Impact of a Tropical Cyclone on Coastal Upwelling Processes

A three-dimensional numerical model is described to study theresponse of a coastal ocean excited by a tropical cyclone in the Bay of Bengal. The numericalexperiments have been carried out using the model to understand the dynamics and thermodynamics ofthe ocean due to different cyclonic systems approaching in different directions. In the firstexperiment, the model is used to simulate the vertical thermal structure of the ocean as a response ofpassage of the less intensified 1997 cyclone, which was skirting the east coast of India before crossingthe Bangladesh coast. The simulations are compared with the buoy data available during the storm period.In the next experiment, it is considered an idealized cyclone with hurricane winds movingnormal to the east coast of India crossing between Visakhapatnam and Kakinada to evolve thermalstructure and currents of the ocean. A net decrease of the SST of 6–7 °C is simulated whenthe severe cyclonic storm moved over the coastal ocean.     

孟湾槽在百色市异常降雪天气中的作用

通过对1983年12月28日、2002年12月26日百色市两次异常降雪天气过程的对比分析,发现冬季孟加拉湾槽的发展东移在其中起到了关键性的作用。由于孟加拉湾槽前暖湿气流强盛,这种强盛的西南暖湿气流在低空冷空气堆(冷锋)上发生强烈的系统性上升运动,从而导致百色市及其邻近地区出现异常的雨雪天气。     

Potential toxicity of resuspended particulate matter and sediments: Environmental samples from the Bay of Banyuls-sur-Mer and Thermaikos Gulf

This contribution attempts to determine whether, and to what degree, environmental samples of resuspended particulate matter and sediments exert a toxicological impact. Further, an attempt is made also to screen the toxic level of potentially hazardous sites, based upon established sediment toxicity criteria. Therefore, a rapid, cost-effective and highly sensitive biotest (bioluminescence assay, based upon marine bacteria) has been applied on: biological fluid extracts; bottom sediments; and sediment trap samples. Samples were taken either from the Bay of Banyuls-sur-Mer (northwestern Mediterranean, France) or Thermaikos Gulf (northeastern Mediterranean, Greece). Biological fluid extracts and sediment trap samples corresponded to periods of resuspension events, or preceding and following such events.The results have revealed that the sampling strategy and biotest implemented in this study might be a useful tool for screening the toxicity of resuspended matter and sediments. Resuspension events appear to be able to exert an influence on the chemical forms of the micro-pollutants; thus on their bioavailability and toxicity. Nevertheless, based upon chemical analysis combined with the bioassay, the toxic level of the sediment samples could be determined, with the level at potentially hazardous sites being characterised.     

浙江象山港岛屿春、夏季潮间带大型底栖生物的群落结构特征

基于2015年4月(春季)和6月(夏季)象山港主要岛屿潮间带大型底栖生物的生态调查数据,采用优势度、生物多样性指数、次级生产力、聚类、多维尺度排序及丰度/生物量比较曲线等方法,分析了主要岛屿潮间带大型底栖生物的群落特征和季节变化。结果表明:(1)春、夏季共鉴定出大型底栖生物52种,其中底栖动物与底栖藻类各有45和7种,春、夏季共有物种数为34种,短滨螺、中间拟滨螺、齿纹蜒螺、青蚶等11种为春、夏季共有优势种;(2)夏季平均丰度(2074.85g/m²)高于春季(1505.01g/m²),春季平均生物量和次级生产力(2373.75ind./m²,16.31g/(m²·a))高于夏季(2210.17ind./m²,12.17g/(m²·a));(3)春季Shannon-Weiner多样性指数和Pielou’sevenness均匀度指数(2.742,1.679)高于夏季(2.580, 1.623),夏季Margalef丰富度指数(0.716)高于春季(0.667...     

莱州湾南岸第三陆相层年龄的铀系等时线法(TSD)测定

于莱州湾南岸ZK32-1钻孔第三陆相层上下边界处选取自生钙质结核,采用样品全溶铀系等时线法(TSD法)测定钙质结核的年龄。测试结果表明,所有等时线上的数据都有很好的线性关系,表明所获得的年龄数据是合理的。通过对样品代表性的讨论,说明所选取的钙质结核的年龄确可代表其所在地层的年龄,从而得出莱州湾南岸第三陆相层的沉积起止时间为72.16ka B.P.±7.41ka B.P.到45.34ka B.P.±5.35ka B.P.的结论。本研究首次获得莱州湾南岸地层的铀系TSD年龄,为全面认识该地区晚更新世地层年代学提供了一个新视角。     

The investigation on particulate organic carbon fluxes with disequilibria between thorium-234 and uranium-238 in the Prydz Bay, the Southern Ocean

Dissolved and particulate thorium-234, particulate organic carbon in the upper 150 m of water columns from five stations in the Prydz Bay, the Southern Ocean were determined during the 22nd Chinese National Antarctic Research Expedition （from November 2005 to March 2006 ）. The disequilibria between thorium-234 and its parent uranium-238 in upper layer was used to derive the averaged residence time of thorium-234, which decreased along with the latitude to the south and a minimum value, 1 - 8 d for particulate thorium-234 and 29 - 48 d for dissolved thorium-234, appeared at the medium latitude station, and the export fluxes of thorium-234 were calculated too and ＇a maximum value, 0. 35 -0. 63 Bq/（m^3 · d） for the particulate thorium-234 and 0. 44 -0. 65 Bq/ （m^3 ·d） for the dissolved thorium-234, appeared at the same station. The export fluxes of particulate organic carbon at different water columns were derived by two methods with irreversible scavenging model, and the averaged values were 104. 7 mmol/ （ m2 · d ） （ E method） and 120. 6 mmol/（ m2·d ） （ B method ）, respectively, indicating that a relatively high new production would exist in summer in the Prydz Bay where it will play a potential significant role in sequestering the absorption CO2 to deeper ocean.     

