The temporal and spatial variability of the Yellow Sea Cold Water Mass in the southeastern Yellow Sea, 2009-2011

The Yellow Sea Cold Water Mass(YSCWM) is one of the important water mass in the Yellow Sea(YS).It is distributed in the lower layer in the Yellow Sea central trough with the temperature less than 10 C and the salinity lower than 33.0.To understand the variability of the YSCWM,the hydrographic data obtained in April and August during 2009–2011 are analyzed in the southeastern Yellow Sea.In August 2011,relatively warm and saline water compared with that in 2009 and 2010 was detected in the lower layer in the Yellow Sea central area.Although the typhoon passed before the cruise,the salinity in the Yellow Sea central trough is much higher than the previous season.It means that the saline event cannot be explained by the typhoon but only by the intrusion of saline water during the previous winter.In April 2011,actually,warm and saline water(T >10 C,S >34) was observed in the deepest water depth of the southeastern area of the Yellow Sea.The wind data show that the northerly wind in 2011 winter is stronger than in 2009 and 2010 winter season.The strong northerly wind can trigger the intrusion of warm and saline Yellow Sea Warm Current.Therefore,it is proposed that the strong northerly wind in winter season leads to the intrusion of the Yellow Sea Warm Current into the Yellow Sea central trough and influenced a variability of the YSCWM in summer.     

Discrimination between coastal subenvironments using textural characteristics

The objective of this study was to discriminate between modern beach subenvironments based on textural characteristics obtained using the graphical (percentile) method, the moment method, and the log-hyperbolic distribution (LHD). A total of 126 surface sedimentation units were sampled at the nodes of a 21 x 6 rectangular grid (1000 m²) on a carbonate sand beach, Oahu, Hawaii. Sampling was conducted at low energy conditions from the lower foreshore to the backshore. Non-parametric discriminant analysis was used as an objective tool in defining distinct subenvironments. Confidence bands around the canonical variates derived from the graphic mean, sorting, skewness and kurtosis indicated four separate subenvironments (lower foreshore, mid-foreshore, upper foreshore and backshore). Three distinct subenvironments were identified using the mean, sorting (standard deviation) and skewness measures derived by the method of moments. A similar subenvironment distinction was obtained using five statistics of the LHD (gamma, γ; nu ν; delta, δ; tau, τ; and xi, ξ). No significant difference was noted in textural characteristics between the upper foreshore and backshore zones, and these zones were grouped into one subenvironment. These results indicate that different process scenarios would be needed to explain different subenvironment partitioning based simply on the approach adopted. Discriminant analysis indicated that fewer subenvironment samples were misclassified and separation distances between subenvironments in bivariate canonical plots were greater for the standard moment measures compared with the statistics derived from fitting the computationally intensive LHD model. Examination of the mass frequency grain size distributions indicated that the LHD was generally the most appropriate model. These observations were confirmed by the hyperbolic shape triangle which indicated that the LHD rather than the more commonly used log-normal distribution was generally optimal in describing sediments. These results support the use of the LHD statistical measures in subenvironment discrimination over the graphic-inclusive measures.     

Provenance of Cored Sediments from Active Margin off Southwestern Taiwan Deduced from Geochemical Constraints

The cored sediments sampled by R/V Marion Dufrense in the active margin off southwestern Taiwan on the east side of the Manila Trench are mostly muds consisting mainly of quartz, feldspar, illite, chlorite ＋ kaolinite with a trace amount of montmorillonite. The cored sediments have higher Fe, Ti, Cr, Cs, Li, Ni, and V but lower Ca, Na, Mn, Hf, Nb, Sr, Ta, U and Zr contents when compared with the upper continental crust（UCC, Taylor and McLennan, 1985）. The Eu/Eu＊ ratios of the sediments averaging 0.69 indicate that the recycling effect on the Eu anomaly may be minor and the contribution of mafic source rock was unimportant, which can also be depicted in the La-Th-Sc plot（Cullers, 1994） showing a ＂mixed origin＂ close to the felsic end member. The chemistry of the cored sediment can be explained by a mixing model designed by Ho and Chen（1996） with four end members i.e., greywacke, shale, quartzite and limestone, which are widely distributed in the Cenozoic formations of southern Taiwan with greywacke as the dominant contributor followed by shale.     

