Swashed away? Storm impacts on sandy beach macrofaunal communities     

Linda Harris  Ronel Nel  David Schoeman 《Estuarine, Coastal and Shelf Science》2011,94(3):210-221

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Short-term residence and movement patterns of the annular seabream Diplodus annularis in a temperate marine reserve     

David March  Josep Als  Amlia Grau  Miquel Palmer 《Estuarine, Coastal and Shelf Science》2011,92(4):251-587

The short-term movements of a small temperate fish, the annular seabream Diplodus annularis (Linnaeus 1758), were examined using standard tag-recapture and passive acoustic telemetry in Palma Bay (NW Mediterranean), a marine protected area (MPA). The study aimed to provide valuable information for assessing the recreational fishery and its results suggest that MPAs can be used to protect the adult stock of D. annularis. All the fish tagged with standard tags were recaptured near the release locations, with a maximum distance of ∼300 m. The maximum time between release and recapture was 185 d. Two different arrays of acoustic receivers were deployed, one in 2008 and another in 2009, within the MPA. Twenty adults were surgically tagged with acoustic transmitters. Fish monitored in 2008 (n = 12) were translocated from the point of capture to analyse the movement behaviour after artificial displacement. Upon release at displaced locations, 67% of the fish moved towards the original capture location using a time of return that ranged from 0.75 to 15.25 h. Fish monitored in 2009 (n = 8) were released at the point of capture. They showed high site fidelity with a maximum period of 27 d between the first time and the last time they were detected.  相似文献   

珠江三角洲城市群对夏季降雨影响的初步研究   总被引：5，自引：4，他引：1  

任慧军  徐海明 《气象科学》2011,31(4):391-397

利用TRMM 2A25卫星降水数据和CMORPH同化数据对珠三角洲地区的降水分布特征进行了探讨,观测表明：珠三角城市群区域总体处于降水的低值中心,且对流降雨的低值中心尤为明显;同时近10 a珠三角核心城市区域降雨有减少的趋势,这种降水减少的趋势可能与珠三角城市化效应有关。本文进一步利用WRF模式模拟分析了珠三角城市群发展对夏季降雨的影响,结果表明珠三角城市化使得该区域降雨减少,其原因为城市化使得地表的蒸发减弱及其大气中的水分供应减少,同时也抬升了珠三角区域边界层高度相应增强了低层大气水汽垂直混合。  相似文献   

Do paleoclimate proxies agree? A test comparing 19 late Holocene climate and sea‐ice reconstructions from Icelandic marine and lake sediments     

Yarrow Axford  Camilla S. Andresen  John T. Andrews  Simon T. Belt  Áslaug Geirsdóttir  Guillaume Massé  Gifford H. Miller  Sædís Ólafsdóttir  Lindsay L. Vare 《第四纪科学杂志》2011,26(6):645-656

Geochemical, mineralogical and biological indicators preserved in sediments are widely used to reconstruct past climate change, but proxies differ in the degree to which their utility as climate indicators has been validated via laboratory experiments, modern spatial calibrations, or down‐core comparisons with instrumental climate data. Multi‐proxy studies provide another means of evaluating interpretations of proxies. This paper presents a multi‐proxy assessment comparing 19 sub‐centennially resolved late Holocene proxy records, covering the period 300–1900 AD, from seven Icelandic marine and lacustrine core sites. We employ simple statistical comparisons between proxy reconstructions to evaluate their correlations over time and, ultimately, their utility as proxies for regional climate. Proxies examined include oxygen isotopic composition of benthic and planktonic foraminifera, abundance of the sea‐ice biomarker IP₂₅, allochthonous quartz in marine sediments (a proxy for drift ice around Iceland), marine carbonate abundance, total organic carbon concentration, chironomid assemblages, lacustrine biogenic silica and carbon/nitrogen ratios in lake sediments. Most of the examined proxy records, including temperature and sea‐ice proxies, correlate strongly with each other over multi‐centennial timescales, and thus do appear to record changes in regional climate. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

