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Decadal prediction skill for Eurasian surface air temperature in CMIP6 models
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作者 Yanyan Huang Ni Huang Qianfei Zhao 《Atmospheric and Oceanic Science Letters》 CSCD 2024年第1期9-13,共5页
评估CMIP6年代际预测试验对季节平均SAT的预测技巧的结果表明:模式不能有效预测冬季和秋季SAT的年代际变率.IPSL-CM6A-LR和多模式集合平均对于春季SAT展现了预测技巧,其中对于变率的预测技巧好于振幅的结果.基于蒙古和我国华北地区的显... 评估CMIP6年代际预测试验对季节平均SAT的预测技巧的结果表明:模式不能有效预测冬季和秋季SAT的年代际变率.IPSL-CM6A-LR和多模式集合平均对于春季SAT展现了预测技巧,其中对于变率的预测技巧好于振幅的结果.基于蒙古和我国华北地区的显著预测技巧,模式对于夏季SAT表现出最佳的预测水平.与外部强迫相比,模式对于SAT的预测技巧可能来自初始化.模式中的一个明显系统性误差值得注意,即模式中冬季SAT的变率可以持续到其他季节,而在观测中其他季节的SAT变化与冬季SAT相对独立. 展开更多
关键词 欧亚 地表温度 年代际预测 CMIP6 DCPP
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Impact of the Shrinkage of Arctic Sea Ice on Eurasian Snow Cover Changes in 1979-2021 被引量:1
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作者 Qian YANG Shichang KANG +1 位作者 Haipeng YU Yaoxian YANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2023年第12期2183-2194,I0007,I0008,共14页
Recent research has shown that snow cover induces extreme wintertime cooling and has detrimental impacts.Although the dramatic loss of Arctic sea ice certainly has contributed to a more extreme climate,the mechanism c... Recent research has shown that snow cover induces extreme wintertime cooling and has detrimental impacts.Although the dramatic loss of Arctic sea ice certainly has contributed to a more extreme climate,the mechanism connecting sea-ice loss to extensive snow cover is still up for debate.In this study,a significant relationship between sea ice concentration(SIC)in the Barents-Kara(B-K)seas in November and snow cover extent over Eurasia in winter(November-January)has been found based in observational datasets and through numerical experiments.The reduction in B-K sea ice gives rise to a negative phase of Arctic Oscillation(AO),a deepened East Asia trough,and a shallow trough over Europe.These circulation anomalies lead to colder-than-normal Eurasian mid-latitude temperatures,providing favorable conditions for snowfall.In addition,two prominent cyclonic anomalies near Europe and Lake Baikal affect moisture transport and its divergence,which results in increased precipitation due to moisture advection and wind convergence.Furthermore,anomalous E-P flux shows that amplified upward propagating waves associated with the low SIC could contribute to the weakening of the polar vortex and southward breakouts of cold air.This work may be helpful for further understanding and predicting the snowfall conditions in the middle latitudes. 展开更多
关键词 ARCTIC Barents-Kara seas sea ice snow cover eurasia
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Hybrid Seasonal Prediction of Meridional Temperature Gradient Associated with“Warm Arctic-Cold Eurasia” 被引量:1
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作者 Tianbao XU Zhicong YIN +2 位作者 Xiaoqing MA Yanyan HUANG Huijun WANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2023年第9期1649-1661,共13页
The meridional gradient of surface air temperature associated with“Warm Arctic–Cold Eurasia”(GradTAE)is closely related to climate anomalies and weather extremes in the mid-low latitudes.However,the Climate Forecas... The meridional gradient of surface air temperature associated with“Warm Arctic–Cold Eurasia”(GradTAE)is closely related to climate anomalies and weather extremes in the mid-low latitudes.However,the Climate Forecast System Version 2(CFSv2)shows poor capability for GradTAE prediction.Based on the year-to-year increment approach,analysis using a hybrid seasonal prediction model for GradTAE in winter(HMAE)is conducted with observed September sea ice over the Barents–Kara Sea,October sea surface temperature over the North Atlantic,September soil moisture in southern North America,and CFSv2 forecasted winter sea ice over the Baffin Bay,Davis Strait,and Labrador Sea.HMAE demonstrates good capability for predicting GradTAE with a significant correlation coefficient of 0.84,and the percentage of the same sign is 88%in cross-validation during 1983−2015.HMAE also maintains high accuracy and robustness during independent predictions of 2016−20.Meanwhile,HMAE can predict the GradTAE in 2021 well as an experiment of routine operation.Moreover,well-predicted GradTAE is useful in the prediction of the large-scale pattern of“Warm Arctic–Cold Eurasia”and has potential to enhance the skill of surface air temperature occurrences in the east of China. 展开更多
关键词 warm Arctic-cold eurasia year-to-year increment climate prediction sea ice SST
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The Warm Arctic-Cold Eurasia Pattern and Its Key Region in Winter in CMIP6 Model Simulations
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作者 Liang ZHAO Yunwen LIU +6 位作者 Yihui DING Qingquan LI Wei DONG Xinyong SHEN Wei CHENG Haoxin YAO Ziniu XIAO 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2023年第12期2138-2153,I0002-I0006,共21页
