463 research outputs found

    Chukchi Edges Project - Geophysical constraints on the history of the Amerasia Basin

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    The geological history of the Amerasia Basin is poorly understood, in part due to the lack of identified plate boundaries within it. These boundaries must exist to explain the basin history. Identification of these structures will make it possible to reconstruct the development of the basin, which will substantially improve our understanding of the surrounding continents. The Chukchi Borderland, a block of extended continental crust embedded in the Canada Basin, figures prominently in all tectonic models proposed for the opening of the Amerasia Basin. The Chukchi cannot be simply reconstructed back to any of the nearby continental shelves. It complicates any model for the Mesozoic opening of the Amerasia Basin. According to the commonly accepted model, the Canada Basin opened like a pair of scissors. This was accomplished by a counter-clockwise rotation of the North Alaskan-Chukchi micro-plate (Arctic Alaska Plate) by 66 degrees. The micro-plate collided with the Siberian margin. Most of the existing models for the development of the Amerasia Basin accept the basic pattern of scissors-like or, classically, the “windshield wiper” opening for the basin. This theory finds some support in the identification of a possible relict mid-ocean ridge axis in the central Canada Basin. Since the continental Chukchi Borderland creates a space problem for any simple opening model, the greatest differences between models revolve around how to accommodate that block. Fundamental differences among the proposed models include the paleo-location of the Chukchi Borderland as well as whether the Borderland is a single entity or is instead comprised of small terranes which behaved as independent microplates. A consequence of these models is the prediction that the Chukchi Borderland is distinct from the Chukchi Shelf. During the Chukchi Edges cruise on board the RV Marcus G. Langseth, we collected multi-channel seismic reflection, swath bathymetry, gravity, magnetics and sonobuoy refraction data across the transition from the Chukchi Shelf to the Borderland. These data will establish new constraints on the timing and distribution of deformation in the development of the Amerasia Basin and provide a test of the windshield wiper model of basin opening

    History of the Chukchi borderland and the Amerasia basin, Arctic Ocean

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    Thesis (Ph.D.) University of Alaska Fairbanks, 2018Structural and stratigraphic interpretation of 2D multi-channel seismic (MCS) reflection profiles through recognition of the sub-surface reflection patterns and integration of the seismic interpretation with the other geophysical and geological data reveal the history of the Chukchi Borderland. This investigation provides new constraints for the tectonic development of the Amerasia Basin. North-striking normal faults of the Chukchi Borderland dissect the continental basement into the Chukchi Plateau, Northwind Basin and Northwind Ridge from west to east. A well-developed angular unconformity (Au) separates the stratigraphic section into sub and super-Au seismic units. Sub-Au units include: (1) seaward dipping reflections (SDRs) observed in the juncture between the North Chukchi-Toll Basins and Chukchi Plateau; (2) growth and folded strata in the Northwind Basin; (3) thrust faults in the Northwind Basin and over the Northwind Ridge; and (4) a clinoform sequence that downlaps onto the extended continental crust of the Canada Basin, supported by presence of SDRs and diapiric reflections within the crust. Au is inferred to correlate to the Hauterivian (LCu) and the Middle Jurassic (Ju) unconformities of the Alaska North Slope. The SDRs indicate that the southwestern margin of the Chukchi Borderland may be a rifted continental margin. Loosely constrained age control of a super-Au unit (inferred condensed section, perhaps correlative to Hauterivian pebble shale or the Jurassic upper Kingak shale units of Alaska North Slope) implies that the rifted margin subsided no later than the earliest Cretaceous, providing a plausible time constraint for Middle Jurassic-earliest Cretaceous rifting in the North Chukchi Basin. The growth strata and north-striking normal faults of the Northwind Basin are continuous with the extensional structures of the Mississippian Hanna Trough, providing a geologic linkage between the two. The folding and thrust faults reveal a phase of contraction confined to sub-Au units of the south and eastern Northwind Basin and Northwind Ridge. The clinoform sequence of the Northwind Ridge-Canada Basin is inferred to correlate with the Upper Jurassic-Lower Cretaceous Kingak shale unit of Alaska North Slope, implying that the extension of the crust beneath the western Canada Basin occurred no later than the Middle Jurassic. Super-Au strata (~16 km) onlap the condensed section, SDRs, growth and passive margin strata from west to east, tapering down to a few kilometers north and eastward across the seismic grid. These are part of the Aptian through Cenozoic Brookian megasequence, a series of clinothems, deposited across the foreland of the Chukotka and Brooks Range orogens. These strata were deposited by northward-migrating depositional systems that progressively filled the North Chukchi Basin and buried the southern flank of the Chukchi Borderland, and deposited along the Northwind margin of the Canada Basin. Another unit of growth strata is observed in the Northwind Basin, indicating another phase of extension of the Boderland. The Upper Cretaceous section of the Brookian megasequence is displaced by normal faults over the Chukchi Plateau and inferred age-equivalent strata over the Northwind Ridge. These constrain the second phase of extension of the interior Borderland to the Late Cretaceous to Paleocene. The recognition of the sub-Au units and continuity of the super-Au units across the area, north-striking normal faults, and the absence of east-directed thrust faults between the Northwind Ridge and Canada Basin invalidate one model proposed for tectonic development of the Amerasia Basin. Models that require significant relative motion between the Chukchi Shelf and Borderland since the Middle Jurassic are precluded by these observations.National Science Foundation Award OPP-0909568, ExxonMobi

