Constraints on unconsolidated pyroclastic flow sediments related REE enrichments originated from potassic-alkaline Gölcük stratovolcano: Darıdere-Direkli-Yakaören (DDY) table 4deposits,southwestern Anatolia of Turkey     

Budakoglu  Murat  Unluer  Ali Tugcan  Doner  Zeynep  Kocaturk  Huseyin  Kaya  Mustafa  Kumral  Mustafa  Kirikoglu  M. Sezai 《中国地球化学学报》2021,40(6):926-944

Acta Geochimica - In the last five decades, Rare Earth Elements (REE) are mostly produced from carbonatite complexes and alkaline magmatic environments. In this respect, pyroclastic flows produced...  相似文献   

Changes of oceanographic characteristics and the state of pollution in the Izmit bay following the earthquake of 1999     

Enis Morkoc  Legovic Tarzan  Oya Okay  Huseyin Tufekci  Vildan Tufekci  Leyla Tolun  Fatma Karakoc 《Environmental Geology》2007,53(1):103-112

The Izmit Bay is an elongated semi-enclosed bay in the Marmara Sea. It is being increasingly polluted by both domestic and industrial waste discharge since 1970’s. A monitoring program was conducted between 1999-2000 to document the state of pollution in the bay. This includes the effect of Marmara (Izmit) earthquake (magnitude 7.4) that occurred in August 1999. A stable two-layer ecosystem exists in the bay throughout the year due to continuous inflows of the saltier Mediterranean and brackish Black Sea waters to the Marmara basin. Therefore, the principal biochemical characteristics of the bay are governed by the two-layer flow system over the basin. Dissolved oxygen (DO) is generally at a saturated levels in the surface layer which is 10 to 15 m thick, but it is depleted to 60–70 μM in the lower layer, exhibiting a steep gradient in the sharp halocline. When the earthquake occurred, great loads of industrial wastes were released into the bay surface waters, which enhanced primary production in the upper layer and thus large export of particulate organic matter to lower layer and eventually to the bottom. Accordingly, DO was consumed and anoxic condition was established even in the upper layer/halocline interface, the halocline and bottom waters of the eastern and central bay. In this period, concurrent increases were observed in phosphate and ammonia contents at the halocline and in deep waters whilst the nitrate was almost consumed via denitrification processes in the anoxic water. Recently, the industrial C, N and P loads increased by as much as 8 fold within five years (1995–2000) whilst domestic inputs increased by 50%. Total organic matter discharged to the bay increased more than double within the last 15 years. Besides, most factories in the region release toxic wastes into the bay after only partial treatment.  相似文献   

整数模糊度参数的快速检索算法   总被引：1，自引：0，他引：1  

葛茂荣  Huseyin Baki Iz  陈永奇 《测绘学报》1998,27(2):99-104

ＧＰＳ快速定位中,由于模糊度参数之间的强相关性,模糊度参数置信区间定义的检索区域比相应的置信椭球大得多。本文通过模糊度参数向量的正交变换,定义出包含模糊度参数置信椭球的最小正交多面体,借助在其中构造的均匀正交网格点,找出置信椭球中的所有整数模糊度参数向量。该方法显著地减少了整数模糊度参数的检索范围,提高了计算效率。  相似文献   

Newly discovered mud volcanoes in the Coastal Belt of Makran,Pakistan—tectonic implications   总被引：1，自引：1，他引：0  

Akhtar M. Kassi  Shuhab D. Khan  Huseyin Bayraktar  Aimal K. Kasi 《Arabian Journal of Geosciences》2014,7(11):4899-4909

The Makran accretionary wedge has a much larger number of mud volcanoes then those reported earlier. Using high-resolution satellite images, over 70 active mud volcanoes were identified. These mud volcanoes occur within a well-defined zone; we call it the Makran zone of active mud volcanoes (MZAMV), which is parallel to the regional trend of the accretionary wedge. Mud volcanoes within the zone occur as clusters, which form linear belts parallel to the regional thrusts associated with anticlines. The MZAMV zone also includes the offshore mud volcanoes occurring in the shallow shelf area, including the recurrently emerging mud islands. Several occurrences of thick deposits of old mud volcanoes (Pleistocene or even older) are also present within this zone, which also display recognizable features that are characteristic of the fossil mud volcanoes. We propose that the MZAMV developed and evolved in response to the continued compression within the Makran accretionary wedge, which in turn, is a response of the subduction process. Mud diapirism has been an ongoing phenomena since Pleistocene or even earlier. The events of enhanced mud extrusion in mud volcanoes and/or emergence of island(s) have relevance with seismic phenomena and, therefore, may be closely monitored.  相似文献   

Discovering a pull-apart basin using InSAR in Bursa,Turkey     

Hakan S. Kutoglu  Huseyin Kemaldere  Tomonori Deguchı  Mustafa Berber 《Natural Hazards》2014,71(1):871-880

The city of Bursa in Turkey is surrounded by major and secondary fault branches which splay from the North Anatolian Fault. Nonetheless, as their traces were not exactly known in the alluvial land of the Bursa basin, until this study, they were not plotted in the official active fault map of Turkey. In this study, the Bursa basin was observed by InSAR technology, and the subsidence which is consistent with the pull-apart basin geometry was detected in the basin. This finding was discussed in the local platforms in Turkey. Then, the city of Bursa was included into the priority provinces for the urban reconstruction under the risk of an earthquake, and the official active fault map of the region was revised by General Directorate of Mineral Research and Exploration of Turkey.  相似文献   

Quantification of the urban heat island under a changing climate over Anatolian Peninsula     

