Evaluation of geochemical impact of tsunami on Pichavaram mangrove ecosystem,southeast coast of India   总被引：1，自引：0，他引：1  

Rajesh Kumar Ranjan  AL. Ramanathan  Gurmeet Singh 《Environmental Geology》2008,55(3):687-697

The 26 December 2004-tsunami has deposited sediments in the Pichavaram mangrove ecosystem, east coast of India. Ten surface and three core sediment samples were collected within 30 days of the event and analyzed for nutrients. Water samples were also analyzed to see the impact of tsunami on the geochemical behavior of nutrients. An increase in the concentration of various nutrients namely nitrate and phosphate was observed. The geochemistry of the mangrove forest was observed to be influenced by a number of factors like rapid increase of aquaculture farms, agricultural practices and the anthropogenic discharge from the nearby-inhabited areas. Further the sediment column was disturbed due to energetic tsunami waves, which has caused a sheer increase in the dissolved oxygen in water. As a result, the change in the redox potential has resulted in change in the nutrients absorbed/associated with the sediments. In addition, role of retreating water after tsunami on the nutrient geochemistry was also evaluated.  相似文献   

藏南地区中生代硅质岩的地球化学特征及其成因意义   总被引：6，自引：1，他引：5  

周永章  付伟  杨志军  何俊国  聂凤军  李文  赵文霞 《岩石学报》2008,24(3)

藏南地区中生代硅质岩包括蛇绿岩套硅质岩(与蛇绿岩共生)和非蛇绿岩套硅质岩两大类.本文重点分析日喀则地区彭错林、夏鲁以及泽当地区的罗布莎、江孜盆地宗卓组及四个剖面的硅质岩.其中,彭错林、夏鲁和罗布莎硅质岩与蛇绿岩共生,江孜盆地宗卓组为非蛇绿岩套硅质岩.分析表明:(1)藏南地区硅质岩剖面地球化学特征鲜明,具有一致性和多样性特点;(2)与蛇绿岩共生的彭错林、夏鲁、罗布莎硅质岩普遍具有高Si、高Fe、低Al特征,大部分微量元素相对于克拉克值亏损,稀土元素总量低,经北美页岩标准化后,Ce异常明显或不明显,重稀土相对轻稀土富集.硅质泥岩的∑REE要明显高于硅质岩;(3)非蛇绿岩套宗卓组硅质岩SiO2含量稍低,Al2O3、TiO2则相反.V、Th、Hf、Ta等不相容元素上亏损程度较小,部分样品含量可接近克拉克值.稀土总量相对较高,页岩标准化配分模式上体现为弱Ce正异常,负Eu异常,轻重稀土分异不明显的平坦型曲线图;(4)地球化学特征指示了,藏南地区硅质岩多数具有明显的热水沉积成因属性,同时有正常陆源组分的加入.其中,夏鲁硅质岩的热水沉积地球化学特征较为典型,而宗卓组硅质岩则表现出受陆源物质加入的影响显著的地球化学特点.  相似文献   

吕宋冷涡时空特征概况   总被引：1，自引：0，他引：1  

刘金芳  毛可修  闫明  张绪东  石永军 《海洋预报》2006,23(2):39-44

本文在收集南海以及台湾周边海域1900~2004年共105a的海洋调查资料,按0.5°×0.5°网格进行温盐计算统计分析,制作了逐月平面、断面分布图的基础上,参考相关文献和海洋水文图集,阐明了吕宋冷涡的空间、季节特点及其变化规律。中尺度涡对海洋科学、舰艇航行及国防建设等都有重要的学术意义和实际应用意义。  相似文献   

柴达木盆地昆特依盐湖的地球化学演化与古气候变化   总被引：9，自引：1，他引：9  

韩凤清  黄麒  王克俊  王华安  原力 《海洋与湖沼》1995,26(5):502-508

１９９０年用铀系年代学及古地磁对昆特依盐湖沉积物进行年代测定，探讨该湖区地球化学演化与古气候变化关系。结果表明，该区最老的盐层形成于早更新世晚期（大于７３０ｋａ），大量的盐类沉积则始于３００ｋａ左右；盐湖沉积物中元素含量变化主要受古盐度、矿物、类质同象和吸附控制；沉积物水溶Ｆ／Ｃｌ比值与古盐度成反比关系；该湖２０００ｋａ以来的古环境演变：盐层形成于干冷、偏酸性的氧化环境，泥岩层形成于湿暖、偏碱性的  相似文献   

