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1.
《海洋科学集刊》2016,(0)
本文以科学引文索引扩展版(science citation index expanded,SCIE)数据库和社会科学引文索引(social sciences citation index,SSCI)数据库中有关海沟研究的文献为数据源,利用Thomson Data Analyzer、Ucinet、VOSviewer和Excel分析软件,结合PathFinder算法,对检索到的数据进行数据挖掘和定量分析,通过揭示国际上关于海沟研究的主要国家或地区机构之间的合作及其发文情况,总结国际上有关海沟研究领域的发展态势,以期把握海沟研究的整体发展状况,为科研人员进一步研究提供较详尽的参考资料。 相似文献
2.
1995年3月4日,日本海洋科技中心“横须贺”号工作母船成功地将无人潜水探测机“海沟”号沉放到马里亚纳海沟最深处,并查明世界最深海沟的深度为10 911.4米。“海沟”号今后将着重调查马里亚纳海沟下的板块变形状况,为研究发生地震的原因提供第一手资料。还将调查马里亚纳海沟和伊豆小 相似文献
3.
《热带海洋学报》2017,(6)
俯冲的大洋板块在自身的重力以及上覆板块的挤压下,下潜时牵引洋底向下倾伏,从而形成了深邃的海沟。板块及其所携带的沉积物在这里俯冲到地幔深处,构成了全球物质循环的重要部分。海沟地处极端环境,海沟沉积物的沉积作用不同于陆架和浅海地区,其物源和水动力基本控制了沉积模式,但海沟沉积物的物源、沉积环境和沉积机理则更为复杂。海沟沉积物受控于各种类型的构造运动,包括由上覆板块刮削下来的深海沉积物和洋壳碎片堆积而成的沉积增生楔;由海沟重力滑塌、地震等因素引发的浊流沉积;以及由火山活动带来的火山物质等。同时,海沟沉积物也受控于海沟逐渐形成过程中和形成后的各种沉积作用,例如生物化学沉积和漏斗效应。由于海沟沉积物的沉积过程受到漏斗效应的影响,使得海沟沉积一般比深海盆地堆积速度更快,堆积厚度也更大,但在海沟的不同位置或不同海沟之间,堆积厚度也会有所不同。海沟的这些沉积机理和沉积过程的差异,影响了海沟沉积物的性质,包括沉积物粒度、矿物、生物等都有所差异。文章根据海沟以上的沉积特点,分析了不同海沟之间和同一海沟内部海沟沉积厚度以及沉积物的粒度特征、矿物组成和生物特征的差异,并总结了海沟重力滑塌、浊流沉积、火山活动、生物化学沉积、漏斗效应这五种海沟沉积机理对海沟沉积物沉积过程的影响。文章最后展望了海沟沉积物的研究热点,希望在此基础上促进海沟沉积物的进一步研究。 相似文献
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菲律宾海周边的深海沟地貌 总被引：2，自引：0，他引：2
菲律宾海是西太平洋最大的边缘海,它处在东海、南海和太平洋之间,被周围的岛弧、海岭所围绕,在每个岛弧东坡或东南坡的坡脚都存有深海沟,菲律宾海就被其周边的深海沟所环绕。学者们对这些深海沟曾有过许多报道,本文依据前人的资料和本所的部分资料对这些深海沟作以下整体的研究。1 菲律宾海周边的深海沟菲律宾海周边的深海沟和海槽呈链状环绕着菲律宾海,它们是西南缘的菲律宾海沟,西北缘的琉球海沟,东至东南缘的伊豆-小笠原海沟、北马尼亚纳海沟(硫黄海沟)和马尼亚纳海沟,南缘的雅浦海沟和帛琉海沟。此外在西缘有北吕宋海槽,在北至西北缘有… 相似文献
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太平洋深海钻探和板块构造总结Г、Ｍ、ＢπａｃｏＢ沿着日本海沟、马里亚纳海沟和两条中美海沟的横剖面进行了深海钻探。对千岛－堪察加海沟、阿留申海沟、秘鲁－智利海沟和华盛顿－俄勒冈海沟则主要采用地震方法（多道地震探测等）进行了研究。在主要的太平洋海盆中打了... 相似文献
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海沟通常拥有全球最深的区域——深渊,由于地理位置、地形地貌和气候等差异,海沟沉积物可能有不同的物质来源。因此,为进一步了解海沟深渊区的物质组成与来源,选取近陆的新不列颠海沟作为研究对象,通过分析其海底表层沉积物的地球化学特征,追踪新不列颠海沟不同水深与区域的沉积物来源。研究发现不论位于半深海、深海,乃至深渊区域,新不列颠"八字型"海沟的表层沉积物主要来自于周边岛屿的火山物质,但"八字型"海沟的西支和东支有差异,西支主要为新不列颠岛东部Rabaul火山和北部火山群及所罗门群岛的火山物质,其中在西支的最北站位新不列颠岛北部火山物质的比例最高。与西支相比,东支还受到了更多来源于TLTF(Tabar、Lihir、Tanga和Feni火山)火山链物质的影响,海沟东西支物源的差异与该地区复杂的洋流密切相关。此外,西支海沟轴部(最底端)站位更多来源于岛屿河流沉积物,受火山物质影响相对较小。 相似文献
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俯冲带是地球上最大地震的发源地。俯冲板块正断层为海水进入上地幔，引起蛇纹石化提供通道，其地震可能引发大海啸。研究其动力学机制，对推动俯冲带动力学过程研究及保护人类生命安全都具有重要意义。本文综述了西太平洋汤加海沟、马里亚纳海沟、伊豆-小笠原海沟和日本海沟俯冲板块外缘隆起带到海沟附近的正断层分布与变形特征，定量化阐明了地球动力学模拟方法揭示的西太平洋俯冲板块正断层形成过程。研究发现汤加海沟和马里亚纳海沟的正断层平均断距最大；俯冲板片有效弹性厚度变化直接影响正断层形成区域，而有效弹性厚度与板块年龄相关性较大。本文系统性回顾了西太平洋俯冲动力学研究并且提出了对未来相关研究的启示。 相似文献
