Paleomagnetic results from Northeast Anatolia: remagnetization in Late Cretaceous sandstones and tectonic rotation at the Eastern extension of the Izmir–Ankara–Erzincan suture zone     

Mualla Cengiz Çinku 《Acta Geophysica》2017,65(6):1095-1109

Paleomagnetic results obtained from Upper Cretaceous sandstones in Northeastern Anatolia demonstrate that the entire area from Erzincan to Kars has been remagnetised. The remagnetisation was acquired before the Middle Eocene collision between the Eastern Pontides and the Arabian Platform because Middle Eocene sandstones carry primary natural remanent magnetisations. The post-folding in situ mean direction of the Upper Cretaceous sandstones is compared with mean directions of younger, Middle Eocene to present rock formations. As a result, a two-stage antagonistic rotation mechanism is proposed. First, the collision between the Pontides and the Taurides between Late Cretaceous and Middle Eocene was associated by clockwise rotation of  ~ 26°. In the second stage between Middle Eocene and Middle Miocene and beyond, counterclockwise rotations up to ~ 52° of the Pontide and Anatolide blocks and clockwise rotations of the Van Block were characterised by regional shortening and westward escape.  相似文献   

The impact of water resources development projects on water vapor pressure trends in a semi-arid region, Turkey     

Tahsin Tonkaz  Mahmut Çetin  Kâzım Tülücü 《Climatic change》2007,82(1-2):195-209

The aim of this study was to investigate long-term seasonal trends and decadal change patterns of monthly mean water vapor pressure (WVP) observation series at 16 meteorological stations scattered point-wisely over the Southeastern Anatolian Project (GAP) area in Turkey, where large-scale soil and water development projects have been put into practice since the 1970s. The record length of WVP observation series of each station varied between 31- and 41-years between 1962 and 2002. The monthly mean WVP observation series of each station was rearranged on seasonal basis. Sequential Mann–Kendall trend test, Sen’s slope estimator, and Spearman’s rank–order correlation tests were employed for detection of likely trends, and Kruskall–Wallis test was used to detect decadal variations in WVP series of each observation station. A possible area of representation for each meteorological station was determined by using the Thiessen polygons technique in a geographical information systems media. It was found that 15 seasonal WVP series have a positive trend covering 97% of the GAP area in the summer season; although one WVP series has a negative trend direction. However, in the spring season, 33% of the area had a positive trend, and a negative trend did not appear in any stations. WVP records in the winter season showed an increasing trend over 19% of the GAP area, whereas a decreasing trend prevailed in 9% of the area. The study results led us to conclude that the substantial increase of WVP observations in summer season could be attributed to both the shift from rain-fed agriculture to irrigated agriculture being made increasingly spacious year by year and building large water reservoirs in the GAP located in a semi-arid region. The results also indirectly suggested that the historical trends in the WVP parameters might be related to global climate change phenomenon.  相似文献   

Stability Assessment of the Gökgöl Karstic Cave (Zonguldak,Turkey) by Analytical and Numerical Methods     

Melih Geniş  Berdan Çolak 《Rock Mechanics and Rock Engineering》2015,48(6):2383-2403

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On‐line Solid Phase Extraction of Copper in Water Samples with Flow Injection Flame Atomic Absorption Spectrometry     

Tülin Çetin  Ahmet Ülgen  Şerife Tokalıoğlu 《洁净——土壤、空气、水》2011,39(3):244-249

An on‐line solid phase extraction method for the preconcentration and determination of Cu(II) by flame atomic absorption spectrometry has been described. The procedure is based on the retention of Cu(II) ions at pH 6.0 on a minicolumn packed with Amberlite XAD‐1180 resin impregnated with chrome azurol S. After preconcentration, Cu(II) ions adsorbed on the impregnated resin were eluted by 1 mol L^?1 HNO₃ solution. Several parameters, such as pH, type of eluent, flow rates of sample and eluent solutions, amount of resin were evaluated. At optimized conditions, for 3.5 min of preconcentration time, the system achieved a detection limit of 1.0 µg L^?1, and a relative standard deviation of 1.2% at 0.2 µg mL^?1 copper. An enrichment factor of 56‐fold was obtained with respect to the copper determination. The proposed method was successfully validated by the analysis of standard reference material (TMDA 54.4 lake water) and recovery studies. The method was applied to the preconcentration of Cu(II) in natural water samples.  相似文献   

Structure and recent evolution of the Hazar Basin: a strike‐slip basin on the East Anatolian Fault,Eastern Turkey     

D. Garcia Moreno  A. Hubert‐Ferrari  J. Moernaut  J. G. Fraser  X. Boes  M. Van Daele  U. Avsar  N. Çağatay  M. De Batist 《Basin Research》2011,23(2):191-207