An enhanced Warm Arctic-Cold Eurasia(WACE)pattern has been a notable feature in recent winters of the Northern Hemisphere.However,divergent results between model and observational studies of the WACE still remain.This... An enhanced Warm Arctic-Cold Eurasia(WACE)pattern has been a notable feature in recent winters of the Northern Hemisphere.However,divergent results between model and observational studies of the WACE still remain.This study evaluates the performance of 39 climate models participating in the Coupled Model Intercomparison Project Phase 6(CMIP6)in simulating the WACE pattern in winter of 1980-2014 and explores the key factors causing the differences in the simulation capability among the models.The results show that the multimodel ensemble(MME)can better simulate the spatial distribution of the WACE pattern than most single models.Models that can/cannot simulate both the climatology and the standard deviation of the Eurasian winter surface air temperature well,especially the latter,usually can/cannot simulate the WACE pattern well.This mainly results from the different abilities of the models to simulate the range and intensity of the warm anomaly in the Barents Sea-Kara seas(BKS)region.Further analysis shows that a good performance of the models in the BKS area is usually related to their ability to simulate location and persistence of Ural blocking(UB),which can transport heat to the BKS region,causing the warm Arctic,and strengthen the westerly trough downstream,cooling central Eurasia.Therefore,simulation of UB is key and significantly affects the model’s performance in simulating the WACE. 展开更多
关键词 warm Arctic-cold eurasia pattern Arctic amplification CMIP6 simulation evaluation extreme climate blocking highs
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Subseasonal transition of Barents-Kara sea-ice anomalies in winter related to the reversed warm Arctic-cold Eurasia pattern 被引量:1
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作者 Yijia Zhang Zhicong Yin Huijun Wang 《Atmospheric and Oceanic Science Letters》 CSCD 2023年第5期49-54,共6页
“暖北极-冷欧亚”模态(WACE)的次季节反转会触发中国东部冬季的极端冷/暖转换以及春季沙尘暴.在这一显著的高纬度大气模态反转的驱动下,巴伦支海-喀拉海(BKS)的海冰异常也表现出次季节转换.当北极变暖以及乌拉尔山高压增强时,BKS异常... “暖北极-冷欧亚”模态(WACE)的次季节反转会触发中国东部冬季的极端冷/暖转换以及春季沙尘暴.在这一显著的高纬度大气模态反转的驱动下,巴伦支海-喀拉海(BKS)的海冰异常也表现出次季节转换.当北极变暖以及乌拉尔山高压增强时,BKS异常向下的湍流热通量和增强的向下红外辐射有利于海冰融化;近地面的异常偏南风使海冰从薄冰区向多年冰区漂移,进一步扩大了开阔洋面.相反的机制出现在WACE反位相,导致BKS海冰异常偏多.当WACE次季节反转时,上述机制分别发生在前冬和后冬,使得BKS海冰异常出现显著的次季节转换.近10年随着WACE反转频率增多,BKS海冰前后冬的次季节变化增强.本文构建了WACE次季节反转的综合示意图,有助于更好地理解和预测中国东部极端气候. 展开更多
关键词 暖北极-冷欧亚 巴伦支海-喀拉海海冰 次季节变化 湍流热通量 海冰漂移
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Eurasian Economic Union's Effect on Global Politics and the World Economic System
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作者 Askm inci Sokmen 《International Relations and Diplomacy》 2015年第10期699-714,共16页
The new Eurasian Economic Union (EEU) has now become a reality coming into effect today allowing free movement of trade, services and capital. Its treaty was signed on 29 May 2014 by the leaders of Belarus, Kazakhst... The new Eurasian Economic Union (EEU) has now become a reality coming into effect today allowing free movement of trade, services and capital. Its treaty was signed on 29 May 2014 by the leaders of Belarus, Kazakhstan and Russia. EEU has an integrated single market of 176 million people and a gross domestic product (GDP) of over four trillion US Dollars. From the point view of Nye and Keohane's interdepence theory, this trade block formed under Moscow's leadership also begs the question, if the Soviet Union will also reunite and be re-established. Russia seems to look at it not just in economic terms, but as a way to expand Russian influence in the region. The biggest criticism of the union seems to be re-establishment of the crumbled Soviet Union. On the other hand Russia has wanted to launch talks with the newly born EEU despite the Ukraine Crisis. German Chancellor Angele Merkel has supported to establish a common economic space in the Eurasian Region including the focus countries of Eastern Partnership (an EU policy on closer ties with Armenia, Azerbaijan, Belarus, Georgia, Moldova and Ukraine). A new Russia-led blocs as a better partner for the EU than the US could cause to deemphasize new Trans-Atlantic Treaty. Another point, the union is actively seeking to increase trade with East Asia. It commenced talks for official trade cooperation with Association of Southeast Asian Nations (ASEAN). Therefore we can say that EEU includes strategic interests as well as economic interests for its members, especially for Russia. In order to link both Europe and East Asia, Russia seeks to develop its eastern regions to increase its access to Asian markets. Far East markets have become so important for Russia since the European Union and the United States imposed sanctions on Russia following crisis in Ukraine. In this article my aim is to analyze EEU effects on global politics and the World Economic System. 展开更多
关键词 RUSSIA eurasian Economic Union geopolitics and geo-economy of eurasia new power economicalbalance in global competition
