首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 125 毫秒
1.
The Solomon arc lacks subduction-associated volcanism in its eastern part. This anomalous absence arose from the collision of the submarine Ontong Java Plateau with the Solomon arc about 8 m.y. ago and a consequent flip in subduction. Collision was most forceful over the eastern half, so that the new, north-plunging slab of Indo-Australian plate remained in collisional contact with the thick oceanic crust (>40 km) and lithosphere of the Ontong Java Plateau along a face of cooled depleted refractory mantle; there is no intervening asthenospheric wedge, and therefore no magma production.  相似文献   

2.
Quaternary sediments in the Woodlark Basin and New Georgia Sound, adjacent to the Solomon Islands volcanic arc, are hemipelagic. They consist of mixtures of clay minerals, calcareous plankton (foraminifera, coccoliths, and pteropods), and sand- and silt-sized volcanic debris. Variations in sediment composition are related primarily to distance from land (the source of volcanic components), water depth (because of the Aragonite and Calcite Compensation Depths), and bathymetric isolation. Much of the sedimentary debris is delivered to the basin by turbidity currents and other mass movements; little material is supplied by ash fall. Sedimentation rates appear to exceed 3 cm/1,000 years in New Georgia Sound, and range from 2 to 4.5 cm/1,000 years in the Woodlark Basin.  相似文献   

3.
A south-dipping Subduction system which underlies the Trobriand Trough and 149° Embayment, on the southern margin of the Solomon Sea, is active or was recently active. Oceanic basement is overlain by 2.5 s, two-way travel time (TWTT), of sediment that shows at least two stages of deformation: early thrusts (inner wall) and normal faults (outer wall), and later normal faults that have elevated the outer trench margin. Thrust anticlines and slope basins are developed on the inner wall. The floor of the Solomon Sea Basin arches upward between the Trobriand Trough and the New Britain Trench to form isolated peaks and ridges in the east (152° Peaks) and an east-west Central Ridge in the west. Structures in the subduction system, and in the Solomon Sea Basin, plunge westward towards the point of collision with the New Britain Trench.  相似文献   

4.
海岛生态旅游开发模式的研究有助于成熟海岛目的地开发新产品增加新收入,也有助于新进入者获得市场先发优势,对无居民海岛旅游开发具有启发意义。文章通过对国内外海岛生态旅游理论和实践研究及实地走访,提出海岛生态旅游的五大特征;依照开发活动对海岛生态系统干扰程度由低到高,将其开发模式依次分为严格的、中等的和不严格的模式;对山东长岛进行案例实证研究,对比不同开发模式的优劣势,建议山东长岛采用严格的生态旅游开发模式,实施以海洋野生动物为核心的生态旅游带动海岛自然旅游的差异化战略,获得海内外市场,并促进当地经济、社会和生态的可持续发展。  相似文献   

5.
This study assessed whether trace elements present at Deception Island, an active submarine volcano in the Antarctic Peninsula, show enhanced biological availability to the local marine community. Using a weak acid extraction method to dissolve organic material and leach associated but not constitutive trace elements of sediments, fifteen elements were measured from seafloor sediment, seawater particulates, and tissues of benthic (bivalves, brittlestars, sea urchins) and pelagic (demersal and pelagic fishes, krill) organisms collected in the flooded caldera. The highest element concentrations were associated with seafloor sediment, the lowest with seawater particulates and organism tissues. In the case of Ag and Se, concentrations were highest in organism tissue, indicating contamination through the food chain and biomagnification of those elements. The elements Al, Fe, Mn, Sr, Ti, and to a lesser extent Zn, were the most concentrated of the trace elements for all sample types. This indicates that the whole ecosystem of Deception Island is contaminated with trace elements from local geothermal activity, which is also reflected in the pattern of element contamination in organisms. Accordingly, element concentrations were higher in organisms collected at Deception Island compared to those from the neighboring non-active volcanic King George Island, suggesting that volcanic activity enhances bioavailability of trace elements to marine organisms. Trace element concentrations were highest in digestive tissue of organisms, suggesting that elements at Deception Island are incorporated into the marine food web mainly through a dietary route.  相似文献   

