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41.
Underground coal mining activities in Kozlu Hard Coal Basin have reached a level affecting ground layers inside the mining seams and the surface just above the mining operations, causing movements in vicinity of the basin. The movements emerge as collapsing in vertical direction and as sliding, curling and bending in horizontal direction and are termed mining subsidence since they exhibit themselves in ground layers and on earth surfaces in mining environments. These mining-induced movements cause damages and destructions on structures inside and on the surface of mining grounds, and the dimensions of these damages depend upon quality of structures and magnitude of movements. In order to contribute toward a solution to these problems and to mitigate the effects arising during and after mining activities, one should identify and investigate damage prone movements and determine the movement–time relationship. Therefore, it is immensely important to observe, investigate, and measure these movements in regions where mining activities take place. This study focuses on the surface movement-related deformations on the engineering structures in the basin such as Kozlu Seaport and some part of the Zonguldak-Kozlu Road. For this reason, subsidence monitoring points were established on the engineering structures in the basin in a geodetic network concept, and three periods of precise leveling and static GPS observations were conducted. Analyzing these two types of geodetic observations, active and residual subsidence effects were determined for both Kozlu Seaport and the Road nearby. 相似文献
42.
Cenk Yalt?rak Umut B. ülgen Cengiz Zabc? Sven Oliver Franz Sena Ak?er ?n Mehmet Sak?n? M. Nam?k ?a?atay Bedri Alpar Kurultay ?ztürk Cemal Tuno?lu Selma ünlü 《Geo-Marine Letters》2012,32(3):267-274
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?C86 (2011) doi:10.1007/s00367-010-0216-9) suggest the possibility of two alternative waterway connections via lakes Sapanca and ?znik. Their Black Sea to Sea of Marmara multi-connection hypothesis, which is based on undated marine fossils collected in both lakes from surficial grab samples, conflicts with many earlier studies. In this contribution, the hypothesis and the underlying data are discussed in the light of previous tectonic, sedimentological and limnological findings showing that it is impossible to have had marine connections through lakes Sapanca and ?znik during the last 11.5?ka. Global sea-level trends and tectonic uplift rates would accommodate a connection between the Sea of Marmara and Lake ?znik in the middle Pleistocene. Uplift rates for the northern block of the North Anatolian Fault, when compared with the global sea-level curve, clearly indicate that there cannot have been a connection through the ?zmit Gulf?CLake Sapanca?CSakarya Valley for at least the past 500?ka. Moreover, borehole sediments along the western shores of Lake Sapanca, which reach down to the bedrock, do not contain any marine fossils. 相似文献
43.
S. Bilir S. Ak S. Karaali A. Cabrera-Lavers T. S. Chonis C. M. Gaskell † 《Monthly notices of the Royal Astronomical Society》2008,384(3):1178-1188
We present colour transformations for the conversion of the Two Micron All Sky Survey (2MASS) photometric system to the Johnson–Cousins UBVRI system and further into the Sloan Digital Sky Survey (SDSS) ugriz system. We have taken SDSS gri magnitudes of stars measured with the 2.5-m telescope from SDSS Data Release 5 (DR5), and BVRI and JHK s magnitudes from Stetson's catalogue and Cutri et al., respectively. We matched thousands of stars in the three photometric systems by their coordinates and obtained a homogeneous sample of 825 stars by the following constraints, which are not used in previous transformations: (1) the data are dereddened, (2) giants are omitted and (3) the sample stars selected are of the highest quality. We give metallicity, population type and transformations dependent on two colours. The transformations provide absolute magnitude and distance determinations which can be used in space density evaluations at short distances where some or all of the SDSS ugriz magnitudes are saturated. The combination of these densities with those evaluated at larger distances using SDSS ugriz photometry will supply accurate Galactic model parameters, particularly the local space densities for each population. 相似文献
44.
S. Bilir S. Karaali S. Ak K. B. Cokunolu E. Yaz A. Cabrera-Lavers 《Monthly notices of the Royal Astronomical Society》2009,396(3):1589-1595
We present a new luminosity–colour relation based on trigonometric parallaxes for thin-disc main-sequence stars in Sloan Digital Sky Survey (SDSS) photometry. We matched stars from the newly reduced Hipparcos catalogue with the ones taken from Two-Micron All-Sky Survey (2MASS) All-Sky Catalogue of Point Sources, and applied a series of constraints, i.e. relative parallax errors (σπ /π≤ 0.05) , metallicity (−0.30 ≤[M/H]≤ 0.20 dex) , age (0 ≤ t ≤ 10 Gyr) and surface gravity (log g > 4) , and obtained a sample of thin-disc main-sequence stars. Then, we used our previous transformation equations ( Bilir et al. 2008a ) between SDSS and 2MASS photometries and calibrated the Mg absolute magnitudes to the ( g − r )0 and ( r − i )0 colours. The transformation formulae between 2MASS and SDSS photometries along with the absolute magnitude calibration provide space densities for bright stars which saturate the SDSS magnitudes. 相似文献
45.
