一个重构的153年热带太平洋次表层上卷海温资料

次表层上卷海温对改进ENSO(厄尔尼诺-南方涛动,El Ni o-Southern Oscillation)模拟水平及ENSO年代际变化均具有重要作用。利用一个中等复杂程度耦合模式(intermediate coupled model,简称ICM)和Nudging(张弛逼近)同化方法,重构了1856—2008年间热带太平洋地区的次表层上卷海温。统计检验表明,重构的次表层上卷海温与近50年的3种分析资料间具有较高的相关性和较小的均方根误差。此外,通过此重构的次表层上卷海温资料重新驱动ICM模式,模拟得到的海表温度距平(sea surface temperature anomaly,简称SSTA)可以真实地反映出ENSO的年际和年代际变化,表明此重构的次表层上卷海温资料可用于气候研究,特别是用于ENSO的大尺度低频变化或年代际气候变化研究。     

Susceptibility assessment of earthquake-triggered landslides in El Salvador using logistic regression

This work has evaluated the probability of earthquake-triggered landslide occurrence in the whole of El Salvador, with a Geographic Information System (GIS) and a logistic regression model. Slope gradient, elevation, aspect, mean annual precipitation, lithology, land use, and terrain roughness are the predictor variables used to determine the dependent variable of occurrence or non-occurrence of landslides within an individual grid cell. The results illustrate the importance of terrain roughness and soil type as key factors within the model — using only these two variables the analysis returned a significance level of 89.4%. The results obtained from the model within the GIS were then used to produce a map of relative landslide susceptibility.     

Long bone histology of a eusuchian crocodyliform from the Upper Cretaceous of Spain: Implications for growth strategy in extinct crocodiles

The long bone histology of a Late Cretaceous eusuchian crocodyliform from the Iberian Peninsula reveals clear variations in the cortical structure which reflects changes in the speed of bone deposition (i.e., skeletal growth) related to ontogeny. The presence of secondary woven-fibred bone tissue in the perimedullar region of the cortex, and the existence of an external fundamental system in the most external periostic cortex, which is a proxy for somatic maturity and effective cessation of growth, challenges the former idea that the growth strategy of extinct crocodylians fit in the typical ectotherm condition, according to which these animals grew slowly during life under an indeterminate growth strategy. The analysed specimen lived for a minimum of 16 years and the highest preserved apposition rates took place in an advanced ontogenetic stage. The study suggests that the general aspects of the modern crocodylian growth strategy were already in place in some lineages by the Cretaceous.     

不同强度El Nino的衰减过程.Ⅰ,强El Nino的衰减过程

将1951～2004年期间的12次El Nino事件分为强、中等、较弱和弱4类,结果发现,强和较弱El Nino衰减进入La Nina,但是中等和弱El Nino衰减进入平常态.因此,El Nino的衰减结果与自身强度之间存在密切的非线性关系.进一步的研究表明,负异常信号自西太平洋向中东太平洋的东传主导了强El Nino事件向La Nina的转变过程,其具体动力过程类似于西太平洋振子理论.热带西北太平洋（WNP）大气异常反气旋在强El Nino位相转变中起核心作用,它的维持和缓慢东移是赤道东风异常维持和发展的原因,而后者通过激发Kelvin波导致了ENSO从El Nino向La Nina的转变.     

The influence of El Niño-Southern Oscillation (ENSO) cycles on wave-driven sea-floor sediment mobility along the central California continental margin

Ocean surface waves are the dominant temporally and spatially variable process influencing sea floor sediment resuspension along most continental shelves. Wave-induced sediment mobility on the continental shelf and upper continental slope off central California for different phases of El Niño-Southern Oscillation (ENSO) events was modeled using monthly statistics derived from more than 14 years of concurrent hourly oceanographic and meteorologic data as boundary input for the Delft SWAN wave model, gridded sea floor grain-size data from the usSEABED database, and regional bathymetry. Differences as small as 0.5 m in wave height, 1 s in wave period, and 10° in wave direction, in conjunction with the spatially heterogeneous unconsolidated sea-floor sedimentary cover, result in significant changes in the predicted mobility of continental shelf surficial sediment in the study area. El Niño events result in more frequent mobilization on the inner shelf in the summer and winter than during La Niña events and on the outer shelf and upper slope in the winter months, while La Niña events result in more frequent mobilization on the mid-shelf during spring and summer months than during El Niño events. The timing and patterns of seabed mobility are addressed in context of geologic and biologic processes. By understanding the spatial and temporal variability in the disturbance of the sea floor, scientists can better interpret sedimentary patterns and ecosystem structure, while providing managers and planners an understanding of natural impacts when considering the permitting of offshore activities that disturb the sea floor such as trawling, dredging, and the emplacement of sea-floor engineering structures.     