西南喀斯特地区几种主要土地覆被下土壤CO2-C通量研究

中国西南喀斯特地区土壤营养元素流失形势严峻,揭示不同土地覆被下土壤CO2-C的释放规律,是认识喀斯特这一特殊环境诸多营养元素循环问题的一个重要途径。采用静态箱-气相色谱法对贵州喀斯特地区4种不同土地覆被下的土壤CO2-C释放通量进行观测研究。结果表明,（1）不同的土地覆被下土壤CO2-C释放通量有显著的差别,其释放顺序为：森林（（134．1±78．8）mg／（m^2·h））〉次生林（（70．8±122．3）mg／（m^2·h））〉玉米地（（55．5±78．0）mg／（m^2·h）1〉烧荒地（（35．5±91．4）mg／（m^2·h））。各样点季节变化都比较明显,夏季平均排放量最高,冬季最低。（2）凋落物对森林土壤CO2-C释放的影响较大,有凋落物覆盖的土壤CO2-C释放量（（134．1±78．8）mg／（m^2·h））高于无凋落物覆盖的林地土壤（（111．2±80．3）mg／（m^2·h））,凋落物分解对森林土壤CO2-C释放总量的贡献约占17％。基于地面气温,计算得出森林和森林（无凋落物）的研。分别为1．92、2．10。（3）除次生林和烧荒地外,其余各样地CO2-C释放通量均与土壤各层温度呈显著正相关关系,但绝大多数样地与土壤湿度（WFPS）之间相关性不显著。     

Reservoir attenuation of floods from ungauged basins

Abstract

In a typical reservoir routing problem, the givens are the inflow hydrograph and reservoir characteristic functions. Flood attenuation investigations can be easily accomplished using a hydrological or hydraulic routing of the inflow hydrograph to obtain the reservoir outflow hydrograph, unless the inflow hydrograph is unavailable. Although attempts for runoff simulation have been made in ungauged basins, there is only a limited degree of success in special cases. Those approaches are, in general, not suitable for basins with a reservoir. The objective of this study is to propose a procedure for flood attenuation estimation in ungauged reservoir basins. In this study, a kinematic-wave based geomorphic IUH model was adopted. The reservoir inflow hydrograph was generated through convolution integration using the rainfall excess and basin geomorphic information. Consequently, a fourth-order Runge-Kutta method was used to route the inflow hydrograph to obtain the reservoir outflow hydrograph without the aid of recorded flow data. Flood attenuation was estimated through the analysis of the inflow and outflow hydrographs of the reservoir. An ungauged reservoir basin in southern Taiwan is presented as an example to show the applicability of the proposed analytical procedure. The analytical results provide valuable information for downstream flood control work for different return periods.     

谁先发现美洲新大陆——中国地理学西传考证

1593年刻印的《乾坤万国全图天下人物事迹》地图载有亚伯尔耕、加拿大的名字,没有亚墨利加,显示明代知道新大陆的地名比利玛窦制作的《坤舆万国全图》早9年。1570年的奥特里斯的世界地图说明欧洲还没有到过美洲西部。普兰修斯1590年和1594年的地图完善了欧洲人还没有到过美洲的西部和亚洲地理,比对中文的《坤舆万国全图》的准确性,唯一可能是西方采纳了来自中国的信息。其中最大可能是荷兰航海者林斯豪滕和他相熟的中国通在印度果阿的交流,果阿是郑和当年必经之地。1590年后,西方地图有了飞跃的发展,其后西方海洋霸权中心从葡萄牙转移到荷兰和英国。奥特里斯1570年的世界地图,普兰修斯1590年与1594年的世界地图,3种地图逐步改善了西方对新大陆和中国的认识,但是没有欧洲人测量的文献根据,应该是中国的世界地理知识传入西方。《乾坤万国全图天下人物事迹》《郑和航海图》与《坤舆万国全图》代表3种不同用途的地图,均为中国创绘。《坤舆万国全图》的原图是明代内府藏的世界地图,约1430年成图,远早于利玛窦和李之藻时代。明代中国人是世界地理大发现者,是现代地图学的先驱,地图学起码是中国独立创建的,不是来自西方。     