6.
Bowers Swell is a newly discovered bathymetric feature which is up to 90 m high, between 12 and 20 km wide, and which extends arcuately about 400 km along the northern and eastern sides of Bowers Ridge. The swell was first revealed on GLORIA sonographs and subsequently mapped on seismic reflection and 3.5 kHz bathymetric profiles. These geophysical data show that the swell caps an arcuate anticlinal ridge, which is composed of deformed strata in an ancient trench on the northern and eastern sides of Bowers Ridge. The trench fill beneath the swell is actively deforming, as shown by faulting of the sea floor and by thinning of the strata across the crest of the swell. Thinning and faulting of the trench strata preclude an origin for the swell by simple sediment draping over an older basement high. We considered several models for the origin of Bowers Swell, including folding and uplift of the underlying trench sediment during the interaction between the Pacific plate beneath the Aleutian Ridge and a remnant oceanic slab beneath Bowers Ridge. However, such plate motions should generate extensive seismicity beneath Bowers Ridge, which is aseismic, and refraction data do not show any remnant slab beneath Bowers Ridge. Another origin considered for Bowers Swell invokes sediment deformation resulting from differential loading and diapirism in the trench fill. However, diapirism is not evident on seismic reflection profiles across the swell. We favour a model in which sediment deformation and swell formation resulted from a few tens of kilometers of low seismicity motion by intraplate crustal blocks beneath the Aleutian Basin. This motion may result from the translation of blocks in western Alaska to the south-west, forcing the movement of the Bering Sea margin west of Alaska into the abyssal Aleutian Basin.  相似文献   

7.
Future fish demand-supply scenarios project that investment in aquaculture will be needed to ensure fish for food security in Solomon Islands. In 2010 a study of two peri-urban areas of Solomon Islands analysed the demand and potential for inland aquaculture, and the role of the introduced Mozambique tilapia (Oreochromis mossambicus) in household livelihoods and existing value chains. Of 178 households interviewed, marine reef fish were the preferred fish for consumption, although tinned fish was also common. At the study sites, Mozambique tilapia was accessible and contributed to food security, particularly for inland households. Sixty five percent of the people actively fished for tilapia at least monthly; 13% of these fished on almost a daily basis. Fish were consumed by men, women and children and sold by both men and women in local village markets. Mozambique tilapia is considered to perform poorly in aquaculture. While other species like Nile tilapia or milkfish (Chanos chanos) are being considered for aquaculture by the Solomon Islands Government, Mozambique tilapia is currently the only cost-effective and widely available alternative for farming fish for household food security. This study lends weight to the premise that peri-urban households that are cash poor are likely to benefit nutritionally from easier access to tilapia or other freshwater fish.  相似文献   

8.
我国海岛管理信息化建设问题与对策研究   总被引:1,自引:0,他引:1       下载免费PDF全文
海岛管理信息化建设是《中华人民共和国海岛保护法》赋予海洋行政主管部门的主要职责之一。文章分析研究我国海岛管理信息化建设的背景和现状,指出面临的一系列问题,从总体规划、数据应用、完善机制、统筹管理、加强配套、保障安全等方面提出相应对策,为我国海岛管理信息化建设提供参考。  相似文献   

9.
周庆冲 《海洋测绘》2004,24(1):27-30
利用湛江市硇洲岛和大黄江跨海水准测量项目所采集的实测数据进行有效的计算和较深入的分析,研究了GPS及水准联测实施跨海水准测量确定海岛验潮站基准面的方法,得出了有推广应用价值的结论。  相似文献   

10.
《Ocean & Coastal Management》2006,49(7-8):421-441
This paper evaluates governance arrangements in Solomon Islands in terms of their ability to achieve the integrated management of coastal environments. The paper uses a modified version of the framework proposed by Ehler CN [Indicators in measure governance performance in integrated coastal management. Ocean & Coastal Management 2003; 46: 335–345] for evaluating governance performance. The results point to a systemic failure of coastal governance in Solomon Islands. The paper identifies the strategic issues for governance reform if the management of coastal environments and resources in Solomon Islands is to be improved.  相似文献   