İrem Elitez Cenk Yaltırak Akın Kürçer Ersin Özdemir Çağıl Uygun Güldoğan 《Geodinamica Acta》2017,29(1):91-102
The Kibyra Fault is considered as the most significant evidence about the existence of the NE–SW-striking left-lateral Burdur-Fethiye Fault Zone in the south-western Anatolia in previous studies. However, recent studies show that there is a shear regime, named the Burdur-Fethiye Shear Zone, dominated by normal and left-lateral oblique normal faults in this region. A large number of ancient cities lie on this zone and many of them have been damaged by ancient earthquakes. One of these ancient cities is the ancient city of Kibyra. Most of previous studies suggest the Kibyra Fault depending on the damage in the city. However, the closest fault is located on the western side of the city and the earthquake damage was most likely caused by ground shaking. In this study, the existence of the supposed Kibyra Fault is discussed by integrating field studies, geological maps, trench data, digital elevation model and geomorphological analysis. In conclusion, it is understood that there is no evidence directly indicating a 35-km-long left-lateral fault in this region. The aim of this study is to examine the existence of the Kibyra Fault, take a different approach to the active fault studies and emphasise the importance of active faults for socio-economic conditions. 相似文献
46.
Oya Ankaya Pamukçu Zafer Akçığ Şevket Demirbaş Ekrem Zor 《Pure and Applied Geophysics》2007,164(11):2345-2358
The tectonic regime of Eastern Anatolia is determined by the Arabia-Eurasia continent-continent collision. Several dynamic
models have been proposed to characterize the collision zone and its geodynamic structure. In this study, change in crustal
thickness has been investigated using gravity, magnetic and topographic data of the region. In the first stage, two-dimensional
low-pass filter and upward analytical continuation techniques were applied to the Bouguer gravity data of the region to investigate
the behavior of the regional gravity anomalies. Next the moving window power spectrum method was used, and changes in the
probable structural depths from 38 to 52 km were determined. The changes in crustal thickness where free air gravity and magnetic
data have inversely correlated and the type of the anomaly resources were investigated applying the Euler deconvolution method
to Bouguer gravity data. The obtained depth values are consistent with the results obtained using the power spectrum method.
It was determined that the types of anomaly resources are different in the west and east of the 40° E longitude. Finally,
using the obtained findings from this study and seismic velocity models proposed for this region by previous studies, a probable
two-dimensional crust model was constituted. 相似文献
47.
Bedrock bedding,landsliding and erosional budgets in the Central European Alps 总被引:4,自引:0,他引:4
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Fábio Cruz Nunes Romain Delunel Fritz Schlunegger Naki Akçar Peter W. Kubik 《地学学报》2015,27(5):370-378
We explore the controls of the litho‐tectonic architecture on the erosional flux in the 370‐km2 Glogn basin (European Alps). In this basin, the bedding and schistosity of the bedrock dip parallel to the topographic slope on the NW valley flank, leading to a non‐dip slope situation on the opposite SE valley side. While the dip slope condition has promoted the occurrence of landslides (e.g. the c. 30‐km2 deep‐seated Lumnezia landslide), the opposite non‐dip slope side of the valley hosts >100‐m‐deeply incised tributary streams. 10Be concentrations of stream sediments yield catchment‐averaged denudation rates that vary between 0.27 ± 0.03 and 2.19 ± 0.37 mm a?1, while the spatially averaged denudation rate of the entire basin is 1.99 ± 0.34 mm a?1. Our 10Be‐based approach reveals that the Lumnezia landslide front contributes c. 30–65% of the entire sediment budget, although it covers <5% of the Glogn basin. This suggests a primary control of the bedrock bedding on erosion rates and processes. 相似文献
48.