    Mobil pazarlama: Turizmde artırılmış gerçeklik kullanımı

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    The developing number of applications by smart devices provides an expanding diversity of travel-related services. In the most recent decade, marketers and advertisers have developed more innovative practices to attract consumers. One of these new marketing tools is augmented reality (AR) application with the smart technologies, which is considered as an advertising and new marketing communication instrument that increases awareness and helps get information. The use of augmented reality has unfolded across several sectors in recent years. One in every of the areas of wherever this technology will notice a possible use is that the tourism industry. AR is taken into account extremely vital for promoting in several industries; but, within the tourism industry there exist comparatively few researches and articles despite the very fact that tourism may fine benefit from the applications for these practices. Therefore this study aimed to seeks; 1) To identify the potentials of the AR applications within the tourism industry. 2) To identify the AR applications in several tourism businesses at the tourism industry from the attitude of promoting, for instance hotels, restaurants, museums and transportation.Akıllı cihazlarla uygulanan çok sayıda uygulama seyahatle ilgili hizmetlerde genişleyen bir çeşitlilik sunmaktadır. Son on yılda, pazarlamacılar ve reklamcılar müşterileri çekmek için daha yenilikçi uygulamalar geliştirmişlerdir. Bu yeni pazarlama araçlarından biri farkındalığı artıran ve bilgi edinmede yardımcı olan, yeni bir reklam aracı ve pazarlama iletişimi aracı olarak kabul edilen, akıllı teknolojiler ile uygulanan artırılmış gerçeklik (AG) uygulamalarıdır. Artırılmış gerçeklik kullanımına son yıllarda birçok sektörlerde tanıklık uygulamalarıdır. Artırılmış gerçeklik kullanımına son yıllarda birçok sektörlerde tanıklık edilmektedir. Bu teknolojinin kullanımına imkân sağlayan alanlardan biride turizm sektörüdür. AG çeşitli sektörlerde pazarlamada hayati öneme sahiptir ancak, turizm sektöründe bu uygulamalara yönelik çok az sayıda araştırma ve makale bulunmaktadır. Bu sebeple bu araştırma: 1) Turizm sektöründe AG uygulamalarının potansiyelini tanımlamayı, 2) Oteller, restoranlar, müzeler, ulaşım gibi çeşitli turizm sektörlerinde pazarlamada kullanılan AG uygulamalarını incelemeyi amaçlamıştır

    Mineral element distribution of cotton (Gossypium hirsutum L.) seedlings under different salinity levels

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    Cotton (Gossypium hirsutum L.) is the world's leading natural fiber and second largest oilseed crop. In addition to textile manufacturing, cotton and cotton-by products are the sources of wealth of consumer based products, livestock feed, fertilizer, foodstuff and paper. High concentrations of NaCl in soils account for large decreases in the yield of a wide variety of crops all over the world. The present study was conducted to evaluate NaCl stress on mineral nutrient composition of cotton due to its economic importance. Cotton seeds were germinated in Magenta vessels containing Murshige and Skoog (MS) media for 15 days and then transferred in sterile jars containing MS exposed to different levels of NaCl (50, 100, 200 and 400 mM) treatments for 1 month. Uptake of some mineral nutrients (B, Ca, Fe, K, Mg, Mn, Na and Zn) by the plants was examined in roots and leaves by using an Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES). The data proved that plant growth and uptake and accumulation of microelements are altered extensively in cotton grown with NaCl. Excess NaCl reduces the uptake pattern of certain elements and increases that of others, the patterns depending on the element and the plant part being compared to the control.Marmara University, Commission of Scientific Research Project under grant FEN-A-030108-001

    Determination of some heavy metals and mineral nutrients of bay tree (Laurus nobilis L.) in Bartin city, Turkey

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    Concentrations of Al, Cd, Cu, Ni, and Pb in Laurus nobilis L. were examined for assessment of the impact of heavy metal exposure during winter periods, since these metals have the highest toxic potential. In this study, leaf (washed and unwashed), bark and branch samples of L. nobilis and soil samples were collected from 13 different localities, belonged to three stations. In conjunction with analyzing impact of the heavy metal exposure on the city using L. nobilis as a biomonitoring tool, the uptake and composition of mineral nutrients of L. nobilis were also investigated for determining the effects of heavy metals on mineral nutrition metabolism of the plant. The heavy metal and mineral nutrient concentrations of the collected samples were measured by using ICP-OES. The obtained data was analyzed with SPSS statistics program. As a result of measurements, the lowest and highest heavy metal accumulations and the amount of mineral nutrients measured in plants were as follows; Al (14.69-122.44 mg/kg d. wt), Cd (0.23-0.89 mg/kg d. wt), Cu (1.64-14.25 mg/kg d. wt.), Ni (0.001-0.45 mg/kg d. wt.), Pb (2.06-5.28 mg/kg d. wt.) and B (1.04- 6.67 mg/kg d. wt.), Ca (1195.34-4919.03 mg/kg d. wt.), Fe (17.13-203.25 mg/kg d. wt.), K (538.99-3778.37 mg/kg d. wt.), Mg(48.1-268.5 mg/kg d. wt.), Na (24.91-77.43 mg/kg d. wt.) and Zn (4.75-15.74 mg/kg d. wt.). According to the experimental data, the volume of the air pollution was analyzed and found significant in the city. Also, it was noticed that the metabolism of mineral nutrients of L. nobilis was altered by heavy metals. Finally, it was proved that L. nobilis is a suitable organism to be used as a biomonitoring tool for conducting research on heavy metal pollution

    AIR FLOW ANALYSIS AROUND THE AUTOGYRO FUSELAGE

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    The paper presents the results of the simulation of the air flow around the gyroplane without the influence of the rotor and pusher propellers. Three-dimensional calculations were performed using ANSYS Fluent software. Based on the calculations, the values of the drag force and the lift force on each component of the rotorcraft were determined. Based on the results obtained, the effect of angle of attack on the aerodynamic forces was obtained
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