胶州湾李村河口沉积物中硫化物形成的控制因素

在胶州湾李村河口,对多个短柱状岩芯沉积物中的有机质（有机碳和有机氮）、酸可挥发性硫化物（AVS）、黄铁矿及活性铁等进行了分析。结果表明,样品的有机质含量较高,有机碳含量为0．16％～3．21％,有机氮含量为0．002％-0．2％;6个短柱状样的AVS含量变化较大：198．4—0．4umol／g,平均35．6umol／g;活性铁含量为47．5～169．3umol／g,平均91．4umol／g;黄铁矿含量为14．8～41．0umol／g,平均28．7umol／g。通过计算沉积物中活性铁的黄铁矿化度（DOP）与硫化度（DOS）指标,及分析各参数间相关性,发现以下现象：（1）胶州湾李村河口沉积物中的活性铁被转化为硫化物的程度较高,被转化为黄铁矿的程度较低,沉积物中的黄铁矿得到了较好保存。DOP不适宜用作河口区氧化还原状态的判断指标,DOS对氧化还原状态的响应更加灵敏;（2）距河口较近的区域,受李村河河水的影响较大,易分解有机质供应充足,AVS大量形成,其向黄铁矿的转化并不充分,活性铁成为硫化物形成的控制因素。距河口较远的站位,活性铁含量相对充足,有机质含量相对不足,因此有机质含量成为硫化物形成的控制因素,AVS向黄铁矿的转化比较充分;（3）有机质尤其是易分解有机质含量是李村河口硫化物形成、活性铁富集及其黄铁矿化度的主要控制因素。AVS的形成主要受到有机氮的限制,而黄铁矿的形成主要受到有机碳的限制。因此,河流输入物质对河口区沉积物中C、S和Fe的循环具有显著的影响。     

中国东部断陷湖盆细粒沉积岩岩相划分方案探讨——以渤海湾盆地南部古近系细粒沉积岩为例

细粒沉积岩岩相研究是烃源岩和页岩油、致密油储层研究的重要基础,鉴于我国陆相断陷湖盆环境多变和细粒沉积岩类型多样、岩石组合类型复杂的特点,需要进行细粒沉积岩岩相分类。以渤海湾盆地南部古近系细粒沉积岩发育段为研究对象,通过厘米级岩芯观察描述、岩石薄片鉴定、激光共聚焦显微镜观察分析等技术,研究细粒沉积岩基本特征。陆相断陷湖盆细粒沉积岩岩相划分可以按照(1)宏观岩芯精细观察描述,归纳垂向岩石类型组合;(2)分析沉积微环境;(3)对不同岩石类型组合进行X射线全岩矿物衍射和TOC测试,划分岩石类型和岩相大类;(4)微观镜下剖析纹层叠置关系;(5)分析成因和形成机制,对岩亚类细分等5步进行。岩相大类划分要简洁,是为满足油田勘探工作易于操作、建立与常规测井资料之间关系等要求;亚类细分是便于研究微观源储关系、分析沉积微环境和储层微观结构等。     

渤海湾盆地辽东湾地区古近系地震相研究

对辽东湾地区古近系地层进行了研究,选择了可信度较高的地震反射内部结构和外部形态,辅助地震反射振幅、连续性等参数,对地震相进行了划分命名。在研究区6个地震层序中共识别出平行—亚平行席状地震相、前积地震相、楔状地震相、充填状地震相、透镜状地震相、丘状地震相及乱岗状地震相等多种类型。这些地震相在平面分布上具有差异性,在垂向演化上具有继承性。将地震相转变为沉积相,划分出了湖泊沉积环境的深湖—半深湖、滨浅湖、扇三角洲、近岸水下扇、三角洲、浊积扇等沉积相,预测出了有利沉积相带。     

孟加拉湾晚第四纪的碳酸盐溶解旋回

孟加拉湾由于陆源物质大量输入产生稀释效应,使碳酸盐含量表现为冰期时减小、间冰期时增大的“大西洋型”旋回。通过对该区四支活塞岩芯的有孔虫溶解指数、浮游有孔虫沉积通量、CaCO₃ 沉积通量和 >16 0 μm粗组分沉积通量的分析发现,研究区碳酸盐溶解作用强烈,表现出冰期减弱而间冰期增强的总趋势,且溶解作用滞后于浮游有孔虫壳的氧同位素旋回,尤以氧同位素 4、5期的高溶解度情况与印度洋和太平洋氧同位素 5期晚期至 4期为CaCO₃溶解高峰一致。因此,孟加拉湾地区的CaCO₃ 旋回是大西洋型稀释作用与太平洋型溶解作用两者叠加的产物.