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81.
北黄海獐子岛海域浮游动物群落年际变化   总被引:1,自引:0,他引:1  
本文比较了海洋普查期间(1959年1-12月)和2009-2010年獐子岛海域附近站位的浮游动物的种类组成、优势种、丰度、生物多样性,结果显示,北黄海区域浮游动物群落物种组成未发生较大的变化,在獐子岛海域以及整个北黄海,中华哲水蚤和强壮箭虫的优势种地位没有发生变化,细足法虫戎也一直出现且为冬春季的优势种;太平洋磷虾在2009-2010年獐子岛海域虽然全年均有出现,但是全年均不是优势种,而在1959年的獐子岛海域,作为优势种出现在4月和11月;1959年与2009年相较,腹针胸刺水蚤在春夏季优势种的地位被沃氏纺锤水蚤所取代。2009年浮游动物丰度(131.26 ind/m3)比1959年(78.90 ind/m3)高;浮游动物多样性指数(H')均在夏秋季高于冬春季节,且年平均多样性指数也有所提高。  相似文献   
82.
海南岛东南部潟湖台风事件沉积记录   总被引:4,自引:1,他引:3  
研究海岸潟湖沉积记录可恢复器测记录之前和史前时期热带气旋活动的频率和强度信息。本文试图通过分析潟湖沉积揭示南海北部地区的古台风活动信息,以海南岛东南部两个潟湖的钻孔沉积物为研究对象,选取沉积物粒度、有机质和碳酸盐含量等参数建立台风事件的鉴别指标,同时借助210Pb CRS计年模式确定了沉积物柱状样的沉积速率和年代序列,对海南岛东南部的古风暴活动进行了分析。结果显示,柱状岩心清晰地记录了海南省东南部过去350年期间的35次特大风暴潮事件。基于历史文献和沉积记录的风暴沉积事件恢复了近350年来的风暴活动历史,发现海南省东南部特大风暴事件频数与厄尔尼诺强度有显著关系,同时还可能受到太平洋涛动(PDO)、北大西洋涛动(NAO)和太阳黑子活动等多种气候因素的综合影响。本文研究表明,结合风暴沉积记录和历史文献资料可为恢复海岸带地区长时间尺度高分辨率的古风暴活动规律提供有效信息。  相似文献   
83.
This article examines technical aspects of the maritime boundary dispute between Bangladesh and Myanmar (the ‘Bay of Bengal case’). This dispute was the first maritime delimitation determined by the International Tribunal for the Law of the Sea (ITLOS). The 2012 decision was also the first time that a maritime boundary for the seabed and subsoil of the Exclusive Economic Zone (EEZ) and the extended continental shelf (ECS) was determined by international adjudication. This was also therefore the first time that detailed technical quantification of seabed areas within the EEZ and ECS was needed for achieving an equitable division of these maritime zones in an international forum. Following review of the principles of maritime delimitation on which the ITLOS reached its determination, this article analyzes the legal status and delimitation effect of St. Martin's Island. Concerning the question of whether the legal regimes of the EEZ and continental shelf should be treated differently in a single delimitation line, although the ITLOS determined that the legal regimes should not be distinguished in the present case, a different approach is proposed for future cases. The article identifies how quantitative modelling can be used to achieve an equitable boundary and proposes a model to adjust provisional equidistance lines in accordance with the complex geophysical rules prescribed for the outer limits of the ECS in Article 76 of the United Nations Law of the Sea Convention (LOSC).  相似文献   
84.
This paper reports on progress in developing a regional research and education strategy for Pacific Island countries and communities wishing to transition to a low carbon sea transport future. Sea transport is an absolute necessity for most such communities. All current services are fossil fuel based and are becoming increasingly unaffordable and unsustainable. The countries in the Pacific region are the most dependent on imported fossil fuels in the world, importing more than 95% of needs. Such dependency is having a crippling effect on national budgets and major impacts on key productive sectors. The region's transport issues are unique; small and vulnerable economies scattered at the ends of some of the longest transportation routes in the world and arguably the most challenging to maintain per capita and per sea mile. Alternatives to current fossil fuel powered sea transport have been almost totally ignored in recent regional and national debates and the issue has been largely invisible within the policy and donor strategy space at all levels despite concerted efforts over more than two decades to transition Pacific countries' electricity sector fossil fuel use. The University of the South Pacific has been collaborating with a network of stakeholders and knowledge partners since 2012 to advance this agenda, building off previous doctoral research and the resultant Sustainable Sea Transport Talanoa 2012. Prasad et al. (2013) set out the basis for a catalytic research program following from the consensually agreed outputs of SSTT 2012 and this paper records the progress made since.  相似文献   
85.