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Structural and Chronological Evidence for the India-Eurasia Collision of the Early Paleocene in the Eastern Himalayan Syntaxis, Namjagbarwa 被引量:10
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作者 张进江 季建清 +2 位作者 钟大赉 桑海清 何顺东 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2002年第4期446-454,共9页
The eastern Himalayan syntaxis in Namjagbarwa is a high-grade metamorphicterrain formed by the India-Eurasia collision and northward indentation of the Indian continent intoAsia. Right- and left-lateral slip zones wer... The eastern Himalayan syntaxis in Namjagbarwa is a high-grade metamorphicterrain formed by the India-Eurasia collision and northward indentation of the Indian continent intoAsia. Right- and left-lateral slip zones were formed by the indentation on the eastern and westernboundaries of the syntaxis respectively. The Dongjug-Mainling fault zone is the main shear zone onthe western boundary. This fault zone is a left-lateral slip belt with a large component ofthrusting. The kinematics of the fault is consistent with the shortening within the syntaxis, andthe slipping history along it represents the indenting process of the syntaxis. The Ar-Archronological study shows that the age of the early deformation in the Dongjug-Mainling fault zoneranges from 62 to 59 Ma. This evidences that the India-Eurasia collision occurred in the earlyPaleocene in the eastern Himalayan syntaxis. 展开更多
关键词 India-eurasia collision eastern Himalayan syntaxis Namjagbarwa structuralchronology Paleocene
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Improvement of Soil Moisture Simulation in Eurasia by the Beijing Climate Center Climate System Model from CMIP5 to CMIP6 被引量:5
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作者 Yinghan SANG Hong-Li REN +2 位作者 Xueli SHI Xiaofeng XU Haishan CHEN 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2021年第2期237-252,共16页
This study provides a comprehensive evaluation of historical surface soil moisture simulation(1979-2012)over Eurasia at annual and seasonal time scales between two medium-resolution versions of the Beijing Climate Cen... This study provides a comprehensive evaluation of historical surface soil moisture simulation(1979-2012)over Eurasia at annual and seasonal time scales between two medium-resolution versions of the Beijing Climate Center Climate System Model(BCC-CSM)—one that is currently participating in phase 6 of the Coupled Model Intercomparison Project(CMIP6),i.e.,BCC-CSM2-MR,and the other,BCC-CSM1.1m,which participated in CMIP5.We show that BCC-CSM2-MR is more skillful in reproducing the climate mean states and standard deviations of soil moisture,with pattern correlations increased and biases reduced significantly.BCC-CSM2-MR performs better in capturing the first two primary patterns of soil moisture anomalies,where the period of the corresponding time series is closer to that of reference data.Comparisons show that BCC-CSM2-MR performs at a high level among multiple models of CMIP6 in terms of centered pattern correlation and“amplitude of variation”(relative standard deviation).In general,the centered pattern correlation of BCC-CSM2-MR,ranging from 0.61 to 0.87,is higher than the multi-model mean of CMIP6,and the relative standard deviation is 0.75,which surmounts the overestimations in most of the CMIP6 models.Due to the vital role played by precipitation in land-atmosphere interaction,possible causes of the improvement of soil moisture simulation are further related to precipitation in BCC-CSM2-MR.The results indicate that a better description of the relationship between soil moisture and precipitation and a better reproduction of the climate mean precipitation by the model may result in the improved performance of soil moisture simulation. 展开更多
关键词 BCC-CSM soil moisture CMIP6 historical simulation eurasia
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Seasonal evolution of the dominant modes of the Eurasian snowpack and atmospheric circulation from autumn to the subsequent spring and the associated surface heat budget 被引量:5
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作者 SUN Bo 《Atmospheric and Oceanic Science Letters》 CSCD 2017年第3期191-197,共7页
