鄂霍次克海南部OS03-1岩心MIS6期以来的沉积记录及其古环境意义   总被引：2，自引：1，他引：1  

司贺园  侯雪景  丁旋 《现代地质》2011,25(3):482-488

通过对取自鄂霍次克海南部的柱状岩心OS03-1的古海洋学研究,包括浮游有孔虫壳体AMS14C测年、底栖有孔虫壳体δ18O分析、蛋白石含量测定、有机碳含量测定、浮游有孔虫组合、冰筏碎屑含量变化、沉积物粒度分析等内容,建立鄂霍次克海OS03-1岩心年代地层学框架,分析该海区古表层海水温度、古生产力变化,并研究其古环境意义。结果表明,Neogloboquadrina pachyderma(sin.)百分含量变化曲线与Globigerina bulloides百分含量变化曲线呈很好的负相关性,与氧同位素曲线对比显示,两者均可作为该海区古温度替代性指标;浮游有孔虫绝对丰度、蛋白石含量、有机碳含量变化显示,研究区古生产力水平整体表现为间冰期较高、冰期较低;冰筏碎屑和沉积物粒度特征指示,鄂霍次克海南部间冰期陆源粗颗粒百分含量较冰期高。  相似文献   

毛乌素沙漠东南缘全新世剖面光释光年代及古气候意义   总被引：10，自引：6，他引：4       下载免费PDF全文

马冀  岳乐平  杨利荣  孙蕗  徐永 《第四纪研究》2011,31(1):120-129

在毛乌素沙漠东南缘锦界地区发现的具有3层深棕色至黑色古土壤的全新世剖面,记录了至少3次大型沙地固定与活化的交替演化.在锦界剖面厚约5m的全新世地层中采集了10个光释光样品,利用石英光释光测年单片再生法(SAR),建立了锦界剖面全新世(>7.5-0.2ka)年代格架.结合粒度、磁化率气候变化代用指标和光释光年龄序列,得到...  相似文献   

Reconstruction of solution chemistry evolution based on the sedimentary record of salt lakes in the Olkhon region   总被引：1，自引：0，他引：1  

O.L. Gaskova  E.P. Solotchina  O.A. Sklyarova 《Russian Geology and Geophysics》2011,52(5):548-554

  相似文献   

海温观测资料的三维时空分布和偏度特征研究     

王辉赞  张韧  安玉柱  陈奕德 《海洋通报》2011,30(2):127-134

利用包含Argo和WOD05的历史现场观测数据集,分析研究了全球历史海温观测的三维时宅分布特征,并对观测数据的偏度特征进行研究.研究结果表明:1)海温观测数据在全球许多海域(特别是南大洋和北冰洋)较为稀少,大多数观测集中在北欧沿海、北美的东西部沿海和西北太平洋区域以及其他少数区域;北半球观测数据明显多于南半球;2)海温具有明显的非对称性分布特征,其非正态分布和有偏现象是一个全球的普遍现象,且随着海区和深度而变化;非正态分布网格数量在任意给定的深度层次上占总网格数的比率超过80%:3)海温观测在各水平层次总体上具有正偏的特性,但在黑潮、湾流、南极绕极流等区域呈现出负偏的特征;具有正偏分布特征的区域网格数量占全球网格总数的比例随着深度的增加而增加,至600 m时达到75%左右.  相似文献   

中国历史地理学的回顾与展望——建所70周年历史地理学研究成果与发展前景   总被引：2，自引：1，他引：1  

王守春 《地理科学进展》2011,30(4):442-451

回顾了中国科学院地理科学与资源研究所(以下简称地理资源所)历史地理学科组成独立学科建制以来的半个多世纪中,在历史自然地理、历史人文地理、历史区域地理与历史地图编绘等方面所开展的大量工作;尤其是在历史自然地理和历史区域地理研究方面更具优势,硕果累累,在国内外有广泛影响.在对历史地理学未来研究进行展望时,特别指出由于地理资...  相似文献   

Dating of the Dome Fuji shallow ice core based on a record of volcanic eruptions from AD 1260 to AD 2001     

Makoto Igarashi  Yoichi Nakai  Yuko Motizuki  Kazuya Takahashi  Hideaki Motoyama  Kazuo Makishima 《Polar Science》2011,5(4):411-420

