett 31:75–86 (2011) doi:10.1007/s00367-010-0216-9) suggest the possibility of two alternative w...

The identification of past connection routes between the Black Sea and the Sea of Marmara, other than the traditional one through to the Bosphorus Strait, would be of considerable interest to the international scientific community. Nazik et al. (Geo-Mar Lett 31:75–86 ( 2011 ) doi: 10.1007/s00367-010-0216-9 ) suggest the possibility of two alternati...

The comparison of multiproxy analysis from several short and long cores, which were drilled in different field campaigns since 2002 in Lake Iznik (NW Turkey), the biggest freshwater lake in the Marmara region, allows us now to reconstruct the regional climate and depositional history. Last long cores from 2009 with a maximum length of 14 m extend t...

The late Holocene activity of a restraining bend of the northern strand of the North Anatolian Fault in Izmit Bay was investigated by a sedimentological, geochemical, and paleoecological analysis of sediment cores from Hersek coastal lagoon, NW Turkey. The sediment cores show a succession of sedimentary sequences composed of three units separated b...

The term 'Instantaneous Cable Hit' is not defined in technical papers, possible reason of its absence is belong to unconsideration by experienced technical people. But it has serious and important effect for seafloor equipment deployment operations. A striking effect can reach several tones in milliseconds at the impact point between steel rope and...

The late glacial to Holocene sedimentary record of the northern shelf of the Sea of Marmara (SoM) has been documented by detailed seismo-, chrono-, and biostratigraphic analyses using sub-bottom (Chirp) profiles and sediment cores. During MIS 3 and the main part of MIS 2 (60–15 14C ka b.p.), disconnection from the Mediterranean and Black seas toget...

The ten study cores obtained from the northern shelf of the Sea of Marmara (also see Fig. 1; mbss meters below sea surface)

Uncalibrated AMS and conventional 14carbon dates (without reservoir correction and without calibration to tree rings) in cores (mbss meters below sea surface, mbsf meters below seafloor)

We present the results of mineral magnetic measurements (χ, SIRM, ARM, NRM) and geochemical XRF Core Scanner elemental analysis from four cores located in water depths of 60-80 m in different parts of Lake Van, eastern Turkey. Lake Van is the fourth largest terminal Lake in the world by volume (607 km 3). It is 460 m deep and has a salinity of 21.4...