The Palaeo-Tethyan suture: A line of demarcation between two fundamentally different architectural styles in the structure of Asia   总被引：5，自引：0，他引：5  

Ali Mehmet  Celal &#;engör 《Island Arc》1992,1(1):78-91

Abstract The Palaeo-Tethyan suture separates regions characterized by two fundamentally different tectonic styles in the structure of the Tethysides. North of the suture in Iran, Turkmenistan, Afghanistan, Tadjikistan, Kirgizstan, Uzbekistan, Kazakhstan and large parts of the Russian Federation and China, orogenic development is characterized by very large subduction-accretion complexes developed since the late Proterozoic. Magmatic arc axes migrated radially outwards from the 'Old Vertex of Eurasia' and consolidated the accretionary prisms into a 'basement complex' dominated by a pelitic composition. In such orogens, called the 'Turkic-type' after the dominant ethnic population of Central Asia, ophiolites are unreliable indicators of sutures, because they are present throughout the 'basement' as in-faulted shreds and rarely as nappes. By contrast, south of the Palaeo-Tethyan suture, orogeny was commonly characterized by a Sumatra- or Andean-type continental margin arc (e.g. the Transhimalaya arc) that in places became an island arc by back-arc basin rifting (e.g. the Black Sea behind the Rhodope-Pontide fragment) and later collided with an Atlantic- (as in the Himalaya) or California-type (as in the Alps) continental margin to create Alpine- or Himalayan-type orogenic belts. Turkic-type orogenic belts result from the exaggeration of the Himalayan-type as a result of the subduction of very large oceanic areas that contain great amounts of sediment. They contribute to the enlargement and also possibly the growth of the continental crust which has a composition more silicic than basalt. The Palaeo-Tethyan suture is thus a line across which the rate of continental enlargement by subduction-accretion changed dramatically.  相似文献   

Hydrochemical characterization of Pamukkale travertines,Denizli, Turkey,for remediative measures   总被引：1，自引：0，他引：1  

Sukran Acikel  Mehmet Ekmekci 《Environmental Earth Sciences》2016,75(22):1456

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Error Propagation in Isometric Log-ratio Coordinates for Compositional Data: Theoretical and Practical Considerations     

Mehmet Can Mert  Peter Filzmoser  Karel Hron 《Mathematical Geosciences》2016,48(8):941-961

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Projected changes to winter temperature characteristics over Canada based on an RCM ensemble     

Dae Il Jeong  Laxmi Sushama  Gulilat Tefera Diro  M. Naveed Khaliq 《Climate Dynamics》2016,46(5-6):1351-1369

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Variations in the abundance of fisheries resources and ecosystem structure in the Japan/East Sea   总被引：1，自引：0，他引：1  

Chang Ik Zhang  Jae Bong Lee  Young Il Seo  Sang Cheol Yoon  Suam Kim 《Progress in Oceanography》2004,61(2-4):245

Evidence supports the hypothesis that two climatic regime shifts in the North Pacific and the Japan/East Sea, have affected the dynamics of the marine ecosystem and fisheries resources from 1960 to 2000. Changes in both mixed layer depth (MLD) and primary production were detected in the Japan/East Sea after 1976. The 1976 regime shift appears to have caused the biomass replacement with changes in catch production of major exploited fisheries resources, including Pacific saury, Pacific sardine and filefish. Both fisheries yield and fish distribution are reflected in these decadal fluctuations. In the 1960s and 1990s, common squid dominated the catches whereas in the 1970s and 1980s, it was replaced by walleye pollock. In the post-1988 regime shift, the distribution of horse mackerel shifted westward and southward and its distributional overlap with common mackerel decreased. The habitat of Pacific sardine also shifted away from mackerel habitats during this period. To evaluate changes in the organization and structure of the ecosystem in the Japan/East Sea, a mass-balanced model, Ecopath, was employed. Based on two mass-balanced models, representing before (1970–75) and after (1978–84) the 1976 regime shift, the weighted mean trophic level of catch increased from 3.09 before to 3.28 after. Total biomass of species groups in the Japan/East Sea ecosystem increased by 15% and total catch production increased by 48% due to the 1976 regime shift. The largest changes occurred at mid-trophic levels, occupied by fishes and cephalopods. The dominant predatory species shifted from cephalopods to walleye pollock due to the 1976 regime shift. It is concluded that the climatic regime shifts caused changes in the structure of the ecosystem and the roles of major species, as well as, large variations in biomass and production of fisheries resources.  相似文献   

The stratigraphic evolution of the Indus Fan and the history of sedimentation in the Arabian Sea   总被引：6，自引：1，他引：6  

Clift  Peter  Gaedicke  Christoph  Edwards  Rosemary  Il Lee  Jae  Hildebrand  Peter  Amjad  Shahid  White  Robert S.  Schlüter  Hans-Ulrich 《Marine Geophysical Researches》2002,23(3):223-245

