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1.
杨顺良  骆惠仲 《台湾海峡》1996,15(4):324-330,T001
1990-1991年,我所对东山岛海域进行海底地形,底质调查,水文泥沙测验时发现:1)沿东山岛-古雷半岛的NNE,NE向断裂在海域呈出为落差可达20m左右“V”字型深槽。2)在东山岛东部10m等深线以东海域发育众多的水沙丘群,水深15m左右有一地形坡折线,水深20-25m海底为水下一级阶地。  相似文献   

2.
利用渤海中部海域泥温实测资料,计算出该海域海底热扩散率及恒温层深度。结果表明,8#平台处的热扩散率为0.001~0.005cm2s-1,A(B)平台处为0.002~0.010cm2s-1。恒温层深度8#平台处为8m,A(B)平台处10m,也有差异。与陆地比较,海底恒温层深度较浅,且水深越深恒温层深度越浅。  相似文献   

3.
本文根据两次在水雷营、牛鼻嘴、船坞进行3昼夜的潮汐和海流观测,及在水雷营岸北进行了1a的波浪监测和对威海湾南部近岸水域水深、地质调查资料的分析研究,结果如下:1.威海湾内外的潮汐类型属不规则半日潮,潮差平均为1.35m,潮流流速偏小,最大流速在牛鼻嘴附近海域为37cm/s(流向94°),水雷营附近海域为18cm/s(流向78°),船坞附近海域为10cm/s(流向210°)。2.牛鼻嘴、水雷营和杨家湾3处附近海域50a一遇H1/10波高分别为4.6m,4.3m和3.9m,对应的周期均为T=8.6s。3.威海湾南部海底地形虽然坡度较陡,但变化趋势较平稳,近岸水域具有岩石浅滩,并有明暗礁石分布。基岩高度起伏比较大,最大相差30m左右。4.没有外部固定输沙源,局部海岸侵蚀后退系古老片麻岩,经风化侵蚀下来的物质其量甚微,对未来海港及航道不会构成大的威胁。  相似文献   

4.
胶州湾是黄海伸入内陆的一个半封闭型海湾,位于山东半岛的南岸,分内、外两湾,总面积为388.12km。湾内平均水深为7m,湾口及湾的中部为深水区,湾顶部为浅水区。湾口朝向东南,有一条宽约3km,水深30~40m的深水槽通往外海。湾内水深域阔,风浪不大,不冻不淤,是少有的天然优良港湾[2]。胶州湾是青岛的天然宝库,青岛市经济发展与之息息相关,从某种意义上讲,没有胶州湾就不会有今天的青岛。1胶州湾及周边地质概况1.1区域地质地貌特征胶州湾在地质构造上处于胶莱盆地和胶南隆起的过渡区。自太古代以来,长期处…  相似文献   

5.
蔡明理 《海洋科学》1994,18(1):26-28
中国近海陆架地貌研究工作自50年代进行全国性海域普查以来,积累了丰富的有关黄、东海海底地质、地貌、沉积资料。在这些调查资料的基础上本文拟对黄、东海海底地貌类型、特征及其控制因素作一简单分析。1黄、东海海底主要地貌类型及其特征该区海底地貌以宽阔的大陆架为其特点。黄海呈反S状,平均深度44m。东海则呈扇形,平均水深370m,其西部为陆架,大约在水深140m左右,向东过渡为孤带状的大陆坡,主体地形为冲绳海槽,向东越过琉球群岛岛架,过渡到琉球海沟。黄、东海海底地貌类型比较齐全(图1),现分为黄海北部区、…  相似文献   

6.
东山岛以东近岸海域水下沙丘及其环境   总被引:1,自引:0,他引:1  
1990~1991年,我所对东山岛海域进行海底地形、底质调查、水文泥沙测验时发现:1)沿东山岛一古雷半岛的NNE、NE向断裂在海域呈现为落差可达20m左右“V”字型深糟;2)在东山岛东部10m等深线以东海域发育众多的水沙丘群,水深15m左右有一地形坡折线,水深20~25m海底为水下一级阶地。据底质粒度、石英电镜扫描、重矿物、地球化学指标等分析表明,水下沙丘群分布区的沉积为准残留沉积,水下一级阶地及水下沙丘为早期滨岸的准残留地貌作,又受到后期现代水动力的改造。  相似文献   