Huseyin Ozdemir  Alper Unal  Tayfun Kindap  Ufuk Utku Turuncoglu  Zeynep Okay Durmusoglu  Maudood Khan  Mete Tayanc  Mehmet Karaca 《Theoretical and Applied Climatology》2012,108(1-2):31-38

The Anatolian Peninsula is located at the confluence of Europe, Asia, and Africa and houses 81 cities of which 79 of them have population over 100,000. We employed some criteria to select the cities from the 81 cities. After accomplishing all the criteria, eight cities were remaining for the study. Nonparametric Mann–Kendall test procedure was employed for the urban and rural stations of these cities to detect the long-term change in temperature trends. Statistical analysis of daily minimum temperatures for the period between 1965 and 2006 suggest that there is no statistically significant increase in rural areas. In contrast to the findings of the previous studies, however, all the urban sites and difference between urban and rural pairs show significant increase in temperatures, a strong indication for the existence of urban heat island (UHI) affect over the region. Regional Climate Model was also utilized to assess the changes in temperature by the end of century for the region. The findings suggest that an increase of up to 5°C is possible. Climate change effects enforced with UHI have the potential to cause serious problems for the entire region and hence needs to be studied thoroughly.  相似文献   

Modelling the magnetic field and differential rotation effects for the vicinity of the base of convective zone in the Sun     

Huseyin Cavus 《New Astronomy》2009,14(4):349-355

In this work, some numerical solutions of magnetohydrodynamics equations are investigated in the presence of differential rotation with the use of previously developed algorithm. This algorithm includes the thin shell approximation and a special separation of variables which were used to obtain the radial and latitudinal variations of physical parameters in spherical coordinates. The magnetic field profile is chosen to produce comparable magnetic fluxes found in previous works. The sphericity and density shape parameters relevant to model is determined by using two different known differential rotation profiles. It is found that the shape of variations in physical parameters is strongly dependent to magnetic field profile and there is a considerable change in density with respect to reference model. It is as well shown that the spherical symmetric distributions of physical parameters are broken for the region of study.  相似文献   

What about reservoirs? Questioning anthropogenic and climatic interferences on water availability     

Abdullah Akbas  Jim Freer  Hasan Ozdemir  Paul D. Bates  M. Tufan Turp 《水文研究》2020,34(26):5441-5455

Water resources in semi-arid regions like the Mediterranean Basin are highly vulnerable because of the high variability of weather systems. Additionally, climate change is altering the timing and pattern of water availability in a region where growing populations are placing extra demands on water supplies. Importantly, how reservoirs and dams have an influence on the amount of water resources available is poorly quantified. Therefore, we examine the impact of reservoirs on water resources together with the impact of climate change in a semi-arid Mediterranean catchment. We simulated the Susurluk basin (23.779-km²) using the Soil and Water Assessment Tool (SWAT) model. We generate results for with (RSV) and without reservoirs (WRSV) scenarios. We run simulations for current and future conditions using dynamically downscaled outputs of the MPI-ESM-MR general circulation model under two greenhouse gas relative concentration pathways (RCPs) in order to reveal the coupled effect of reservoir and climate impacts. Water resources were then converted to their usages – blue water (water in aquifers and rivers), green water storage (water in the soil) and green water flow (water losses by evaporation and transpiration). The results demonstrate that all water resources except green water flow are projected to decrease under all RCPs compared to the reference period, both long-term and at seasonal scales. However, while water scarcity is expected in the future, reservoir storage is shown to be adequate to overcome this problem. Nevertheless, reservoirs reduce the availability of water, particularly in soil moisture stores, which increases the potential for drought by reducing streamflow. Furthermore, reservoirs cause water losses through evaporation from their open surfaces. We conclude that pressures to protect society from economic damage by building reservoirs have a strong impact on the fluxes of watersheds. This is additional to the effect of climate change on water resources.  相似文献   

Adsorption of Fluoride on the Raw and Modified Cement Clay          下载免费PDF全文

Ayse Dilek Atasoy  Muge Ozdemir Sahin 《洁净——土壤、空气、水》2014,42(4):415-420

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Effect of soil amendments on phytoextraction potential of Brassica juncea growing on sewage sludge     

G. Dede  S. Ozdemir  O. Hulusi Dede 《International Journal of Environmental Science and Technology》2012,9(3):559-564

A pot experiment was conducted to investigate the influence of elemental sulfur, gypsum and chelating agent (Ethylenediaminetetraacetic acid) on copper, zinc, nickel, cadmium, chromium and lead uptake by Brassica juncea from sewage sludge. Addition of sulphur acidified the sludge, which caused the pH decrease to 5.4 with an initial pH 6.7. The shoot and root biomass were increased with sulfur addition, while decreased with Ethylenediaminetetraacetic acid addition. Applications of Ethylenediaminetetraacetic acid and sulfur resulted in a considerable increase in copper and lead concentrations in the plant. The highest root concentration of copper obtained to be 110?mg/kg?dw at Ethylenediaminetetraacetic acid treatment. For sulfur treatment, lead concentrations in shoots indicated almost high concentrations 77?mg/kg, about twofold increases relative to roots (34?mg/kg). The Transportation Index of all studied metals were quite low (TI?<?0.5), whereas the Bioaccumulation Factor values were much higher, varied from 0.01 to 9.67. Furthermore, the plant showed better Bioaccumulation Factor for copper and lead metals in both shoot and root. The efficiency to remove copper and lead from sludge is high in this plant. As a result, elemental sulfur will be effective amendment for phytoextraction of heavy metals from sewage sludge.  相似文献