鳗弧菌(Vibrio anguillarum)M3菌株生长条件及其对蛋白酶产量的影响   总被引：2，自引：5，他引：2  

陈师勇  张培军  莫照兰  邹玉霞  张振冬  徐永立 《海洋与湖沼》2004,35(2):159-166

采用体外测定细菌浓度、胞外产物(ECP)蛋白含量和蛋白酶活力的方法，进行了鳗弧菌M3菌株在2216E培养基中的培养条件研究。结果表明，该菌株用固体培养基培养至24h左右，可得到较高的菌体浓度、ECP蛋白含量和蛋白酶活力。采用响应面分析方法设计实验，用SAS统计软件分析数据，得到NaCl浓度、pH值和温度对菌体生长及蛋白酶产量影响的回归模型。在2216E培养基的基础上，添加不同氮源、碳源物质以及不同浓度蛋白胨进行生长研究。结果表明，胰大豆蛋白胨能促进菌体生长及ECP蛋白分泌；NH4Cl与酪蛋白水解物可抑制蛋白酶的产生；牙鲆肌肉匀浆对菌体、ECP蛋白产量和蛋白酶产生有不同程度的促进作用；培养基中蛋白胨浓度为4％时菌体量与ECP蛋白含量达最高值，在蛋白胨浓度为2％时蛋白酶分泌量已稳定；1％的葡萄糖、蔗糖、甘油均能显著地提高菌体及ECP蛋白产量，却抑制了蛋白酶的产生。  相似文献   

黄河三角洲*暴雨雷达回波特征及临近预报   总被引：3，自引：0，他引：3  

张经珍  郝家学  金伟福 《海洋湖沼通报》2001,(1):8-12

本文利用1994－1998年东营站713数字化雷达回波资料结合高空、地面形势，对发生在黄河三角洲地区的33个暴雨日41个暴雨中尺度雷达回波系统特征及形成过程进行了总结，提出了暴雨临近预报的着眼点。在1999年的预报服务中，取得了良好的经济效益和社会效益。  相似文献   

进入渤海的热带气旋路径特点分析     

张晓慧  卢霞  陈金龙 《海洋预报》2003,20(4):1-4

热带气旋是夏季影响渤海的灾害性天气系统之一。其影响路径主要有三类，各类路径在影响时前期中高纬500hPa高空环流形势及夏季西太平洋副热带高压特征指数有显著差异。  相似文献   

Responses of carbon dioxide in western tropical Pacific to 1991~1993 ENSO event     

Ma Liming 《海洋学报(英文版)》1997,16(2):201-214

On the basis of the data of the partial pressure of CO₂ (P_CO2)and the concentration of the total dissolved CO₂(T_CO2) in surface water during the expeditions in Nov.-Dec. 1991, the world ocean circulation experiment (WOCE) and Oct. 1992-Mar. 1993, the tropical ocean-global atmosphere coupled ocean-atmosphere response experiment (TOGA COARE) in the western tropical Pacific and of the comparison with data from 1986 to 1990 TOGA expeditions and that from Japan Meteorological Agency, the response of CO₂ in surface water to ENSO event is proved. The CO₂ signals indicated that the air-sea system in the western and central tropical Pacific from 1991 to 1993, except for a short period in autumn of 1992, was in a strong state of ENSO.
The change of CO₂ in the floating stations near 2°S, 155°E from Nov. 1992 to Mar. 1993 reflected the change of currents, water mass and its thermal and salt content during the forming and developing of ENSO.  相似文献   

套子湾表层沉积物地球化学特征的研究     

程波 《海洋科学进展》1993,(4)

本文对套子湾表层沉积物中的pH、Eh、硫化物、氮、磷、有机质、铜、铅、锌、镉地球化学特征进行了分析研究.并讨论了如下几个关系:①与沉积类型之间的关系;②其相关性与环境的关系。③与矿物的关系;④与水和风等作用的关系;⑤与水化学的关系;⑥重点分析了表层沉积物中化学要素与生物的相互关系。这不仅为该湾的开发治理.生物养殖等提供科学依据.并进一步证明沉积物地球化学.在环境化学和生态学研究等方面的理论意义。  相似文献   

Dissolved titanium distributions in the Mid-Atlantic Bight   总被引：1，自引：0，他引：1  

Stephen A. Skrabal   《Marine Chemistry》2006,102(3-4):218-229

Although titanium is abundant in Earth's crust, its sources and distribution in the ocean are poorly understood. To elucidate its behavior, distributions of dissolved (< 0.2 μm) Ti were determined in surface waters and vertical profiles from the Mid-Atlantic Bight (MAB). Concentrations of Ti decreased from 390 pM at the Delaware Bay mouth to < 100 pM across the Delaware continental shelf. In vertical profiles, small increases in bottom waters suggest a possible flux of Ti from shelf sediments, consistent with previous reports of pore water enrichments of dissolved Ti in MAB sediments. Concentrations in surface waters of the outer shelf and slope ranged between 30 and 140 pM, with most values below 90 pM. Concentrations in a 1000 m vertical profile in the eastern Gulf Stream ranged between 110 and 280 pM, and showed a variable distribution attributed to the mixing of water masses in the outer MAB. A simple model of Ti sources to the MAB suggests that atmospheric deposition of dissolved Ti is comparable to net riverine contributions and therefore must be considered in applications of Ti as a tracer of oceanographic processes.  相似文献