7.
若干年前,在离夏威夷群岛东南35km的太平洋海底(北纬19°,西经155°),发现了洛依希火山。它的顶部高出周围海底达3500m,离海面980m。这是夏威夷海岭所有火山中最年轻的。它位于冒纳罗亚活火山的水下斜坡上,后者的现代活动性已连续10多年了。还...  相似文献   

8.
南海海底地形以复杂著称,适合布放沉底自容式观测仪器的海区不多。通过对南海海底地形、水深、通航条件及作业时间的科学合理分析,为南海海域海底日变站布防选址提供了有效方法并取得良好的实际效果,确保了南海水下地磁日变观测的安全性。  相似文献   

9.
邵关  穆敬 《海洋测绘》2014,(1):47-49
南海海底地形以复杂著称,适合布放沉底自容式观测仪器的海区不多.通过对南海海底地形、水深、通航条件及作业时间的科学合理分析,为南海海域海底日变站布防选址提供了有效方法并取得良好的实际效果,确保了南海水下地磁日变观测的安全性.  相似文献   

10.
辽冀省间海域勘界区海底地貌特征及其划界意义   总被引:1,自引:0,他引:1  
辽冀海域勘界调查区海岸与海底地貌调查研究结果表明,调查区海岸与海底地貌均大致以红石嘴附近向海一线为界,分为东,西两大部分,西部是受大石河入海泥沙影响的以堆积作用为主的地貌发育区,潮间带以沙滩为主,水下岸坡上大石河三角洲和水下阶地发育,陆架平原由早期大石河水下三角洲堆积体为骨架构成;东部红石嘴至环海寺地嘴之间是以岬角侵蚀物质供给为主的地貌发育区,潮间带以海蚀平台和砂砾滩为主,水下岸坡上暗礁成片分布,没有水下阶地发育,由于泥沙来源有限,海底动力地貌过程以侵蚀作用为主,芷锚湾海区是以自娘娘庙至芷锚湾一带沿岸小河入海泥沙供给的,以近岸堆积,水下岸坡侵蚀为特征的地貌发育区。  相似文献   

11.
鳚亚目 4 科 33 属 95 种,鰕虎鱼亚目 5 科 98 属 259 种,刺尾鱼亚目 5 科 11 属 65 种,鲈形目 19亚目 104 科 535 属 1799 种。  相似文献   

12.
Soil-sized particulates have been collected on board ship by a mesh technique from the lower troposphere of the North, Equatorial and South Atlantic Ocean, northern and southern Indian Ocean, South and East China Sea and various coastal localities.Spectrographic analysis reveals that, on average, the particulates have concentrations of Mn, Ni, Co, Ga, Cr, V, Ba, and Sr which are of the same order of magnitude as those in average crustal material. In contrast, the average concentrations of Pb, Sn, and Zn are one order of magnitude higher than those in average crustal material.Within this “world-wide” average there are significant geographical variations in the distributions of Pb, Sn, and Zn which may be related to anthropogenic sources.On the basis of trace-element distributions lower tropospheric soil-sized marine particulates have been divided into four genetic components; local, zonal, inter-zonal, and global. The proportions of these components vary geographically, and each component may have both a natural and an anthropogenic fraction.  相似文献   