This study investigates the seasonal evolution of the dominant modes of the Eurasian snowpack and atmospheric circulation from autumn to the subsequent spring using snow water equivalent (SWE), snow cover frequency ... This study investigates the seasonal evolution of the dominant modes of the Eurasian snowpack and atmospheric circulation from autumn to the subsequent spring using snow water equivalent (SWE), snow cover frequency (SCF), and 500 hPa geopotential height data. It is found that the Eurasian SWE/SCF and circulation dominant modes are stably coupled from autumn to the subsequent spring.The temporal coherence of the seasonal evolution of the dominant modes is examined.The seasonal evolution of the Eurasian circulation and SWE dominant modes exhibit good coherence, whereas the evolution of the Eurasian SCF dominant mode is incoherent during the autumn-winter transition season. This incoherence is associated with a sign-change in the SCF anomalies in Europe during the autumn-winter transition season, which is related to the wind anomalies over Europe. In addition, the surface heat budget associated with the Eurasian SWE/SCF and circulation dominant modes is analyzed. The sensible heat flux (SHF) related to the wind-induced thermal advection dominates the surface heat budget from autumn to the subsequent spring, with the largest effect during winter. The surface net shortwave radiation is mainly modulated by snow cover rather than cloud cover, which is estimated to be as important as, or likely superior to, the SHF for the surface heat budget during spring.The NCEP-NCAR surface heat flux reanalysis data demonstrate a consistency with the SWE/SCF and air temperature observational data, indicating a good capability for snow-atmosphere interaction analysis. 展开更多
关键词 eurasia dominant mode SNOW atmospheric circulation surface heat budget
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An Objective Identification Method for Wintertime Cold Fronts in Eurasia 被引量:1
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作者 Mengru FENG Yujing QIN Chuhan LU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2021年第10期1695-1705,共11页
The present study identifies wintertime cold fronts in Eurasia from gridded datasets using a new objective two-step identification scheme.The simple and classic conception of a front is adopted,where a cold front is i... The present study identifies wintertime cold fronts in Eurasia from gridded datasets using a new objective two-step identification scheme.The simple and classic conception of a front is adopted,where a cold front is identified as the warm boundary of the frontal zone with a suitable horizontal temperature gradient and cold advection.We combine the traditional thermal front parameter with temperature advection to first identify the cold frontal zone,and then its eastern and southern boundaries are objectively plotted as a cold front in Eurasia.By comparing different cold front identification methods,the results from this two-step cold front identification method and subjective analysis are more consistent,and the positions of the cold front identified with our method are more reasonable.This objective technique is also applied to a nationwide cold wave event over China.Results show that the horizontal extent and movement of the cold front are in good agreement with the related circulation and the associated cold weather.The proposed method and results in this study may shed light on the rapid identification of cold fronts in operational weather analysis and facilitate further research on the long-term activity characteristics of continental cold fronts. 展开更多
关键词 cold front thermal front parameter objective identification eurasia WINTER
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Opposing Trends of Winter Cold Extremes over Eastern Eurasia and North America under Recent Arctic Warming 被引量:1
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作者 Shuangmei MA Congwen ZHU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2020年第12期1417-1434,共18页
Under recent Arctic warming,boreal winters have witnessed severe cold surges over both Eurasia and North America,bringing about serious social and economic impacts.Here,we investigated the changes in daily surface air... Under recent Arctic warming,boreal winters have witnessed severe cold surges over both Eurasia and North America,bringing about serious social and economic impacts.Here,we investigated the changes in daily surface air temperature(SAT)variability during the rapid Arctic warming period of 1988/89–2015/16,and found the daily SAT variance,mainly contributed by the sub-seasonal component,shows an increasing and decreasing trend over eastern Eurasia and North America,respectively.Increasing cold extremes(defined as days with daily SAT anomalies below 1.5 standard deviations)dominated the increase of the daily SAT variability over eastern Eurasia,while decreasing cold extremes dominated the decrease of the daily SAT variability over North America.The circulation regime of cold extremes over eastern Eurasia(North America)is characterized by an enhanced high-pressure ridge over the Urals(Alaska)and surface Siberian(Canadian)high.The data analyses and model simulations show the recent strengthening of the high-pressure ridge over the Urals was associated with warming of the Barents–Kara seas in the Arctic region,while the high-pressure ridge over Alaska was influenced by the offset effect of Arctic warming over the East Siberian–Chukchi seas and the Pacific decadal oscillation(PDO)–like sea surface temperature(SST)anomalies over the North Pacific.The transition of the PDO-like SST anomalies from a positive to negative phase cancelled the impact of Arctic warming,reduced the occurrence of extreme cold days,and possibly resulted in the decreasing trend of daily SAT variability in North America.The multi-ensemble simulations of climate models confirmed the regional Arctic warming as the driver of the increasing SAT variance over eastern Eurasia and North America and the overwhelming effect of SST forcing on the decreasing SAT variance over North America.Therefore,the regional response of winter cold extremes at midlatitudes to the Arctic warming could be different due to the distinct impact of decadal SST anomalies. 展开更多