We measured the concentration of non-sea-salt sulfate () in the Dome Fuji shallow ice core (Antarctica) from the surface to 40 m depth with the aim of dating the core with reference to the record of volcanic eruptions. Three huge spikes related to large-scale volcanic eruptions were detected at depths of 12.5, 29.9, and 38.8 m, correlated to the eruptions of Tambora (AD 1815), Kuwae (AD 1452) and an unknown event (AD 1259), respectively. We identified another nine spikes related to accurately dated eruption events. The shallow ice core was dated from AD 1260 to AD 2001 based on these 12 eruption events and the assumption of constant annual snow accumulation in the periods between eruption events. The results yield a maximum correction of ∼20 years compared with the dating proposed in a previous study. The annual accumulation varied within ±∼15% of the average water equivalent value over the study period (25.5 mm).  相似文献   

基于MODIS数据网格化重建历史耕地空间分布的方法——以清代云南省为例   总被引：5，自引：1，他引：4  

李柯  何凡能  张学珍 《地理研究》2011,30(12):2281-2288

建立具有准确空间属性的历史时期土地覆被数据集有助于更好地模拟土地覆被变化的过程及其效应。本文基于我国过去300年耕地面积总体呈持续增加的特点,提出了历史时期耕地分布范围未超出现代耕地范围的合理假设,并以地表高程和坡度为影响土地宜垦程度的主导因子,评估了MODIS土地覆被产品中现代耕地分布区域的宜垦程度,再按宜垦程度从高...  相似文献   

Technology obscuring equity: historical responsibility in UNFCCC negotiations     

《Climate Policy》2013,13(4):339-354

According to the concept of historical responsibility, the commitments of individual countries to take action on climate change are distributed based on the relative effects of their past emissions as manifested in present climate change. Brazil presented a comprehensive version of the concept to pre-Kyoto negotiations in 1997. The ‘Brazilian proposal’ originally combined several justice principles; however, following referral to the Subsidiary Body for Scientific and Technological Advice, discussion soon became confined to technical calculations. This case illustrates how disparities in knowledge production and framing can influence the inclusiveness of negotiations. Southern participation in the policy process was restrained due to lack of scientific expertise on the part of Southern countries and due to the non-inclusive biophysical discourse traditionally preferred by Northern policy-makers. The historical responsibility issue became stranded on problems of how to correctly represent physical nature in climate models. This marginalized the original intention that equity should be the guiding principle of the North—South interaction, arguably undercutting a potential angle of approach to advance the climate change negotiations. The article concludes that in the interest of facilitating the North—South dialogue in climate change negotiations, any framing of historical responsibility that excludes equity needs to be redefined.  相似文献   

Three-Step Difference Scheme for Solving Nonlinear Time-Evolution Partial Differential Equations          下载免费PDF全文

GONG Jing  WANG Bin  JI Zhong-Zhen 《大气和海洋科学快报》2013,(6):423-427

In this paper, a special three-step difference scheme is applied to the solution of nonlinear time-evolution equations, whose coefficients are determined according to accuracy constraints, necessary conditions of square conservation, and historical observation information under the linear supposition. As in the linear case, the schemes also have obvious superiority in overall performance in the nonlinear case compared with traditional finite difference schemes, e.g., the leapfrog（LF） scheme and the complete square conservation difference（CSCD） scheme that do not use historical observations in determining their coefficients, and the retrospective time integration（RTI） scheme that does not consider compatibility and square conservation. Ideal numerical experiments using the one-dimensional nonlinear advection equation with an exact solution show that this three-step scheme minimizes its root mean square error（RMSE） during the first 2500 integration steps when no shock waves occur in the exact solution, while the RTI scheme outperforms the LF scheme and CSCD scheme only in the first 1000 steps and then becomes the worst in terms of RMSE up to the 2500th step. It is concluded that reasonable consideration of accuracy, square conservation, and historical observations is also critical for good performance of a finite difference scheme for solving nonlinear equations.  相似文献   

A 94-ka Pollen Record of Vegetation Change in Qaidam Basin,Northeastern Qinghai-Tibetan Plateau     

WEI Haicheng  FAN Qishun  ZHAO Yan  MA Haizhou  AN Fuyuan  YUAN Qin 《《地质学报》英文版》2014,88(Z1):31-33

正1 Introduction The northeastern Qinghai-Tibetan Plateau(NE QTP),located at a triple junction of influences of the Asian summer monsoon,westerly jet stream and Siberian high,is of considerable significance with regard to regional responses to global climate change.Qarhan Salt Lake is the largest playa located in the central eastern  相似文献