康波  林宁  徐文斌  王娜  刘庆群 《海洋通报》2017,36(5):585-593
海岛不仅具有很高的资源、生态和经济价值,而且对维护国家海洋权益具有重大意义。本文基于遥感和GIS技术,利用1982、1995、2006和2015年的Landsat卫星遥感影像,分析了近30年来长岛南五岛海岸线的时空变化特征。结果表明:1982年以来,长岛南五岛近30年的海岸线长度增加了9.54 km,海岸线呈向海推进趋势,平均推进速度为0.54 m/a。海岸线变化主要受人为因素的影响,变化比较大的岸段主要分布在南长山岛和北长山岛的西部,以养殖开发、填海造陆与港口建设为主。研究认为,海岸线的变化,将会导致诸如岸线侵蚀等环境问题,应注意合理开发、利用海岸线资源。  相似文献   
86.
以舟山本岛为研究单元,利用1995年,2005年和2015年的遥感影像,采用生态学分析、空间统计学分析、城市扩张指数等方法来探究舟山本岛滩涂围垦活动和城市用地扩张的特点,并分析两者之间的关联。结果表明:(1)在1995—2015年的20 a间,滩涂围垦的面积不断扩大。(2)1995—2005年的滩涂资源利用以近陆域的海涂为主,2005—2015年逐渐向浅海发展。(3)1995—2015年间,城市用地面积前10 a增长强度为0.53,增长速度为3.01 km2/a,后10 a增长强度为1.46,增长速度为8.11 km2/a。(4)舟山本岛的城市发展重心在20 a间经历了一个自西向东移动而后向北跳跃的过程,各区域间协同发展,使舟山本岛经济整体性和城市功能合理性得到提升。(5)滩涂围垦形成的土地与城市用地扩张之间存在着正相关关系,且从研究数据来看两者之间发生自然演替需要时间,大约为8~10 a,人工干预可以大幅缩短这个过程所需要的时间。  相似文献   
87.
Transition to low carbon sea transport is a logical response to the extreme dependency of the Pacific Islands region on imported fossil fuel, its significant vulnerability to the effects of climate change and the critical shipping needs of Pacific Island countries (PICs). Building on previous work in low carbon sea transport in the Pacific, this paper further considers the barriers to achieving such transition by assessing, through a ‘post-Paris Agreement’ lens, the Intended Nationally Determined Contributions (INDCs) submitted by PICs and contrasting these to the near total lack of investment and planning for low carbon transition in the transport sector with the parallel occurrence in the electricity sector where ~USD 2 billion of donor investment is deployed or queued despite electricity using only ~20% of fossil fuel across the region. Consistent with recent international studies, inadequate and inappropriate financing and policy have been identified as dominant transition barriers for low carbon sea transport development in PICs. This paper further examines the regional level barriers to policy development, and finds them inhibited by the silo nature of the major regional actors. The implications that the Paris Agreement has for climate financing to support the essential research and capacity development needed to underpin a successful low carbon sea transport transition strategy at any useful scale and speed are also considered in this paper.  相似文献   
88.
基于线粒体CO1基因的序列,对渔山列岛,大连獐子岛,南麂列岛,山东南隍城乡,舟山嵊泗5个野生群体的厚壳贻贝进行遗传多样性和遗传结构的分析。结果表明:在mt DNACO1基因同源片段上共检测到了39个多态位点,其中39个简约信息位点,无单突变位点,构成40个单倍型,群体遗传多样性水平为:渔山山东大连舟山南麂;然而单倍型多样性却是山东渔山南麂大连舟山。分子进化树和单倍型网络关系图构建结果显示:5个群体之间分为3个单倍型类群(A、B、C),其中A类群含15个单倍型,B类群含23个单倍型,C类群含2个单倍型(均为渔山列岛的单倍型),其中渔山列岛的单倍型在上述三个类群中都有分布。3个单倍型类群间的遗传距离为0.0099~0.0268。渔山列岛群体内遗传分化较为显著,其他4个群体间未检测到显著的遗传分化。  相似文献   
89.