Camille Litty Fritz Schlunegger Naki Akçar Pierre Lanari Marcus Christl Christof Vockenhuber 《地球表面变化过程与地形》2019,44(5):991-1003
Sediment accumulation can occur in response to a change in either tectonic or climatic driving forces. Here, we explore these controls on the deposition of the Lima Conglomerate, Peru. We use a combination of quantitative methods to explore the age of sediment accumulation, the provenance of the material and the paleo-erosion rates recorded by these deposits. Isochron burial dating with cosmogenic 10Be and 26Al yield an age of c. 500 ka for the base (490 ± 70 ka) and the uppermost sample situated c. 30 m higher upsection (490 ± 80 ka). Results of paleo-erosion rate estimates with concentrations of in situ 10Be show a c. 60% increase from 105 ± 10 mm ka-1 for the base to 169 ± 14 mm ka-1 for the uppermost sample. Finally, provenance tracing with in situ U/Pb ages on detrital zircon implies that the material has been derived from the entire drainage basin. The combination of results suggests that sediment accumulation occurred in response to an erosional pulse, which affected the entire basin within a short time interval. Because 10Be data represents a large spatial record of erosion, we exclude the possibility where a breakout of a lake or a focused release of material in response to earthquakes, were responsible for the large material flux. Instead, the erosional pulse was likely to have occurred at the scale of the entire basin, supporting the idea of a larger-scale, most likely climate driven control. In this context, the accumulation age of c. 500 ka falls into an orbital cycle fostering the emerging picture in the literature that sediment routing in the Andes have most likely been driven by climate and cyclic changes. We suggest that the Andean mountain range offers an ideal laboratory to explore the erosional history in relation to climate patterns, at least in Peru. © 2018 John Wiley & Sons, Ltd. 相似文献
49.
Z. F. Bostancı T. Yontan S. Bilir T. Ak T. Güver S. Ak E. Paunzen Ç. S. Başaran E. Vurgun B. A. Akti M. Çelebi H. Ürgüp 《Astrophysics and Space Science》2018,363(7):143
In this study, we present CCD UBV photometry of poorly studied open star clusters, Dolidze 36, NGC 6728, NGC 6800, NGC 7209, and Platais 1, located in the first and second Galactic quadrants. Observations were obtained with T100, the 1-m telescope of the TÜB?TAK National Observatory. Using photometric data, we determined several astrophysical parameters such as reddening, distance, metallicity and ages and from them, initial mass functions, integrated magnitudes and colours. We took into account the proper motions of the observed stars to calculate the membership probabilities. The colour excesses and metallicities were determined independently using two-colour diagrams. After obtaining the colour excesses of the clusters Dolidze 36, NGC 6728, NGC 6800, NGC 7209, and Platais 1 as \(0.19\pm0.06\), \(0.15\pm0.05\), \(0.32\pm0.05\), \(0.12\pm 0.04\), and \(0.43\pm0.06\) mag, respectively, the metallicities are found to be \(0.00\pm0.09\), \(0.02\pm0.11\), \(0.03\pm0.07\), \(0.01\pm0.08\), and \(0.01\pm0.08\) dex, respectively. Furthermore, using these parameters, distance moduli and age of the clusters were also calculated from colour-magnitude diagrams simultaneously using PARSEC theoretical models. The distances to the clusters Dolidze 36, NGC 6728, NGC 6800, NGC 7209, and Platais 1 are \(1050\pm90\), \(1610\pm190\), \(1210\pm150\), \(1060\pm90\), and \(1710\pm250\) pc, respectively, while corresponding ages are \(400\pm100\), \(750\pm150\), \(400\pm100\), \(600\pm100\), and \(175\pm50\) Myr, respectively. Our results are compatible with those found in previous studies. The mass function of each cluster is derived. The slopes of the mass functions of the open clusters range from 1.31 to 1.58, which are in agreement with Salpeter’s initial mass function. We also found integrated absolute magnitudes varying from ?4.08 to ?3.40 for the clusters. 相似文献
50.
A. N. Semena M. G. Revnivtsev I. M. Khamitov R. A. Burenin T. Ak Z. Eker M. N. Pavlinsky 《Astronomy Letters》2013,39(4):227-236
The properties of the hot zone in the accretion flow near the surface of a magnetized white dwarf have been studied. For this purpose, the aperiodic optical variability of LS Peg, one of the brightest intermediate polars in the northern sky, has been investigated. The main radiation of the hot zone, which is then reemitted in the optical band, results from the radiation of an optically thin plasma heated during the passage of the accretion flow of a standing shock. Recently, Semena and Revnivtsev (2012) have shown that the aperiodic variability (flickering) of accreting magnetized white dwarfs should have a characteristic feature in the range of Fourier frequencies corresponding to the plasma cooling time in this hot region. The photometric brightness measurements for LS Peg made with the RTT-150 telescope using a high-speed ANDOR iXon CCD array have allowed the break frequency in the power spectrum of the source’s variability to be constrained. Constraints on the geometry of the accretion column for the white dwarf in LS Peg and on the plasma parameters in it have been obtained. 相似文献