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海沟是全球大洋体系的重要组成部分。研究这一极端环境的生物地球化学循环过程有助于我们进一步理解海洋的物质循环。前期研究发现,海沟表层水体的初级生产力(NPP)对海沟沉积物埋藏的有机碳性质具有重要影响,但是,颗粒有机碳(POC)在沉降过程中被微生物呼吸和降解的过程尚不清楚。因此,本研究利用2018年春"太阳号"阿塔卡马海沟(Atacama Trench)国际联合航次SO261所采集的表层水样品,测试其中POC浓度、C/N、δ~(13)C、δ~(15)N等参数,并结合0.2—0.8、0.8—3.0、3.0μm三种粒径微生物群落呼吸(microbial community respiration,MCR)速率测试,探究其日变化模式及不同站位的空间变化模式,进而衡量微生物对POC的呼吸降解作用。结果表明,该海域表层水中对POC降解占主导作用的微生物类群粒径为0.8—3.0μm;24 h时间序列实验表明MCR随时间呈现"M"型曲线的双峰变化模式,且和C/N、δ~(13)C、δ~(15)N等参数变化趋势吻合,表明同一站位的呼吸速率主要与光强有关,并对代谢有机碳的元素性质产生影响;在空间上,海沟站位表层的MCR显著大于非海沟站位,并受初级生产力的影响。最后,本文计算得到表层水微生物对NPP的呼吸降解比例在0.5%—4.6%之间。 相似文献
11.
Arne Schnack-Friedrichsen Angela M. Davis Jim D. Bennell Dei G. Huws 《Marine Georesources & Geotechnology》2001,19(4):221-243
The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths. 相似文献
12.
Shigehisa Nakamura 《Marine Geodesy》2000,23(1):55-61
Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone. 相似文献
13.
The effect of different fixation and storage protocols on the flow cytometric (FCM) simultaneous analysis of bacterioplankton and phytoplankton in coastal seawater samples (Mediterranean coastal lagoons) was investigated. FCM measurements (cell number, fluorescence and scatter characteristics) were obtained through DAPI staining. Three fixatives [glutaraldehyde (GA), formaldehyde (FA) and paraformaldehyde (PFA)] and two storage (3 months duration) methods (5 °C and −196 °C) were tested. Two dominant populations were detected in studied samples: bacteria and eukaryotic picophytoplankton. Adding fixatives (2% final concentration) appears necessary to obtain FCM exhaustive counts of all the bacteria and phytoplanktonic cells. This was related to the permeation effect of fixatives which allowed a better DAPI staining of the cells. Maximum fluorescence, i.e. optimal staining of the cells was obtained with FA or PFA, and significant lower fluorescences with GA. Fixed samples stored at 5 °C induced rapid cell loss. Only storage in liquid nitrogen of samples fixed with FA or PFA, allows mid-term (≥4 months) preservation of bacteria or picophytoplankton cell numbers, and limited evolution of DAPI-induced fluorescence and scatter characteristics. 相似文献
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《海洋学报(英文版)》2014,(9):F0003-F0003
<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology, 相似文献
16.