11.
粤东南澳岛立足海岛特色旅游资源优势,着力开辟旅游新线路,创办游乐新项目,做活了生态旅游文章,成为海内外游客休闲度假的好去处,观光览胜的热点.2000年,登上这个海岛县旅游度假的游客达50多万人次,全县旅游综合收入达1.6亿元,分别比1999年增长25%和11%.  相似文献   

12.
海岛地区地质环境条件相对较复杂,地形起伏较大,地貌类型多样,地热地质条件特殊,选用合适的地热资源勘查定井的方法,对地热资源的勘查开发具有重要意义。以典型海岛−青岛市小管岛的地热资源勘查工作为例,综合分析小管岛地热地质条件,对比分析地热资源勘查物探方法的优缺点,有针对性地采用音频大地电磁测深(AMT)和高精度电磁频谱法(MES)相结合的勘查定井方法进行地热资源勘查。综合2种物探方法解释成果,获取研究区热储概念模型,确定地热井位置,成功施工1500 m地热井1眼,出水量121.2 m3/d,孔底温度39.2 ℃。根据小管岛地热资源勘查实例表明,采用AMT法和MES法在海岛地区进行地热资源勘查是可行的、有效的。  相似文献   

13.
文章根据2017年涠洲岛最新珊瑚本底调查资料,对比分析近10年来,涠洲岛珊瑚种类数量、分布状态以及优势物种变化状况。结果表明,涠洲岛珊瑚以造礁珊瑚为主体,高达10科23属41种,其次为分布有较多的柳珊瑚,为4科12属14种,此外也分布有少量的软珊瑚、群体海葵;珊瑚主要分布于近海海岸一带,以0. 5~6 m的珊瑚礁坪生长带为主,具有明显的分带特点;对比2008年调查数据,本次调查发现涠洲岛海域珊瑚优势物种发生了变化,由角蜂巢珊瑚属变为滨珊瑚属,蔷薇珊瑚属不再是优势属,反而新增了蜂巢珊瑚属和牡丹珊瑚属,此外珊瑚覆盖度较2008年出现了下降趋势,表明了涠洲岛珊瑚生存状况受到了人为活动等因素的影响。  相似文献   

14.
在完成海岛像控测量、野外调绘、空三加密、内业测图等航空摄影测量技术流程,测绘比例尺1:10000海岛地形图,制作相应的数字高程模型、正射影像图等产品的基础上,总结了航测技术应用于海岸、海岛地形测绘的技术方法、作业流程,并将航测成果与常规海岸地形测量成果进行比对,得出了航测成果精度能够满足<海道测量规范>要求,航测技术可...  相似文献   

15.
车牛山岛铠平鲉繁殖群体生物学研究   总被引:5,自引:0,他引:5  
利用2009年12月在海州湾车牛山岛调查采集的60尾标本,初步研究该海域铠平鲉群体的繁殖群体生物学特征。铠平鲉繁殖群体体长范围64~119mm,体质量范围6.4~60.2g,年龄组成Ⅱ~Ⅷ龄,性比1.5∶1,以Ⅳ龄和Ⅴ龄组占优势,成熟个体最低年龄为Ⅱ龄,最高年龄为Ⅷ龄。绝对怀卵量变动于327~7 706粒之间,平均3 387粒;相对怀卵量变动于29~204粒/g,均值126粒/g。绝对怀卵量与纯质量的关系为E=126 W-326.27,与体长的关系为E=6×10-7 L4.352。以矢耳石切片为材料鉴定年龄并用Von Bertallanffy方程描述其生长,结果显示雌雄生长差异显著,生长方程分别为雌性Lt=135.5×(1-e-0.158×(t+3.578)),雄性Lt=136.9×(1-e-0.148×(t+3.289))。根据生态参数判断,铠平鲉属于偏k-选择型鱼类。  相似文献   