关键词 daily surface air temperature variability extreme cold days Arctic warming eastern eurasia North America
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Combined impact of the Pacific–Japan pattern and Mediterranean–northern Eurasia pattern on East Asian summer temperatures 被引量:1
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作者 MING Jing SUN Jianqi YU Shui 《Atmospheric and Oceanic Science Letters》 CSCD 2019年第3期208-217,共10页
The combined effect of the Pacific–Japan (PJ) pattern and Mediterranean–northern Eurasia (MnE) pattern on East Asian surface air temperature (SAT) during summer is investigated using the Japanese 55-year reanalysis ... The combined effect of the Pacific–Japan (PJ) pattern and Mediterranean–northern Eurasia (MnE) pattern on East Asian surface air temperature (SAT) during summer is investigated using the Japanese 55-year reanalysis and Climatic Research Unit SAT data over the period of 1958–2016. The results show that the combination of the two patterns in different phases can result in different SAT anomalies. During the in-phase PJ-MnE years, the overlapping of opposite signs of the atmospheric circulations associated with the PJ and MnE patterns results in weak atmospheric circulation and SAT anomalies in central East Asia;during these years, the significant SAT anomalies are over northern East Asia. In contrast, during the out-of-phase PJ-MnE years, the overlapping of the same signs of the atmospheric circulations associated with the PJ and MnE patterns leads to significant atmospheric circulation and SAT anomalies in central East Asia and northern Asia. The analysis in this study indicates that to better understand and predict the variability of East Asian summer SATs, the combined effect of the PJ and MnE patterns should be taken into account. 展开更多
关键词 East Asia surface air temperature Pacific–Japan pattern Mediterranean– northern eurasia pattern
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Intercontinental response to variations in the Arabia-Eurasia Plate convergence,calcite e-twin evidence of the Kuhbanan Fault system,Central Iran
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作者 Sara ESMAEILIAN Saeed MADANIPOUR +1 位作者 Shahram SHAAFIEIBAFTI Yasamin EBRAHIMI 《Journal of Mountain Science》 SCIE CSCD 2021年第5期1321-1339,共19页
Variations in the plate convergence direction have generally reflected on the kinematics of the major fault zones developed in the intercontinental parts of the collision zones.The Kuhbanan Fault system is one of the ... Variations in the plate convergence direction have generally reflected on the kinematics of the major fault zones developed in the intercontinental parts of the collision zones.The Kuhbanan Fault system is one of the most important intercontinental faults in the Arabia-Eurasia collision zone with a dextral strike slip mechanism.This fault system is composed of three fault strands including Kuhbanan,Bazargan,and Kerman Faults.Here we used calcite e-twin analysis of the vein samples developed in these fault zones to reconstruct deformation condition and the paleodifferential stress direction and magnitude at the Kuhbanan Fault system.Our results represent 190°C-200°C of the deformation temperature and related 5–6±1 km of deformation depth at the Kuhbanan Fault system.Calculated paleodifferential stress magnitude in the Kuhbanan Fault system using e-twin parameters ranges from 169-196 MPa similar to the inner parts of the orogenic systems.Comparing the data set of the Kuhbanan Fault system with previous studies at the Zagros orogen represents an increase of deformation depth and paleodifferential stress magnitudes from the foreland of the Zagros orogen to its hinterland and finally northward around the Kuhbanan Fault system in the central Iranian blocks.We have also proposed a shift of the stress direction from paleo NE to recent N directed by comparing paleostress direction deduced from the calcite e-twin and recent stress direction calculated from GPS and earthquake data analysis around the Kuhbanan Fault system.This kinematics change due to plate reorganization is in agreement with the observed regional variation in convergence direction all in the Arabia-Eurasia collision zone. 展开更多
关键词 Kuhbanan Fault system Calcite e-twin analysis Paleodifferential stress Arabia eurasia collision Central Iranian blocks Paleostress analysis