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16.
Tautog, Tautoga onitis, is an abundant species of fish in estuaries of the northeastern United States. Planktonic tautog larvae are abundant in summer in these estuaries, but there is little information on rates of growth of tautog larvae feeding on natural assemblages of food in the plankton. We examined abundance and growth of larval tautog and environmental factors during weekly sampling at three sites along a nearshore‐to‐offshore transect in Buzzards Bay, Massachusetts, USA during summer 1994. This is the first study of a robust sample size (336 larvae) to estimate growth rates of field‐caught planktonic tautog larvae feeding on natural diets, using the otolith daily‐growth‐increment method. The study was over the entire summer period when tautog larvae were in the plankton. The sampling sites contrasted in several environmental variables including temperature, dissolved oxygen (DO), and chlorophyll a concentration. There was a temporal progression in the abundance of tautog larvae over the summer, in relation to location and temperature. Tautog larvae were first present nearshore, with a pronounced peak in abundance occurring at the nearshore sites during the last 2 weeks in June. Larvae were absent at this time further offshore. From late June through August, larval abundance progressively decreased nearshore, but increased offshore although never approaching the abundance levels observed at the nearshore sites. The distribution and abundance of tautog larvae appeared to be related to a nearshore‐to‐offshore seasonal warming trend and a nearshore decrease in DO. Otoliths from 336 larvae ranging from 2.3 to 7.7 mm standard length had otolith increment counts ranging from 0 to 19 increments. Growth of larval tautog was estimated at 0.23 mm·day?1, and length of larvae prior to first increment formation was estimated at 2.8 mm indicating that first increment formation occurs 3–4 days after hatching at 2.2 mm. Despite spatial and temporal differences in environmental factors, there were no significant differences in growth rates at any of three given sites over time, or between sites. Because larval presence only occurred at a narrow range of temperature (17–23.5 °C) and DO (6.5–9.3 mg·l?1), in situ differences in growth did not appear to be because of differences in larval distribution and abundance patterns relative to these parameters.  相似文献   

17.
In June 1981, dissolved Zn, Cd, Cu, Ni, Co, Fe, and Mn were determined from two detailed profiles in anoxic Baltic waters (with extra data for Fe and Mn from August 1979). Dramatic changes across the O2H2S interface occur in the abundances of Cu, Co, Fe, and Mn (by factors of ?100). The concentrations of Zn, Cd, and Ni at the redox front decrease by factors between 3 to 5.Equilibrium calculations are presented for varying concentrations of hydrogen sulfide and compared with the field data. The study strongly supports the assumption that the solubility of Zn, Cd, Cu, and Ni is greatly enhanced and controlled by the formation of bisulfide and(or) polysulfide complexes. Differences between predicted and measured concentrations of these elements are mainly evident at lower ΣH2S concentrations.Cobalt proved to be very mobile in anoxic regions, and the results indicate that the concentrations are limited by CoS precipitation. The iron (Fe2+) and manganese (Mn2+) distribution in sulfide-containing waters is controlled by total flux from sediment-water interfaces rather than by equilibrium concentrations of their solid phases (FeS and MnCO3). The concentrations of these metals are therefore expected to increase with prolonged stagnation periods in the basin.  相似文献   

18.
Concentrations of dissolved nutrients (NO3, PO4, Si), germanium species, arsenic species, tin, barium, dimethylsulfide and related parameters were measured along the salinity gradient in Charlotte Harbor. Phosphate enrichment from the phosphate industry on the Peace River promotes a productive diatom bloom near the river mouth where NO3 and Si are completely consumed. Inorganic germanium is completely depleted in this bloom by uptake into biogenic opal. The GeSi ratio taken up by diatoms is about 0·7 × 10?6, the same as that provided by the river flux, confirming that siliceous organisms incorporate germanium as an accidental trace replacement for silica. Monomethylgermanium and dimethylgermanium concentrations are undetectable in the Peace River, and increase linearly with increasing salinity to the seawater end of the bay, suggesting that these organogermanium species behave conservatively in estuaries, and are neither produced nor consumed during estuarine biogenic opal formation or dissolution. Inorganic arsenic displays slight removal in the bloom. Monomethylarsenic is produced both in the bloom and in mid-estuary, while dimethylarsenic is conservative in the bloom but produced in mid-estuary. The total production of methylarsenicals within the bay approximately balances the removal of inorganic arsenic, suggesting that most biological arsenic uptake in the estuary is biomethylated and released to the water column. Dimethylsulfide increases with increasing salinity in the estuary and shows evidence of removal, probably both by degassing and by microbial consumption. An input of DMS is observed in the central estuary. The behavior of total dissolvable tin shows no biological activity in the bloom or in mid-estuary, but does display a low-salinity input signal that parallels dissolved organic material, perhaps suggesting an association between tin and DOM. Barium displays dramatic input behavior at mid-salinities, probably due to slow release from clays deposited in the harbor after catastrophic phosphate slime spills into the Peace River.  相似文献   

