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The purpose of this article is to draw attention to a change in the trend of Soviet naval developments. This change stems from a combination of: (1) a sharp increase in the allocation of resources to naval shipbuilding; (2) a marked rise in the navy's political influence; and (3) a new approach to the role of seapower in Soviet policy. Professor MccGwire, Senior Fellow at the Brookings Institution, USA, believes that both the nature and the significance of the change are being obscured by the fact that for the past decade naval leaders in the West have been talking of ‘a Soviet naval build-up’, and continue to use the same language to describe the very different present situation. There is no general awareness, even within naval circles, that we are now facing a significant change in established trends. This article draws on a longer and more general article.1  相似文献   

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西太平洋暖池变异及其对西太平洋次表层海温场的影响   总被引:9,自引:0,他引:9  
应用热带太平洋上层XBT温度资料,分析研究了西太平洋暖池区(0°~16°N,125°~145°E)上层海洋的变化特征以及与西太平洋次表层海温场之间的关系.研究表明,西太平洋暖池区的垂向温度存在显著的年际变化,尤其在次表层(120~200m)的变化最为明显.西太平洋暖池区的次表层冷暖信号明显早于西太平洋次表层的海温异常.分析发现,西太平洋暖池区的海温异常是导致整个西太平洋次表层海温场变异的关键区,当西太平洋暖池区的次表层冷暖信号加强时,3~4个月后西太平洋海温场出现大范围的冷暖异常.  相似文献   

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Navy Fan is a Late Pleistocene sand-rich fan prograding into an irregularly shaped basin in the southern California Borderland. The middle fan, characterized by one active and two abandoned “distributary” channels and associated lobe deposits, at present onlaps part of the basin slope directly opposite from the upper-fan valley, thus dividing the lower-fan/basin-plain regions into two separate parts of different depths. Fine-scale mesotopographic relief on the fan surface and correlation of individual turbidite beds through nearly 40 cores on the middle and lower fan provide data for evaluating the Late Pleistocene and Holocene depositional processes. Margin setting represents fan and/or source area  相似文献   

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Navy Fan is a Late Pleistocene sand-rich fan prograding into an irregularly shaped basin in the southern California Borderland. The middle fan, characterized by one active and two abandoned “distributary” channels and associated lobe deposits, at present onlaps part of the basin slope directly opposite from the upper-fan valley, thus dividing the lower-fan/basin-plain regions into two separate parts of different depths. Fine-scale mesotopographic relief on the fan surface and correlation of individual turbidite beds through nearly 40 cores on the middle and lower fan provide data for evaluating the Late Pleistocene and Holocene depositional processes.  相似文献   

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《Ocean & Coastal Management》2006,49(9-10):610-626
This paper focuses on pilot activities being carried out under the Integrated Coastal Watershed Management component of the Pacific International Waters Project (IWP). The paper discusses a two-pronged approach being taken to address the root causes of identified threats to the international waters of 14 Pacific Island countries. National and local level activities are focusing on coastal fisheries, waste management and freshwater protection. The integrated strategic approach of participatory planning processes, social analysis, resource economics and communications in identification of environment problems, their causes and potential solutions for supporting behavioural change in relation to resource use and management is discussed. Some examples of country activities to date are provided. Although it is too early to assess a full range of lessons and project impacts, a number of key issues continue to provide challenges for the implementation of a large regional programme such as the IWP. They include: multi-sectoral stakeholder engagement; the establishment of partnerships needed to support integrated coastal management; and national capacity to implement community-based resource management projects.  相似文献   

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Sourcing seafood for the three major markets: The EU,Japan and the USA   总被引:1,自引:0,他引:1  
This paper describes the marine fish and invertebrate consumption in three of the world’s major seafood markets (the EU, Japan and the USA) using a series of global maps indicating the likely origin of the seafood consumed by each market. These maps display a high level of dependence by these markets on foreign sources as the serial depletion of local fisheries resources forced the fleets in search for new seafood supplies well beyond their domestic waters. The acquisition of foreign (and high seas) seafood by these markets is conducted through two channels: by dispatching distant water fishing fleets that directly exploit foreign stocks; and by importing catch landed elsewhere by local fleets. The results also demonstrate that each of the three major markets occupies a zone of influence within which it is dominant.  相似文献   

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Variability of the North Pacific Current and its bifurcation   总被引:2,自引:0,他引:2  
The North Pacific Current (NPC) bifurcates approaching the west coast of North America into a subpolar branch that forms the Alaska Current, and a subtropical branch that includes the California Current. The variability of this current system is discussed using numerical results from a wind-driven, reduced-gravity model. Indices of the strength of the subpolar and subtropical components of the NPC are examined based on output from multi-decadal simulations with the numerical model. This shows periods of both correlated and anti-correlated variability of the subpolar and subtropical gyres. A decomposition of the gyre transport time series indicates that the dominant mode of variability is a “breathing” mode in which the subpolar and subtropical gyres co-vary in response to fluctuations in the strength of the NPC. This finding is consistent with an analysis of dynamic height data of limited duration from the array of Argo drifting floats.The variability of the NPC is also examined using sea surface height (SSH) data from satellite altimetry over the period 1993-2005. The leading mode of SSH over the northeast Pacific dominates the variability of the NPC and is shown to be associated with in-phase variations in the transport of the subtropical and subpolar gyres. A strong correlation is found between time-dependent fluctuations in SSH across the NPC and variations in the strength of the transport of the NPC in the model. This agreement provides evidence for variability of the NPC occuring in direct response to large-scale atmospheric forcing.  相似文献   

