A Simulation Model of a Deep Meiobenthic Compartment: A Preliminary Approach     

F. de  Bovee J. Ph.  Labat 《Marine Ecology》1993,14(2):159-173

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Benthic Front and the Yamato Basin Bottom Water in the Japan Sea     

Tomoharu?SenjyuEmail author  Yutaka?Isoda  Takafumi?Aramaki  Shigeyoshi?Otosaka  Shinzo?Fujio  Daigo?Yanagimoto  Takashi?Suzuki  Kenshi?Kuma  Kosuke?Mori 《Journal of Oceanography》2005,61(6):1047-1058

Hydrographic observations have revealed detailed structure of the Bottom Water in the Japan Sea. The Yamato Basin Bottom Water (YBBW) exhibits higher temperatures and lower dissolved oxygen concentrations than those found in the Japan Basin Bottom Water (JBBW). Both Bottom Waters meet around the boundary region between the Yamato and the Japan Basins, forming a clear benthic front. The structure of the benthic front suggests an estuary-like water exchange between both Basins, with the inflow from the Japan Basin passing under the outflow from the Yamato Basin. It is inferred from the property distributions that the JBBW flowing into the Yamato Basin is entrained by the cyclonic circulation in the basin, and modified to become the YBBW. Vertical diffusion and thermal balance in the YBBW are examined using a box model. The results show that the effect of geothermal heating has about 70% of the magnitude of the vertical thermal diffusion and both terms cancel the advection term of the cold JBBW from the Japan Basin. The box model also estimates the turnover time and vertical diffusivity for the YBBW as 9.1 years and 3.4 × 10⁻³ m²s^{− 1}, respectively.  相似文献   

Deep CTD Casts in the Challenger Deep,Mariana Trench   总被引：1，自引：0，他引：1  

Keisuke?TairaEmail author  Daigo?Yanagimoto  Shoji?Kitagawa 《Journal of Oceanography》2005,61(3):447-454

On 1 December 1992, CTD (conductivity-temperature-depth profiler) casts were made at three stations in a north-south section of the Challenger Deep to examine temperature and salinity profiles. The station in the Challenger Deep was located at 11°22.78′ N and 142°34.95′ E, and the CTD cast was made down to 11197 db or 10877 m, 7 m above the bottom by reeling out titanium cable of 10980 m length. The southern station was located at 11° 14.19′ N and 142°34.79′ E, 16.1 km from the central station, where water depth is 9012 m. CTD was lowered to 7014 db or 6872 m. The northern station was located at 11°31.47′ N and 142° 35.30′ E, 15.9 km from the central station, and CTD was lowered to 8536 db or 8336 m, 10 m above the bottom. Below the thermocline, potential temperature decreased monotonously down to 7300–7500 db beyond a sill depth between 5500 m and 6000 m, or between 5597 db and 6112 db, of the trench. Potential temperature increased from 7500 db to the bottom at a constant rate of 0.9 m°C/1000 db. Salinity increased down to 6020–6320 db, and then stayed almost constant down to around 9000 db. From 9500 db to the bottom, salinity increased up to 34.703 psu at 11197 db. Potential density referred to 8000 db increased monotonously down to about 6200 db, and it was almost constant from 6500 db to 9500 db. Potential density increased from 9500 db in accordance with the salinity increase. Geostrophic flows were calculated from the CTD data at three stations. Below an adopted reference level of 3000 db, the flow was westward in the north of Challenger Deep and eastward in the south, which suggests a cyclonic circulation over the Challenger Deep. Sound speed in Challenger Deep was estimated from the CTD data, and a relation among readout depth of the sonic depth recorder, true depth, and pressure was examined.  相似文献   

Benthic re-colonization in post-dredging pits in the Puck Bay (Southern Baltic Sea)   总被引：1，自引：0，他引：1  

Maria Szymelfenig  Lech Kotwicki  Boena Graca 《Estuarine, Coastal and Shelf Science》2006,68(3-4):489

The stage of benthic re-colonization at a site formed by sand extraction was investigated some 10 years after the cessation of dredging. The examined post-dredging pit is one of five deep (up to 14 m) pits created with a static suction hopper on the sandy, flat and shallow (1–2 m) part of the inner Puck Bay (the southern Baltic Sea). The topography of the dredged area makes a specific trap for different kinds of organic matter. It is created by the small areas of post-dredging pits as compared to their depths. As a result, organic matter accumulation leads to anaerobic conditions and hydrogen sulfide formation. Macrofauna was not found to occur permanently in the deepest part (11 m) of the cup-shaped depression, which was characterized by its small area (0.2 km²) and steep walls. However, permanent occurrence of meiofauna (max. 180 ind. 10 cm⁻², mainly Nematoda) was noted. Undoubtedly, re-colonization of benthic fauna assemblages, typical of shallow and sandy seabed of the Puck Bay, will not follow in a natural way in the area of post-dredging pits. Also, it could not be expected that the re-colonization sequence would result in the formation of a structure similar to that of the natural depression (the Kuźnica Hollow).  相似文献   