锦州25—1区块探井钻井实践与认识     

魏刚  ;刘小刚  ;陶林  ;张春琳 《海洋地质译丛》2009,(3):71-74

锦州25—1油田是渤海湾近年钻探发现的大型油田。锦州25—1区块先后钻了十多口探井，在钻井作业中遇到上部井眼扩大严重、井径不规则、井垮、起下钻遏阻卡、电测作业遏阻、电测井底沉砂较多、井漏等复杂情况。通过对锦州25—1区块前面几口探井钻井中出现的问题进行认真分析，研究了锦州25—1区块的地层压力剖面分布。经过不断的总结与措施改进后，在后面的探井钻井作业中做到了起下钻顺利，上部井径扩大率较小，未出现井垮情况，电测一次到底，钻井作业生产时间大幅度提高，为锦州25—1油田的生产井钻井积累了宝贵的经验。  相似文献   

济阳拗陷特殊生物降解油的初步研究   总被引：1，自引：1，他引：0  

卢鸿  彭平安  徐兴友  张林晔 《沉积学报》2004,22(4):694-699

济阳拗陷草古100平19井奥陶系储层原油,饱和烃馏分均已损失殆尽,仅残余藿烷系列化合物;同时,芳烃馏分化合物也已损失殆尽,仅残余三芳甾烷系列化合物。上述芳烃化合物俱已损失殆尽的蚀变特征,在相关文献中的报道较为少见。原油中不受水洗作用影响的正构烷烃和不受生物降解作用影响的有机硫化合物(苯并噻吩和二苯并噻吩)均已损失殆尽,显然暗示了原油蚀变是遭受水洗作用和生物降解作用共同作用的结果。原油芳烃馏分的“UCM”鼓包幅度明显大于饱和烃馏分的“UCM”鼓包,暗示了芳烃化合物的降解速率平行甚至超过饱和烃的降解速率。原油中低分子量芳烃化合物的快速降解,暗示了油藏可能是在氧化条件下而非在还原条件下发生蚀变的。  相似文献   

准噶尔盆地中部III 区块原油中25-降藿烷分布特征与成因意义          下载免费PDF全文

秦黎明  张枝焕  李伟  杨永才  袁东山 《地球学报》2008,29(4):478-485

通过对准噶尔盆地中部Ш区块原油或油砂抽提物的饱和烃气相色谱-质谱分析,研究了原油或油砂抽提物中25-降藿烷的分布规律.结果表明,不同井区或同一口井不同深度(层位)的原油25-降藿烷的相对含量存在比较明显的差别,表明其所遭受的生物降解程度有所差异,沿构造带从南到北,同一油层中原油的生物降解程度增强,比如位于构造北部(构造部位相对较高)的永1井、永3井侏罗系原油25-降藿烷丰度较高,表明生物降解比较明显,而位于南部(构造低部位)的永6井白垩系和侏罗系油层中的原油均无明显的生物降解现象;同一口井随深度增大生物降解作用将弱,如永2井浅部白垩系油层的原油降解较严重,而深部西山窑组的原油降解作用则不明显.根据原油生物降解的特征,结合车-莫古隆起调整对研究区油气成藏的影响,讨论了原油生物降解差异分布的成因机制.  相似文献   

新疆25号泉震兆异常特征的初步分析     

地里夏提·克优木  朱成英  王中道 《内陆地震》2005,19(3):278-281

通过对新疆沙湾25号泉1991年以来的水温和硫化物总量的系统分析,发现该观测点对其周围约300 km范围内的5级以上中强地震有一定震兆异常反映,尤其是观测点附近的地方震往往表现为大幅度异常.  相似文献   

台湾费丛峡谷对强地面运动的影响研究──利用单台资料及2．5维SH混合方法     

温联星  姚振兴 《地球物理学报》1995,38(1):64-70

本文通过格林函数反褶积方法，由台湾峡谷附近的记录资料预测峡谷区的强地面运动的时程曲线．峡谷区的理论格林函数应用２．５维ＳＨ混合方法求解．通过格林函数反褶积方法得到的峡谷区费丛１及费丛２台的位移、速度、加速度和实际资料对比，取得了满意结果．计算结果表明，峡谷底部的峰值加速度相对峡谷边缘为最小；在靠近震中的一侧，峡谷的加速度的最大振幅相对比另一侧大．还给出了其余３个台的预测结果，研究了它们的加速度傅里叶谱和反应谱．  相似文献   

四川省地县分组交换网系统的设置和安装     

向继涛  缪贵平 《高原山地气象研究》2002,22(2)

介绍了四川我省地(市)县气象局通过X.25网络连接交换数据其服务器端和客户端x.25卡设置和操作系统有关参数的调整.  相似文献