The Hazar Basin is a 25 km‐long, 7 km‐wide and 216 m‐deep depression located on the central section of the East Anatolian Fault zone (eastern Turkey) and predominantly overlain by Lake Hazar. This basin has been described previously as a pull‐apart basin because of its rhombic shape and an apparent fault step‐over between the main fault traces situated at the southwestern and northeastern ends of the lake. However, detailed structural investigation beneath Lake Hazar has not been undertaken previously to verify this interpretation. Geophysical and sedimentological data from Lake Hazar were collected during field campaigns in 2006 and 2007. The analysis of this data reveals that the main strand of the East Anatolian Fault (the Master Fault) is continuous across the Hazar Basin, connecting the two segments previously assumed to be the sidewall faults of a pull‐apart structure. In the northeastern part of the lake, an asymmetrical subsiding sub‐basin, bounded by two major faults, is cross‐cut by the Master Fault, which forms a releasing bend within the lake. Comparison of the structure revealed by this study with analogue models produced for transtensional step‐overs suggests that the Hazar Basin structure represents a highly evolved pull‐apart basin, to the extent that the previous asperity has been bypassed by a linking fault. The absence of a step‐over structure at the Hazar Basin means that no significant segmentation boundary is recognised on the East Anatolian Fault between Palu and Sincik. Therefore, this fault segment is capable of causing larger earthquakes than recognised previously.  相似文献   

E1 and E2 transitions for Fe XVI,Co XVII and Ni XVIII     

G. Çelik  Ş. Ateş 《Astrophysics and Space Science》2016,361(7):229

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Non-existence of Brans-Dicke theory in higher dimensional FRW universe     

Halife Çaǧlar  Sezgin Aygün 《Astrophysics and Space Science》2016,361(6):200

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Estimation of the soil strength parameters in Tertiary volcanic regolith (NE Turkey) using analytical hierarchy process     

Hakan Ersoy  Melek Betül Karsli  Seda Çellek  Bilgehan Kul  İdris Baykan  Robert L Parsons 《Journal of Earth System Science》2013,122(6):1545-1555

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City of Bingöl in May 2003: Assessment of strong ground motion records     

U Çeken  G Beyhan  H H Selim 《Journal of Earth System Science》2014,123(2):381-394

The main shock of Bingöl earthquake (M _W = 6.4) recorded by six accelerometers in the area occurred at 03:27 local time on May 1, 2003. The largest acceleration value of north–south component was recorded as 545.5 cm/s² at the nearest station which it is 12 km away from the epicenter of earthquake. Especially, 0.15 s short period was observed when high spectral acceleration value occurred. An acceleration value greater than 50 gal was recorded at the BNG (Bingöl) station and structural damage occurred within 6.5 s was very important for the near source and strong ground motion seismology. The recorded peak acceleration values were greater than the estimated empirical acceleration values. However, the structural damage was not as high and widespread as expected. This occurrence was explained by considering the factors of earthquake source, frequency content, effective duration, effective acceleration value, local soil conditions, rupture direction and attenuation.  相似文献   

Period studies of classical Algol-type binaries II: UX Leo,RW Mon,EQ Ori,XZ UMa and AX Vul     

F. Soydugan  A. Erdem  S.S. Doğru  F. Aliçavuş  E. Soydugan  C. Çiçek  O. Demircan 《New Astronomy》2011,16(4):253-264

This study presents an investigation of the orbital period variations of five Algol type binaries, UX Leo, RW Mon, EQ Ori, XZ UMa and AX Vul based on all available minima times. The O–C diagrams of all systems exhibit a periodic variation superimposed on a downward parabolic segment. The mass loss due to magnetic braking effect in the cooler components is assumed to account for the parabolic variation with a downward shape, while it is suggested that the light-time effect (LITE) due to an unseen component around the eclipsing binaries explains the tilted sinusoidal changes in their O–C diagrams. The orbital period decrease rates for the systems are estimated as approximately between about 0.7 and 2.5 s per century. It is clearly seen that mass loss effect is more dominant than the expected mass transfer for classical Algols in this study. The minimum mass of the probable third bodies around the eclipsing pairs was calculated to be ?0.5 M_⊙ except for UX Leo, in which it was estimated to be approximately 0.9 M_⊙. In order to search for third lights in the light curves of five systems, the V-light curves of the systems were analyzed and their physical and photometric parameters were determined. For UX Leo, a significant third light contribution was determined. We found a very small third light that can be tested using multi-color light curves, for RW Mon, EQ Ori and XZ UMa, while a third light for AX Vul could not be exposed.  相似文献