国内外海洋深层水资源利用现状及展望     

唐心强  党光耀  张丽清  深见公雄 《海洋湖沼通报》2007,(3):165-170

本文在介绍了海洋深层水的优良资源特性的基础上,系统介绍了世界各国在海藻养殖、鱼类养殖、蔬菜栽培、食品制造、酿酒、制冷、制盐、制冰及饮料生产等多方面应用海洋深层水的最新成果,并展望了今后海洋深层水研究开发的前景。  相似文献   

太平洋东部深海沉积物稀土元素地球化学   总被引：9，自引：0，他引：9  

刘季花 《海洋地质与第四纪地质》1992,12(2):33-42

通过对太平洋东部CC区深海沉积物的稀土元素研究发现:该区沉积物的REE含量较高,普遍具有较小的Eu正异常和较大的Ce负异常;不同类型沉积物中的稀土含量、比值和分布模式存在着差异,这种差异主要取决于沉积物组分的不同;沉积物的来源有自生源、火山源、生物源和陆源,稀土元素主要是通过自生组分富集的,区域上,Ce异常值低处,Eh值高,为强氧化环境区,也是南极底层流的流经路径,是多金属结核富集的有利地区。  相似文献   

Influence of Introduced CO<Subscript>2</Subscript> on Deep-Sea Metazoan Meiofauna     

Kevin R. Carman  David Thistle  John W. Fleeger  James P. Barry 《Journal of Oceanography》2004,60(4):767-772

An experiment was performed to determine the effect of injected CO₂ on the deep-sea (3200 m) meiofaunal community in the Monterey Canyon. Approximately 20 L of liquid CO₂ was added to each of three cylindrical corrals (PVC rings pushed into the seabed) that were arranged in a triangular array 10 m on a side. After a 30-day period, sediment cores were collected within an area exposed to the dissolution plume emanating from the CO₂ pools and from a reference site approximately 40 m away; cores were also collected from within two of the CO₂ corrals. Sediment cores were sectioned into 0–5, 5–10, and 10–20 mm layers. Abundances of major groups (harpacticoid copepods, nematodes, nauplii, kinorhynchs, polychaetes, and total meiofauna) were determined for each layer. CO₂ exposure did not significantly influence the abundances or vertical distributions of any of the major taxa. However, other evidence suggests that abundance alone did not accurately reflect the effect of CO₂ on meiofauna. We argue that slow decomposition rates of meiofaunal carcasses can mask adverse effects of CO₂ and that longer experiments and/or careful examination of meiofaunal condition are needed to accurately evaluate CO₂ effects on deep-sea meiofaunal communities. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

香港与珠三角地区海陆联合地震探测的数据处理   总被引：8，自引：4，他引：8  

夏少红  丘学林  赵明辉  叶春明  陈营华  徐辉龙  王平 《热带海洋学报》2007,26(1):35-38

介绍了香港与珠三角地区海陆联测地震数据处理的一般流程及方法,讨论了导航数据记录时间存在误差的问题及其解决方法,对数据处理程序进行了改进,使之更加通用化。提出了数据处理中需要改进之处,对较远的地震台站采用滤波、均衡、剪切等处理手段,突出弱震相,压制强噪音。广东和香港地区的大部分固定台站均可清晰识别出有效信号,这是首次利用固定台站记录到远距离海上气枪信号,最远接收距离达到240多公里,获得了较好的观测结果。  相似文献   

Intensification of Subtidal Surface Currents Over a Deep Channel in the Upper Chesapeake Bay     

Harry V. C. Wang  Shenn-Yu Chao 《Estuarine, Coastal and Shelf Science》1996,42(6):771-785

A three-dimensional hydrodynamic model of the Upper Chesapeake Bay was used to examine the nature and cause of an intensification of subtidal, southward surface current in the middle reaches of the basin. The deep navigation channel along the eastern boundary was found to be ultimately responsible. The deep channel allows the density and tidally-induced subtidal currents to intensify over it, producing the eastern intensification. Both mechanisms operate in the non-rotating limit and consequently do not diminish with vanishing effect of the earth's rotation. Density-induced forcing is predominantly baroclinic, generating a northward undercurrent in the deep channel and a southward current aloft which attenuates westward. Tidal forcing is mostly barotropic, producing southward mean current in the deep channel and return flow to the west. Historic data lend support to the model results.  相似文献   

胶北地块古元古代花岗伟晶岩脉的锆石SHRIMP ——Pb年代学特征及地质意义          下载免费PDF全文

张志刚 《山东国土资源》2020,36(4)

胶辽吉古元古代造山带是近年来国内古老造山带研究的热点地区,胶东半岛的胶北地块位于胶辽吉造山带南部,在胶北地块莱西一带发育了大量的古元古代荆山群变质地层,其中发育大量的花岗伟晶岩（脉）体,本次工作利用SHRIMP UPb测年技术,首次精确测定了花岗伟晶岩的形成时代为~1.84Ga,同时结合前人资料,确定了胶东半岛发育有与1.84Ga伸展作用相关的花岗伟晶岩类。通过与辽西地区所报道的花岗伟晶岩对比,认为二者在古元古代构造演化的过程中具有时空一致性。  相似文献