Removal of Ni(II) from Aqueous Solutions by Nanoscale Magnetite

Magnetite nanoparticles were applied to remove Ni(II) from aqueous solutions as a function of pH, contact time, supporting electrolyte concentration, and analytical initial Ni(II) concentration. The highly crystalline nature of the magnetite structure with diameter of around 10 nm was characterized with transmission electron microscopy (TEM) and X‐ray diffractometry (XRD). The surface area was determined to be 115.3 m²/g. Surface chemical properties of magnetite at 25°C in aqueous suspensions were investigated. The point of zero charge (pHzpc) was found to be 7.33 and the intrinsic acidity constants (${\rm p}K_{{\rm a}1}^{{\rm s}} $ and ${\rm p}K_{{\rm a}2}^{{\rm s}} $ ) were found to be 9.3 and 5.9, respectively. The surface functional groups were investigated with Fourier transform‐infrared spectroscopy (FTIR) as well. Batch experiments were carried out to determine the adsorption kinetics and mechanism of Ni(II) by these magnetite nanoparticles. The adsorption process was found to be pH dependent. In NaCl solutions, Ni(II) adsorption increased with increasing ionic strength while in NaClO₄ solutions, Ni(II) adsorption exhibited little dependence on the ionic strength of the solution. The adsorption process better followed the pseudo‐second order equation and Freundlich isotherm.     

沁水盆地煤系地层页岩气储层特征及评价

沁水盆地是我国重要的含煤盆地,不仅其煤炭及煤层气资源丰富,在上古生界石炭纪-二叠纪地层中还有大量页岩发育。而目前,针对该地区页岩地层的相关研究极少,该地区页岩气资源是否具有勘探开发潜力有待深入而细致的研究。本文以沁水盆地上古生界石炭系-二叠系海陆交互相页岩储层为研究对象,通过薄片鉴定、X线衍射分析、氩离子抛光扫描电镜分析、核磁共振、氦气吸附等实验方法,研究了富有机质页岩储层有机质含量、类型、成熟度等有机地化特征以及储集空间类型、物性、矿物组成、孔隙结构等储层特征。在此基础上,对研究区页岩储层的勘探开发潜力进行了评价。结果表明：沁水盆地石炭纪-二叠纪富有机质页岩储层中发育形态各异的不同类型孔隙及微裂缝。其中,矿物基质孔十分发育,主要包括有呈片状、三角形及不规则形态的粒间孔和晶间孔等;而有机质孔不发育,呈点状,偶见椭圆型。从孔隙结构上看,孔隙具有较大的比表面积,主要分布在2.84~6.44 m2/g,平均值为4.26 m2/g。平均孔径分布在3.64~10.34 nm,以中孔隙发育为主。从矿物组成来看,各矿物含量比例适中,黏土矿物含量较高,达到57.5%,有利于微孔隙发育和页岩气的吸附;以石英及长石为代表的脆性矿物含量较高,达到41.3%,易于后期压裂造缝。从有机地化特征来看,有机碳含量高,有机质类型以腐泥腐殖型为主,且受中生代异常地温场控制,有机质热成熟度高,有利于页岩气的生成和吸附存储。总体来说,虽然研究区石炭纪-二叠纪页岩储层埋深浅,但有机地化参数、矿物组成、孔隙发育及结构特征都有利于页岩生烃和页岩气储存,具有较大的勘探与开发潜力。     

GEOGRAPHY AND THE LESSONS FROM EL NIÑO∗

Recognized for years as a major environmental disruption, El Niño generated intense public interest in 1982–1983. During its last occurrence, this phenomenon, which develops in the tropical Pacific and usually affects rimlands of the Pacific basin, exceeded its boundaries and its effects were transmitted to continental North America, Europe, Africa and East Asia. Notwithstanding its vast areal extent, the interest of geographers in El Niño events, past and recent, has been comparatively less than that demonstrated by natural scientists and ecologists: little has been accomplished to place these climatic-ecological crises within global perspective. Lessons from El Niño include the acknowledgement of new concepts of climatic transitivity, ocean dynamics and energy exchanges that must find a place within the conceptual wealth of geography if this science intends to keep up with the rapid progress of other geosciences.     

Erosive water level regime and climatic variability forcing of beach–dune systems on south‐western Vancouver Island,British Columbia,Canada

Increases in the frequency and magnitude of extreme water levels and storm surges are correlated with known indices of climatic variability (CV), including the El Niño Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO), along some areas of the British Columbia coast. Since a shift to a positive PDO regime in 1977, the effects of ENSO events have been more frequent, persistent, and intense. Teleconnected impacts include more frequent storms, higher surges, and enhanced coastal erosion. The response of oceanographic forcing mechanisms (i.e. tide, surge, wave height, wave period) to CV events and their role in coastal erosion remain unclear, particularly in western Canada. As a first step in exploring the interactions between ocean–atmosphere forcing and beach–dune responses, this paper assembles the historic erosive total water level (TWL) regime and explores relations with observed high magnitude storms that have occurred in the Tofino‐Ucluelet region (Wickaninnish Bay) on the west coast of Vancouver Island, British Columbia, Canada. Extreme events where TWL exceeded an erosional threshold (i.e. elevation of the beach–foredune junction) of 5·5 m aCD are examined to identify dominant forcing mechanisms and to classify a regime that describes erosive events driven principally by wave conditions (61·5%), followed by surge (21·8%), and tidal (16·7%) effects. Furthermore, teleconnections between regional CV phenomena, extreme storm events and, by association, coastal erosion, are explored. Despite regional sea level rise (eustatic and steric), rapid crustal uplift rates have resulted in a falling relative sea level and, in some sedimentary systems, shoreline progradation at rates approaching +1·5 m a^–1 over recent decades. Foredune erosion occurs locally with a recurrence interval of approximately 1·53 years followed by rapid rebuilding due to high onshore sand supply and often in the presence of large woody debris and rapidly colonizing vegetation in the backshore. Copyright © 2012 John Wiley & Sons, Ltd.