19.
Results of trace-metal analyses of water samples obtained during a cruise with the Soviet R.V. “Akademik Kurchatov” in the Indian Ocean are presented. The determinations were performed on board with atomic absorption spectrophotometry after a two-stage dithiocarbamate—Freon extraction procedure. Trace-metal concentrations found are in the same range as those found recently for similar open-ocean areas by other workers. The values for lead and zinc are probably high due to contamination. Vertical profiles indicate biogenic processes as controlling factors for the increase of cadmium, copper and nickel concentrations with depth. Iron shows an irregular depth distribution as a result of large random variations in concentration.  相似文献   

20.
Exploration for oil at Northstar has been long and costly. Northstar leases were first acquired in 1979 at a joint state and federal sale by Shell Oil, Amerada Hess, and Texas Eastern. The Northstar Unit is 6 mi offshore and about 4 mi northeast of the Point McIntyre Field. Oil was first discovered in Shell's Seal Island 1 in 1983. Five additional appraisal wells were drilled (1983-1986) from two man-made gravel islands in 40 ft of water. Early engineering estimates put the cost of development at $ 1.6 billion. In February 1995, BP Exploration (Alaska) acquired a 98 % interest in the Northstar Unit from Amerada Hess and Shell Oil. When developed by BP, Northstar will be the first oil produced from federal leases in Alaska. To date, the oil industry has invested in excess of $ 140 million in exploration and appraisal operations. An additional $ 90 million was spent on lease bonus bids. The giant Prudhoe Bay and Kuparuk Fields lie along the Barrow Arch. This arch is bounded to the north by a rift margin that deepens into the present-day offshore region. Northstar is located among a series of down-stepping faults off this northern rift margin of the Prudhoe Kuparuk high. The structure is a gently south-dipping northwest-trending faulted anticline. The crest of the structure is located near 10,850 ft subsea. The primary reservoir is the Ivishak Formation (325 ft thick) of the Sadlerochit Group. This is the same primary reservoir at Prudhoe Bay, approximately 12 mi to the south. At Northstar the Ivishak is a high-energy, coarse-grained conglomeratic facies of the Ivishak Formation. The primary lithology is a pebbly chert to quartz conglomerate with occasional sandstone. This very high net to gross reservoir appears to contain no regionally continuous permeability barriers. Cementation has reduced primary porosity to less than 15 %. Accurate porosity estimates are difficult to make due to the coarse-grained nature of the lithology and the presence of kaolinite and microporous chert. Permeability is highly variable, but averages 10 to 100 mDarcies. Oil is a very light and volatile 42 API crude with approximately 2,100 ft3 of gas per stock tank barrel of oil. This oil is very different from the heavier oils (26) found to the south in Prudhoe Bay. Estimated recoverable oil reserves range from 100 to 160 million barrels. A free-standing drilling rig is required at Northstar because the reserves are beyond extended-reach drilling techniques from shore-based facilities. The current development plan is to expand the existing Seal Island to about 5 acres. This is significantly less than Endicott's 40-acre island. The proposed drilling and produc tion island will be accessed by summer barges and winter ice roads. Oil, gas, and water will be processed at a stand-alone facility and then sent to shore via a subsurface pipeline. Northstar will have the first Arctic subsea pipeline in Alaska to transport oil to shore facilities (TAPS). Preliminary tests in Spring 1996 were very successful in demonstrating the technology to successfully bury a subsea pipeline safely in the Arctic.  相似文献   

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