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Stress Transfer and the Impact of the India-Eurasia Collision and the Western Pacific Subduction on the Geodynamics of the Asian Continent 被引量:1
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作者 Victor. G. Bykov Tatyana V. Merkulova 《Open Journal of Earthquake Research》 2022年第4期73-88,共16页
The interaction between the India-Eurasia collision and the Western Pacific subduction and their contribution to recent geodynamics of the Asian continent are discussed. We perform a comparative analysis of the data a... The interaction between the India-Eurasia collision and the Western Pacific subduction and their contribution to recent geodynamics of the Asian continent are discussed. We perform a comparative analysis of the data available from world literature and new data on the slow strain and earthquake migration from the India-Eurasia collision and the Western Pacific subduction zones. Based on the concepts of wave dynamics of the deformation processes, a localization scheme is constructed illustrating the migration of slow strain fronts in central and eastern Asia, and the wave geodynamic impact of collision and subduction on the Asian continent is shown. 展开更多
关键词 Stress Transfer Earthquake Migration Slow Strain Fronts GEODYNAMICS India-eurasia Collision Western Pacific Subduction
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Permo–Triassic and Liassic Tethyan Oceanic Tracts within the Pontide Belt Along the Southern Margin of Eurasia, Northern Anatolia
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作者 E.SARIFAKIOGLU Y.DILEK +7 位作者 M.SEVIN S.PEHLIVAN O.K EMIR A.MOLLER T.BAYANOVA I.UYSAL M.KELES 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2017年第S1期33-34,共2页
The Pontide belt in northern Turkey includes three major tectonic terranes,the Strandja Massif(Sj M),and the Istanbul(ISZ)and Sakarya Zones(SZ)(Fig.1).We present new age and geochemical data from ophiolites and ... The Pontide belt in northern Turkey includes three major tectonic terranes,the Strandja Massif(Sj M),and the Istanbul(ISZ)and Sakarya Zones(SZ)(Fig.1).We present new age and geochemical data from ophiolites and ophiolitic mélanges within the Sakarya Zone and show that these mafic–ultramafic rocks are the remnants of Tethyan oceanic lithosphere formed in different tectonic settings.The main ophiolite occurrences investigated in this study along the Karakaya Suture(KS)are associated with the latest Triassic Cimmeride orogeny,and in the Küre–Yusufeli ophiolite belt are part of the Alpide orogeny.The Karakaya Suture Zone ophiolites in northern west Turkey are comprised mainly of the Denizgoren(?anakkale)ophiolite,Bo?azk?y(Bursa),Geyve(Sakarya),Almac?k(Düzce)and?ele(Bolu)metaophiolites.The Denizg?ren ophiolite largely contains upper mantle peridotites,which are equivalents of the Permo–Triassic Lesvos peridotites and mélange units farther SW in the northern Aegean Sea.The Bo?azk?y ophiolite includes serpentinite and metagabbro,and the Almac?k and Geyve ophiolites display an almost complete Penrose–type sequence consisting of serpentinizeduppermantleperidotites,cumulate ultramafic–mafic rocks,isotropic gabbros,dolerite and plagiogranite dikes,and extrusive rocks.U–Pb zircon dating of plagiogranite dikes from?ele has revealed an igneous age of 260 Ma,and 255,235,227 Ma from Almac?k(Bozkurt et al.,2012a,b).Consistent with the previouslypublished Permo–Triassic age,we obtained a 268.4±6.3 Ma U–Pb zircon age from a plagiogranite dike within the Almacik ophiolite to the west.This KS ophiolite belt containing the?ele,Almac?k,Geyve ophiolites within the SZ extends westward into the Armutlu Peninsula and then into the Biga Peninsula(i.e.Denizg?ren ophiolite)and most likely connects with the remnants of the Triassic Meliata–Meliac ocean basin(Stampfli and Borel,2002)in the Balkan Peninsula.The KS ophiolites also continue eastward within the Pontide Belt into the Elekda?ophiolite(eastern Kastamonu)and then to the Refahiye ophiolite in NE Anatolia.Triassic granites in the SZ represent a magmatic arc that formed as a result of the northward subduction of the Izmir–Ankara–Erzincan oceanic lithosphere existing during the late Paleozoic through Cretaceous(Sarifakioglu et al.,2014)beneath the Pontides.We obtained a U–Pb zircon age of 231±2 Ma from a metagranitic intrusion into the Variscan basement of the SZ in the Kastamonu region of the central Pontides.This metagranite is enriched in LILE(Rb:63 ppm;Ba:65 ppm;Sr:200 ppm)and depleted in HFSE(Y:12.58 ppm;Yb:1.26 ppm;Ti O2:0.2 wt.