葛毓柱  钟建华 《地质论评》2017,63(4):927-940
灵山岛早白垩灵山岛组发育丰富的软沉积物变形构造。野外踏勘船厂、灯塔和千层崖三个剖面,根据沉积外观可分为变形层段和非变形层段两个部分。软沉积物变形构造在变形层段和非变形层段均有发育。其中,变形层段中可见褶皱变形、变形层理及大型负载构造。非变形层段可见火焰构造、同沉积布丁构造和同沉积微断层。研究发现,变形层段软沉积物变形构造尺度大(厚度可至十多米,长度可至数百米),侧向连续性好;非变形层段软沉积物变形构造尺度小(厚度仅几个厘米),侧向连续性差。且变形层段和未变形层段厚度统计数据表明,变形层段软沉积物变形构造与砂岩厚度无必然联系,而非变形层段软沉积物变形构造多出现在粒序砂岩层底部或旋回砂岩层变厚过程中。沉积环境表明,非变形层段和变形层段为一深水低角度斜坡沉积产物。软沉积物变形构造发育形态和数量受到斜坡地形的控制。结合沉积环境及沉积特征分析,认为变形层段软沉积物变形构造触发机制为地震,而非变形层段软沉积物变形构造触发机制为负载作用。锆石测年数据表明灵山岛组与上覆流纹岩沉积时间相近,因此地震活动可能与岩浆侵入或早期火山喷发活动相关。此外,汇总早白垩世重要事件,发现灵山岛组沉积、变冷事件、恐龙迁移、海平面变化和同位素偏移具有时间一致性,因此推断这些事件可能共同对应了早白垩世一次与火山活动相关的短期灾难性事件(如早白垩世缺氧事件)。  相似文献   
90.
The Ediacaran BISF at Hormuz Island is a newly identified glaciogenic iron-salt deposit in the Tethyan margin of Gondwana. The BISF was formed by synchronous riftogenic A-type submarine felsic volcanism and evaporate deposition. The mineralization occurs in a proximal felsic tuff cone and jaspilitic distal zones and contains 1 million tonne of hematite-rich ore with an average grade of 58% Fe. The ore structure shows cyclicity of macrobandings, mesobandings and microbandings of anhydrite, halite, hematite and chert, which marks a new record in BIFs geohistory. The alteration minerals in the proximal and distal zones are actinolite, ripidolite, epidote, sericite, tourmaline, clinochlore, anhydrite and clay minerals. The occurrence of metamorphosed polygenetic bullet-shape dropstones in BISF attests that there was probably a continuous process of ice melting, episodic submarine volcanism and exhalative hydrothermal banded iron salt formation during the Late Ediacaran time. The non-metamorphosed Neoproterozoic stratigraphy, the presence of genus Collenia, U-Pb dating (558 ± 7 Ma) and the marked negative δ13C excursion in cap carbonates are representative of Late Ediacaran glaciation, which has been identified worldwide. The REE+Y display light REE enrichment, unusually strong Tb-Tm anomaly, a weak positive Y anomaly, but no distinguished Eu and Ce anomalies, reflecting the glaciogenic nature of the BISF. The contents of Zr, Hf, Nb, Ta, Th, La, Ce and Y in BISF, dropstones, halite and cap carbonates are similar to those of the Neoproterozoic glaciogenic BIFs. Also, the Ni/Fe, P/Fe ratios and Fe/Ti – Al/Al + Fe + Mn + Ca + Na + K diagram suggest an exhalative hydrothermal Ediacaran-type BISF. The absence of brecciated magnetite in the ore association and the low contents of copper (9–493 ppm) and gold (<5–8 ppb) are not in favor of the IOCG – Kiruna-type iron oxide ores. The co-paragenesis of hematite with several alteration minerals, in particular actinolite, tourmaline and anhydrite, indicates that the exhalative hydrothermal fluids were generated by the interaction of seawater with the felsic rocks and sediments at about 200–500 °C. The interaction of seawater with felsic magma and sediments led to the formation of Mg-rich alteration minerals, leaching Si, Fe, Mn and other elements and forming the potential ore fluids. It is highlighted that the A-type alkaline submarine felsic volcanism could be considered as an exploration target for BISF.  相似文献   
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