Impact‐induced hydrothermal activity within the Haughton impact structure,arctic Canada: Generation of a transient,warm, wet oasis

Abstract— Field studies and analytical scanning electron microscopy indicate that a hydrothermal system was created by the interaction of water with hot, impact‐generated rocks following formation of the 24 km diameter, 23 Ma Haughton impact structure. Hydrothermal alteration is recognized in two settings: within polymict impact breccias overlying the central portion of the structure, and within localized pipes in impact‐generated concentric fault systems. The intra‐breccia alteration comprises three varieties of cavity and fracture filling: (a) sulfide with carbonate, (b) sulfate, and (c) carbonate. These are accompanied by subordinate celestite, barite, fluorite, quartz and marcasite. Selenite is also developed, particularly in the lower levels of the impact breccia sheet. The fault‐related hydrothermal alteration occurs in 1–7 m diameter subvertical pipes that are exposed for lengths of up 20 m. The pipes are defined by a monomict quartz‐carbonate breccia showing pronounced Fe‐hydroxide alteration. Associated sulfides include marcasite, pyrite and chalcopyrite. We propose three distinct stages in the evolution of the hydrothermal system: (1) Early Stage (>200 °C), with the precipitation of quartz (vapor phase dominated); (2) Main Stage (200‐100 °C), with the development of a two‐phase (vapor plus liquid) zone, leading to calcite, celestite, barite, marcasite and fluorite precipitation; and (3) Late Stage (<100 °C), with selenite and fibroferrite development through liquid phase‐dominated precipitation. We estimate that it took several tens of thousands of years to cool below 50 °C following impact. During this time, Haughton supported a 14 km diameter crater lake and subsurface water system, providing a warmer, wetter niche relative to the surrounding terrain. The results reveal how understanding the internal structure of impact craters is necessary in order to determine their plumbing and cooling systems.     

Characteristics of sea breeze front development with various synoptic conditions and its impact on lower troposphere ozone formation

To examine the correlation between the sizes of sea breeze fronts and pollutants under the influence of synoptic fields, a numerical simulation was conducted in the southeast coastal area of the Korean Peninsula, where relatively high concentrations of pollutants occur because of the presence of various kinds of industrial developments. Sea breeze and sea breeze front days during the period 2005-09 were identified using wind profiler data and, according to the results, the number of days were 72 and 53, respectively. When synoptic forcing was weak, sea breeze fronts moved fast both in horizontal fields and in terms of wind velocity, while in the case of strong synoptic forcing, sea breeze fronts remained at the coast or moved slowly due to strong opposing flows. In this case, the sea breeze front development function and horizontal potential temperature difference were larger than with weak synoptic forcing. The ozone concentration that moves together with sea breeze fronts was also formed along the frontal surfaces. Ozone advection and diffusion in the case of strong synoptic forcing was suppressed at the frontal surface and the concentration gradient was large. The vertical distribution of ozone was very low due to the Thermal Internal Boundary Layer (TIBL) being low.     

中国地震区域划分圖及其說明 Ⅰ.总的說明

为国家工業建設地点提供地震参考資料,和全国地震危險地区的划分,是中国科学院地球物理研究所解放以来重点工作之一,承各方面的协助,笔者和徐煜坚等九人在苏联顧問帮助下編成了我国的“全国地震区域划分圖”。現在提出,作簡单的說明,請讀者提意見,以便作进一步的修正。     

离心场中土体图像采集与位移测量系统的研制与应用

以存储前移为主要思路,开发了离心场中高质量图像高速采集与位移非接触测量系统。该系统由图像采集、数据存储、通讯控制、分析处理和辅助制样5个子系统组成,能够克服高速旋转的离心场的干扰,在离心模型试验过程中高速采集高质量图像。该系统能够对多点同时进行测量,从而得到土体表面任意时刻、任意区域的位移场,并具有对土体无干扰、测量精度高、前期准备工作量小、自动化程度高等优点。使用该系统对土坡破坏离心模型试验中的土坡变形过程进行了测量,结果表明,土坡的破坏过程可分为均匀变形、应变局部化和破坏后变形3个阶段,加载过程中首先在坡顶和坡脚产生应变局部化。