The Indus Fan records the erosion of the western Himalayas and Karakoram since India began to collide with Asia during the Eocene, 50 Ma. Multi-channel seismic reflection data from the northern Arabian Sea correlated to industrial well Indus Marine A-1 on the Pakistan Shelf show that sedimentation patterns are variable through time, reflecting preferential sedimentation in deep water during periods of lower sea-level (e.g., middle Miocene, Pleistocene), the diversion of sediment toward the east following uplift of the Murray Ridge, and the autocyclic switching of fan lobes. Individual channel-levee systems are estimated to have been constructed over periods of 10⁵–10⁶ yr during the Late Miocene. Sediment velocities derived from sonobuoys and multi-channel stacking velocities allow sections to be time-depth converted and then backstripped to calculate sediment budgets through time. The middle Miocene is the period of most rapid accumulation, probably reflecting surface uplift in the source regions and strengthening of the monsoon at that time. Increasing sedimentation during the Pleistocene, after a late Miocene-Pliocene minimum, is apparently caused by faster erosion during intense glaciation. The sediment-unloaded geometry of the basement under the Pakistan Shelf shows a steep gradient, similar to the continent-ocean transition seen at other rifted volcanic margins, with basement depths on the oceanward side indistinguishable from oceanic crust. Consequently we suggest that the continent-ocean transition is located close to the present shelf break, rather than >350 km to the south, as previously proposed.  相似文献   

Evaluation of typhoon‐induced rainfall using nonparametric Monte Carlo simulation and locally weighted polynomial regression     

Tae‐Suk Oh  Young‐Il Moon  Hyun‐Han Kwon 《水文研究》2011,25(11):1765-1777

Typhoons in Korea are the major causes of natural disasters in the Korean peninsula. In this study, rainfall generated by typhoons was quantitatively analysed using various statistical methods. First, the frequency analysis of rainfall induced by typhoons was carried out to calculate the design rainfall. Second, the frequency analysis of simulated rainfall derived by nonparametric Monte Carlo simulation (NMCS) was performed to evaluate the uncertainty of rainfall caused by typhoons. Third, the regression relationship between the physical characteristic factors of typhoons and rainfall was established by locally weighted polynomial regression (LWPR), and the characteristic factors of typhoons were simulated. The simulated characteristic factors were then used to estimate rainfall and to calculate the design rainfall by typhoons. Comparative analyses of design rainfalls as estimated using various statistical methods were performed. The LWPR showed good performance in terms of reproducing typhoon characteristics. Therefore, the combined NMCS and LWPR method suggested in this study can be used as a supplementary technique for assessing extreme rainfall with climate change and reflected variability. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

Seasonal and spatial variations in the scaling and correlation structure of streamflow data     

Mehmet Özger  Ashok K. Mishra  Vijay P. Singh 《水文研究》2013,27(12):1681-1690

Seasonal and spatial variability in scaling, correlation and wavelet variance parameter of daily streamflow data were investigated using 56 gauging stations from five basins located in two different climate zones. Multifractal temporal scaling properties were detected using a multiplicative cascade model. The wavelet variance parameter yielded persistence properties of the streamflow time series. Seasonal variations were found to be significant in that winter and spring seasons where large‐scale frontal events are dominant showed higher long‐term correlations and less multifractality than did summer and fall seasons. Coherent spatial variations were apparent. The Neches River basin located in a subtropic humid climate zone exhibited high persistence and long‐term correlation as well as less multifractality as compared with other basins. It is found that larger drainage areas tend to have smaller multifractality and higher persistence structure, and this tendency becomes apparent in regions that receive large amounts of precipitation and decreases towards arid regions. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

The value of updating ensemble streamflow prediction in reservoir operations     

Hyung‐Il Eum  Young‐Oh Kim 《水文研究》2010,24(20):2888-2899

This study proposes a new monthly ensemble streamflow prediction (ESP) forecasting system that can update the ESP in the middle of a month to reflect the meteorological and hydrological variations during that month. The reservoir operating policies derived from a sampling stochastic dynamic programming model using ESP scenarios updated three times a month were applied to the Geum River basin to measure the value of updated ESP for 21 years with 100 initial storage combinations. The results clearly demonstrate that updating the ESP scenario improves the accuracy of the forecasts and consequently their operational benefit. This study also proves that the accuracy of the ESP scenario, particularly when high flows occur, has a considerable effect on the reservoir operations. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

Identification of appropriate lags and temporal resolutions for low flow indicators in the River Rhine to forecast low flows with different lead times     

Mehmet C. Demirel  Martijn J. Booij  Arjen Y. Hoekstra 《水文研究》2013,27(19):2742-2758

The aim of this paper is to assess the relative importance of low flow indicators for the River Rhine and to identify their appropriate temporal lag and resolution. This is done in the context of low flow forecasting with lead times of 14 and 90 days. First, the Rhine basin is subdivided into seven sub‐basins. By considering the dominant processes in the sub‐basins, five low flow indicators were selected: precipitation, potential evapotranspiration, groundwater storage, snow storage and lake storage. Correlation analysis was then carried out to determine the relationship between observed low flows and preselected indicators with varying lags (days) and temporal resolutions (from 1 day to 7 months). The results show that the most important low flow indicators in the Alpine sub‐basins for forecasts with a lead time of 14 days are potential evapotranspiration with a large lag and temporal resolution, and lake levels with a small lag and temporal resolution. In the other sub‐basins groundwater levels with a small lag and temporal resolution are important in addition to potential evapotranspiration with a large lag and temporal resolution. The picture is slightly different for forecasts with a lead time of 90 days. The snow storage in the Alpine sub‐basins and the precipitation in the other sub‐basins also become relevant for low flows. Consequently, the most important low flow indicators in the Alpine sub‐basins for forecasts with a lead time of 90 days are potential evapotranspiration with a large lag and temporal resolution, lake levels with a small lag and temporal resolution and snow storage with a small lag and large temporal resolution. The resultant correlation maps provide appropriate lags and temporal resolutions for indicators to forecast low flows in the River Rhine with different lead times. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献