%;Nb:7.6 ppm;Hf:3.9 ppm),characterizing it as subduction–related calc-alkaline pluton.Lead(3.9 ppm),U(1.6 ppm)and Ce(59 ppm)contents are interpreted as evidence for contamination by continental crust.The Küre basin to the north opened during the late Triassic to Liassic,following a backarc rifting episode in the central Pontides.Metabasic dike intrusions in the Devrekani metamorphic massif represent the first magmatic stage of this backarc rifting event.Whole-rock 40Ar-39Ar dating ofthe metabasic dikes has yielded cooling ages of 160.5±1.2 Ma. We infer that this age was reset due to thermal heating during the emplacement of the Middle Jurassic granitoids as the Küre oceanic basin was closing. The Küre ophiolite contains upper mantle peridotites and oceanic crustal rocks composed mainly of pillow–massive–breccia basalts, dacitic and rhyolitic lavas–tuffs, diabase dyke swarms, massive gabbros and a limited extent mafic cumulates. We obtained 182.6±1.9 Ma as a whole-rock 40Ar-39 Ar age from a pillow basalt and a U–Pb zircon age of 171±1 Ma from the granitic intrusion cross-cutting the peridotites. The easternmost representatives of the Küre ophiolite occur in the Yusufeli(Artvin) area in the eastern part of the Pontide belt. Here, oceanic crustal rocks are tectonically related to metamorphic rocks of the Variscan basement of the SZ. The ophiolitic crustal rocks contain isotropic gabbro and mafic and felsic dikes. Serpentinized upper mantle peridotites are scarce. Pillow lava basalts are overlain by a thick metasandstone–metashale association with locally foliated meta–lava and some manganiferous chert and mudstone interlayers. We obtained a U–Pb zircon age of 172.5±1.4 Ma from the granitic intrusion cross-cutting the Yusufeli ophiolite and of 181.9±0.9 Ma from a felsic dike(plagiogranite) in the Yusufeli ophiolite. The Middle Jurassic granites are related to the closure of the Küre-Yusufeli marginal ocean basin. The Küre and Yusufeli ophiolites have been previously interpreted as the remnants of the Paleotethys or the Intra-Pontide Ocean. However, we posit that these ophiolites represent amarginal, short-lived(;0 Ma) ocean basin, which opened during the late Triassic through Liassic, and then closed in Dogger. This oceanic lithosphere is similar to the Evros ophiolite in the northeastern Greece in terms of its ages and geochemical characteristics. 展开更多
关键词 Triassic and Liassic Tethyan Oceanic Tracts within the Pontide Belt Along the Southern Margin of eurasia rock KS Pb Permo Northern Anatolia
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Kimmeridgian Foraminiferal Faunas of Northern Eurasia: Significance for Interregional Correlations and Palaeobiogeography
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作者 Clémentine Peggy Anne-Marie Colpaert Boris Leonidovich Nikitenko 《Open Journal of Geology》 2019年第10期573-576,共4页
Foraminifer is a very useful microorganism to perform biostratigraphical zonation of the Upper Jurassic. Foraminiferal biozones are calibrated by the ammonite standard zones and can be used for intra- and interregiona... Foraminifer is a very useful microorganism to perform biostratigraphical zonation of the Upper Jurassic. Foraminiferal biozones are calibrated by the ammonite standard zones and can be used for intra- and interregional correlations. Furthermore, the fossil record of foraminiferal faunas is well known among basins of the Northern Eurasia and is also used for accurate palaeoenvironmental, palaeobiogeographical, or biofacial reconstructions. It allows identifying a complex set of biotic and abiotic events which may be used to propose a more general palaeoecoloecological and palaeoceanographical reconstruction of the Subboreal, Boreal, and Arctic seas. Then, the late Kimmeridgian Northern Eurasian seas formed a network of well-connected palaeobasins during the sea-level rise and resulted in rather similar palaeoenvironmental conditions. 展开更多
关键词 Late Jurassic FORAMINIFERS PALAEOCEANOGRAPHY Northern eurasia
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The Impact of the Emergence of Eurasian Art Communities in the Globalizing World
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作者 Munira Shahidi 《International Relations and Diplomacy》 2016年第3期209-218,共10页
Eurasian art study is an interdisciplinary approach to the solution of the problems of ethno-national rivalry and contradictions, dominating in the world. Although the roots of Eurasian arts goes back to Aristotelian-... Eurasian art study is an interdisciplinary approach to the solution of the problems of ethno-national rivalry and contradictions, dominating in the world. Although the roots of Eurasian arts goes back to Aristotelian-Avicennian tradition, created in Central Asia (CA) of the eve of the last millennium, the evidence of that common tradition: archaeological, philological, philosophical, linguistic, etc., interconnected with each other and recognized by the diversity of the academic schools of the last century, are not included into educational programs of the universities of the modem times. That miss, creating a gap in the world system of knowledge, restricts development of international affairs and diplomacy in its global significance. To bridge that gap, observing and analysing what was missed in the system of knowledge and how Eurasian arts communities are organizing themselves in CA of pre-soviet times, how they managed to develop through the last century and what is their perspectives now, in globalizing world, is the aim of this paper. 展开更多