The relationship between the flux of exotic benthic foraminiferal tests (i.e. tests which are supplied from open-sea sources alone) in a tidal inlet and that of bulk sediment was analysed, which can be expressed as two first-order linear equations. According to this relationship, in order to determine net sediment transport directions in the entrance, the test concentration in surficial sediments of the tidal basin can be compared against a ‘ critical level ’. The critical level is determined for the conditions that no net transport of bulk sediment is present within the entrance. If the observed concentration (averaged over the tidal basin) is higher than the simulated critical level, then the net sediment transport is directed to landward. This method is applied to the analysis of net sand transport at Christchurch Harbour, a tidal inlet system located in southern England. In this investigation, concentrations of exotic foraminiferal tests in the surficial sediments of the tidal basin and ebb tidal delta area were obtained from the analysis of sea-bed sediment samples. A series of probable critical levels were calculated based upon the data sets with regard to: (1) sediment discharge from the rivers; (2) magnitude of sediment discharge within the entrance during the ebb; (3) the test concentration outside the harbour; (4) the thickness of the moving layer; and (5) two parameters associated with dispersive processes. The results show that the concentration in the tidal basin sediment is higher than a number of simulated critical concentrations for representative cases. Consequently, the high level of the concentration of exotic benthic foraminiferal tests within the harbour should be explained as a result of landward net transport of sands within the entrance. 相似文献
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Coastal inundation associated with extreme sea levels is the main factor which leads to the loss of life and property whenever a severe tropical cyclonic storm hits the Indian coasts. The Andhra and Orissa coasts are most vulnerable for coastal inundation due to extreme rise in sea levels associated with tropical cyclones. Loss of life may be minimized if extreme sea levels and associated coastal flooding is predicted well in advance. Keeping this in view, location specific coastal inundation models are developed and applied for the Andhra and Orissa coasts of India. Several numerical experiments are carried out using the data of past severe cyclones that struck these regions. The simulated inland inundation distances are found to be in general agreement with the reported flooding. 相似文献
19.
Rahul Sharma 《Marine Georesources & Geotechnology》2000,18(3):237-250
Observations on seafloor features from subbottom profiling and seabed photography data show that the undisturbed and natural conditions before the benthic disturbance undergo a substantial change after operation of the disturber. The effects can be seen in the form of deep trenches and grooves, formed by the action of the sleds and the pumping of the sediment along its path, as well as sediment piles on either side of the track. Biological traces such as fecal coils, casts, tubes, burrows, and trails get obliterated in the areas of disturbance and resedimentation. The smooth, uniform nature of the seafloor observed in predisturbance phase shows microtopographic changes in and around the disturbed area as a result of sediment excavation and resettlement. Vertical mixing as well as lateral transport of sediment alter the geological, biological, physical, and chemical conditions on the seafloor, which need to be monitored over time to assess the process and the time taken for restoration of environmental conditions. 相似文献
20.
Vance P. Vicente 《Marine Ecology》1989,10(2):179-191
Abstract. Long-term changes in the distributional patterns of commercial sponges ( Spongia spp. and Hippospongia spp.) within the West Indian Region indicates that: 1) commercial sponges had a widespread distribution throughout the whole West Indian Region and were ubiquitous in very shallow water until about the first half of the present century; 2) they were fished commercially not only in the traditional northern Caribbean sites (Florida, Gulf of Mexico, Bahamas) but also in the Greater ( e. g. , Hispaniola, Jamaica) and Lesser Antilles; and 3) they became extinct throughout most of the Lesser Antilles ( e. g. , Puerto Rico, Vieques, St. Thomas) sometime during the first half of this century. Mortalities of spongiids within the Antilles were found to differ from other marine mortalities in that: 1) species disappeared from a large region; 2) species vanished from different habitats and depths; and 3) natural populations never recovered. Species richness patterns suggest that commercial sponge genera ( Spongia and Hippospongia ) evolved under slightly cooler elimatic conditions than those found at present, and that these extinctions occurred as a direct or indirect effect of positive thermal anomalies in sea surface and atmospheric temperatures between 1900–1950. The concept that species diversity is stable on a regional scale is questioned. 相似文献