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太平洋海平面变化特征及影响因素分析   总被引:6,自引:2,他引:4  
采用经验模态分解法对太平洋沿岸验潮站的月平均海平面资料进行处理,结合T/P高度计资料、Church(2004)重构SSH资料、Ishii(2005)月均海温资料,研究太平洋海平面年际、年代际变化以及资料长度内海平面变化趋势。太平洋沿岸海平面总体呈上升趋势,平均上升速率为1.4 mm/a,趋势项分布有明显的区域性和纬度特征。ENSO对太平洋地区海平面年际变化有显著影响,海平面年际变化与Nino3指数在西(东)太平洋为负(正)相关,海平面年际变化与Nino3指数的相关性在热带太平洋最大,并随着纬度升高相关性减弱,且不同地区年际变化有滞后ENSO时间不等的最大相关。海平面年际变化与PDO指数在西(东)太平洋为负(正)相关,海平面与PDO的相关性分布有区域性和随时间演变特征。年代际变化对目前使用卫星高度计资料分析海平面长期趋势项的预测有直接影响,可能完全掩盖海平面长期变化趋势。  相似文献   

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对东太平洋海盆 430 柱沉积物的组分、古生物、结构构造以及古地磁、铀系等进行研究后, 将沉积物进行分类、命名与分层, 并确定其年代。研究表明, 本柱由下至上的沉积物分别为含沸石粘土、深海粘土、硅质粘土和钙质粘土。该柱中存在 4 个沉积间断, 其中在 325 cm附近层位有一厚约 10 cm 的多金属结核层,此界面为中中新世至晚上新世的沉积间断,它在 C C区内普遍存在, 持续时间长, 分布范围广。反映此时南极底层流十分强盛, 对东太平洋 C C 区的沉积作用和多金属结核形成与发育产生重要的影响。  相似文献   

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西太平洋副热带高压变化与赤道太平洋海温场的联系   总被引:2,自引:1,他引:2  
陈迪  陈锦年  左涛 《海洋学报》2013,35(6):21-30
通过对西太平洋副热带高压变化的多年统计分析,发现其具有明显的年际和年代际变化特征,副高面积和强度均存在3~4 a和11~14 a显著周期,副高西伸脊点存在3~5 a和准13 a显著周期。副高面积和强度变化基本一致,与赤道中东太平洋海表温度(SST)存在显著的正相关关系,西伸脊点与中东太平洋海表温度变化则存在负的相关关系。赤道太平洋不同经度的SST与副高变化存在明显的差异,赤道中太平洋SST异常与副高变化的关系最为密切,东太平洋相对偏弱,而西太平洋呈现相反的相关关系。由此可以认为,赤道中太平洋异常SST变化是影响副高变化的关键区域。根据它们之间存在的密切关系,通过回归分析,建立了它们二者之间的回归方程,对2013年春夏季副高的强度和西伸脊点位置变化进行了预测,为2013年我国汛期降水预测提供一定的参考。  相似文献   

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东太平洋以其发育大洋多金属结核而长期以来倍受地质学家关注,国内外在该区对多金属结核及相关的沉积物、沉积环境、古海洋学等进行了大量的调查研究[1~6],取得了许多重要的研究成果.在此基础上,笔者利用先进的电镜分析测试技术(包括电子衍射技术),对东太平洋克拉里昂和克利伯顿两条断裂带之间的CC区沉积物进行了系统的矿物学研究,在研究中发现了重晶石和锐钛矿矿物.本文将简要报道对这两种矿物的形貌和结构标型特征进行研究的结果,并初步探讨其成因[1].  相似文献   

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运用分形理论,通过建立不同的相空间,计算了东太平洋多金属结核中的铁、锰元素的时间序列在各相空间中的关联分维,并与其在沉积物岩心中的关联分维进行了对比.通过研究发现,多金属结核中铁、锰元素和沉积物中Fe2O3及MnO在分形演化过程中均存在分维吸引子,认为沉积物中的Fe2O3和MnO可以用3个变量来描述,它们可能代表了火山、生物和陆地的三种来源,而描述结核中的铁、锰元素却需要14个变量,反映多金属结核中铁、锰元素的来源和/或赋存非常复杂,至少有14个因素在起作用,可能暗示了结核在形成过程中存在复杂的生物化学作用,为多金属结核的生物成因提供了间接的数学证据,同时也合理解释了结核生长结构所具有的自相似韵律现象.  相似文献   

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We describe the distribution and abundance of the midwater fish community, between 200 m and 500 m, in the North Pacific. The main area of interest was the Subarctic Pacific gyres, but we include species from the Bering Sea and the Sea of Okhotsk. There were 196 species identified in each gyre, 38 of which were common to both gyres. The most abundant species belong to the family Myctophidae and the most ecologically important myctophid probably is Stenobrachius leucopsarus. This species could have a biomass of approximately 21 million tonnes (t) in the Subarctic Pacific (including the Bering Sea and Sea of Okhotsk). S. leucopsarus is a small (about 8 cm maximum length) fish that lives up to 7 years. It is prey for a variety of other fishes, birds and mammals and may migrate into the mixing layer each evening where it feeds mainly on euphausiids and copepods.The total abundance of midwater fishes appears to be large relative to total catches of other fish in the same areas. The vertical migratory behaviour of some of the residents provides a mechanism to transfer production out of the mixing layer. The movement into the surface layer by some fishes at night indicates that dynamic changes occur in the midwater community between the day and night, and the ecosystem dynamics in the surface layer are different in the day and in the night. This behaviour and the huge biomass relative to commercial species means that the dynamics of fish communities in the Subarctic Pacific are complex and need to be studied over a 24 hour period. The large biomasses may eventually attract commercial interest, thus it is important to establish international, cooperative programs now to learn more about the dynamics of these populations and the relationships with other species.  相似文献   

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