关键词 eurasia Central Asia Ibn Sina jadidism communities music literature ARTS TAJIKISTAN
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Structural Evolution of the Eastern Margin of Eurasia in Late Mesozoic and Cenozoic
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作者 A.P.Sorokin T.V.Artyomenko 《Global Geology》 2003年第2期149-159,共8页
This paper features the structural evolution of the eastern margin of Eurasia in Late Mesozoic and Cenozoic. It is characterized by three stages of development: the riftogenic stage (Jurassic-Early Cretaceous), the pl... This paper features the structural evolution of the eastern margin of Eurasia in Late Mesozoic and Cenozoic. It is characterized by three stages of development: the riftogenic stage (Jurassic-Early Cretaceous), the platform stage (Late Cretaceous) and the neotectonic one (Paleogene-Quarternary). The boundaries between these stages are distinctly fixed by the geological time limits of planetary range. It is demonstrated that the riftogenic and neotectonic stages were characterized by a high degree of geodynamic activity, and the platform one by a decrease in contrast of tectonic movements. The main river net was formed in the Early Cretaceous and in the Neogene. It experienced a serious reconstruction accompanied by the formation of the Amur River valley being similar to the modern one. 展开更多
关键词 structunal evolution EASTERN MARGIN of eurasia LATE MESOZOIC and CENOZOIC
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Snow water equivalent over Eurasia in the next 50 years projected by aggregated CMIP3 models
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作者 LiJuan Ma Yong Luo DaHe Qin 《Research in Cold and Arid Regions》 2012年第2期93-106,共14页
Based on remote sensing snow water equivalent (SWE) data, the simulated SWE in 20C3M experiments from 14 models attend- hag the third phase of the Coupled Models for Inter-comparison Project (CMIP3) was first eval... Based on remote sensing snow water equivalent (SWE) data, the simulated SWE in 20C3M experiments from 14 models attend- hag the third phase of the Coupled Models for Inter-comparison Project (CMIP3) was first evaluated by computing the different percentage, spatial correlation coefficient, and standard deviation of biases during 1979-2000. Then, the diagnosed ten models that performed better simulation in Eurasian SWE were aggregated by arithmetic mean to project the changes of Eurasian SWE in 2002-2060. Results show that SWE will decrease significantly for Eurasia as a whole in the next 50 years. Spatially, significant decreasing trends dominate Eurasia except for significant increase in the northeastern part. Seasonally, decreasing proportion will be greatest in summer indicating that snow cover in wanner seasons is more sensitive to climate warming. However, absolute decreasing trends are not the greatest in winter, but in spring. This is caused by the greater magnitude of negative trends, but smaller positive trends in spring than in winter. The changing characteristics of increasing in eastern Eurasia and decreasing in western Eurasia and over the Qinghai-Tibetan Plateau favor the viewpoint that there will be more rainfall in North China and less in the middle and lower reaches of the Yangtze River in summer. Additionally, the decreasing rate and extent with significant decreasing trends under SRES A2 are greater than those under SRES B1, indicating that the emission of greenhouse gases (GHG) will speed up the decreasing rate of snow cover both temporally and spatially. It is crucial to control the discharge of GHG emissions for mitigating the disappearance of snow cover over Eurasia. 展开更多
关键词 snow water equivalent PROJECTION CMIP3 eurasia climate change simulation
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Lianyungang——Head on the New Eurasia Continental Bridge
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作者 Zhao Ming Li Zukun 《China's Foreign Trade》 1996年第10期43-43,共1页
Since the new Eurasia ContinentalBridge was formally opened in 1992,the East Bridge Tower-- Lianyungang-- has been attracting more and more attentionin the circles of transport and trade worldwide.In 1995, Lianyungang... Since the new Eurasia ContinentalBridge was formally opened in 1992,the East Bridge Tower-- Lianyungang-- has been attracting more and more attentionin the circles of transport and trade worldwide.In 1995, Lianyungang successfully organizedwhole line transport by rail for internationaltransit containers, and freight volume on theContinental Bridge is growing at an acceleratedspeed. At present, Lianyungang hasundertaken the task of transport for the totaltransit containers along the new EurasiaContinental Bridge. The countries and regionsthat make use of the Continental Bridge toconduct transport include the USA, SouthKorea, Japan, Kazakhstan and Hongkong.Between 1992 and 1995, a total of 8。 展开更多
关键词 area Lianyungang Head on the New eurasia Continental Bridge LINE
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