16.
《Marine Geology》2004,203(1-2):119-140
The results of a combined geophysical and geochemical research programme on Deception Island, an active volcano at 62°43′S, 60°57′W in Bransfield Strait (Antarctica), are presented. Ultrahigh-resolution acoustic data obtained with a TOPAS (TOpographic PArameter Sonar) system and multibeam bathymetry (Simrad EM1000) allow a detailed analysis of submarine vents in Port Foster, the submerged caldera of Deception Island. The data show three different types of seafloor structures: low-relief mounds, high-relief mounds (‘wasp nest’-like) and spire-like structures. We interpret these structures as products of sediment volcanism and seeps caused by heating and boiling of pore fluids in gas-charged sediments, and related to recent short-lived volcanic events, possibly those that occurred in 1967, 1969 and 1970. In addition, subsurface vertical disturbed zones, formed by increased amplitude and phase-inverse reflectors beneath the mounds, suggest the presence of fluidised and brecciated sediments within hydrofracture systems. A key finding of this study is that there appears to be a close relationship between the submarine mounds detected by our ultrahigh-resolution seismic study, geochemical haloes, fault-pathways and present-day thermal anomalies in surface waters. We suggest that seafloor hydrofracture systems and subsurface pipes can be re-used as fluid migration pathways, resulting in hydrothermal seeps and vents on the seafloor, possibly up to decades after coeval volcanic eruptions.  相似文献   

17.
文章主要应用层次分析法和模糊综合评价法对温州市海岛保护规划进行分类研究。将温州市海岛保护分为优化开发类岛群、重点开发类岛群、一般保护类岛群和特殊保护类岛群4种类型,根据分类结果可以统筹海岛保护、开发、建设和管理,以保护海岛及其周边海域生态系统,合理开发利用海岛自然资源,实施海岛分类管理,突出海岛分区特色,安排海岛保护重点工程布局,建立健全海岛规范化管理制度,切实加强规划在宏观调控和监督管理方面的重要作用。  相似文献   

18.
Parties to the convention on international trade in endangered species of wild fauna and flora (CITES) can export specimens if the exporting party issues a non-detriment finding (NDF), stating that removals will not harm wild populations. NDFs are supposed to be based on science. This article discusses the issuance, and acceptance, of non-detriment findings despite concerns expressed by experts and a lack of scientific data, using a controversial trade of dolphins as a case study. In early 2003, at least 94 Indo-Pacific bottlenose dolphins (Tursiops aduncus) were captured in the coastal waters of Solomon Islands. Bottlenose dolphins are listed on CITES Appendix II and as such require an NDF for their export. The IUCN Cetacean Specialist Group advised against this proposed export, stating that it knew of no published population assessments or other research upon which a valid NDF could be based. Despite this, in July 2003, 28 dolphins were exported to Mexico. A second controversial export occurred on 18 October 2007, when 28 dolphins were exported from Solomon Islands to the United Arab Emirates, an export regarding which IUCN experts again expressed concerns. Two additional exports, of 18 dolphins total, went to the Philippines in 2008.  相似文献   

19.
广东海岛资源特征与开发对策   总被引:1,自引:0,他引:1  
利逸  周厚诚 《海岸工程》2010,29(1):75-82
从空间资源、生态资源、旅游资源、海洋能资源、战略资源等方面阐述广东省海岛资源特征,分析了广东省海岛的保护与利用现状和海岛资源开发的制约因素,总结海岛资源的组合类型,提出海岛开发对策。  相似文献   

20.
国外海岛旅游开发经验对我国海岛旅游开发的启示   总被引:10,自引:2,他引:10       下载免费PDF全文
海岛旅游有着休闲与放松,浪漫与时尚,远离城市喧嚣等特点,因此近年来备受旅游者的喜爱,逐渐成为旅游业的热点.现在,国外很多海岛的旅游业达到了高度发展的状态,而中国海岛旅游正处在积极地进行旅游开发建设中,因此,需要借鉴世界一些已经成熟发展的海岛旅游经验来促进我国海岛游的健康快速发展.文章首先论述我国海岛旅游发展存在的问题及不足;其次,借鉴世界著名海岛旅游的成功开发经验;最后,提出了一些发展我国海岛旅游业的建议.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号