The linearisation of three dimensional drag force in random seas with current     

R.S. Langley 《Applied Ocean Research》1984,6(3):126-131

A frame invariant linearisation method for three-dimensional drag force in random seas with current is presented. Numerical results are compared with those obtained from a commonly used linearisation method which is based on a non-frame invariant approximation to the drag force. Significant differences are discovered and the present method is found to show closer agreement with computed time histories of the true drag force.  相似文献   

Approaches to the study of cheniers along the coastline of the Soviet Union     

Yurii D. Shuisky 《Marine Geology》1989,90(4):289-296

With the very extensive coastline in the north and northeast and the relatively shorter coastlines in the south, cheniers in the USSR can occur in a great variety of climatological conditions ranging from subarctic to subtropical. Cheniers in the USSR have been studied since approximately 1900, the investigations being mainly concerned with the palaeogeographical aspects. Since the 1960's, investigations have focussed on contemporary morphodynamics. Chenier formation appears to depend largely on the relative influence that marine and fluvial factors have on the formation of marginal deltaic plains. Research in this field is briefly reviewed.  相似文献   

The Bengal Fan: Some preliminary results from ODP drilling     

Dorrik A. V. Stow  James R. Cochran  ODP Leg Shipboard Scientific Party 《Geo-Marine Letters》1989,9(1):1-10

Three deep holes, with a maximum penetration of 960 m below sea floor, were drilled into the distal Bengal Fan just south of the equator during ODP Leg 116. The entire section recovered is dominated by sandy silt and mud turbidites derived from the Ganges Delta and from the continental margin of the western Bay of Bengal, interbedded with thin pelagic clays and with biogenic turbidites probably from a local sea mount source. The effects of Hi-Malayan uplift, sea level fluctuations, local tectonics, and fan channel/lobe processes have closely interacted to produce the observed sedimentary record of the past 17 million years since the early Miocene.Coauthors include: James R. Cochran, Lamont-Doherty Geological Observatory (Co-chief scientist); Dorrik A. V. Stow, Nottingham University, England (Co-chief scientist); Christian A. Auroux, Texas A & M University, USA (ODP staff scientist); Kazou Amano, Ibaraki University, Japan; Peter S. Balson, British Geological Survey, Keyworth, Notts, England; Jacques Boulegue, Pierre & Marie Curie University, Paris, France; Garrett W. Brass, University of Miami, Florida, USA; Jeffrey Corrigan, University of Texas, Austin, USA; Stefan Gartner, Texas A & M University, USA; Stuart A. Hall, University of Houston, Texas, USA; Silvia Iaccarino, University of Parma, Italy; Toshio Ishizuka, University of Tokyo, Japan; trena Kacmarska, Mount Allison University, New Brunswick, Canada; Heidemarie Kassens, Kiel University, West Germany; Gregory Leger, Dalhousie University, Halifax, Nova Scotia, Canada; Franca Proto Decima, University of Padova, Italy; C. V. Raman, Andhra University, Visakhapatnam, India; William W. Sager, Texas A & M University, USA; Kozo Takahashi, Woods Hole Oceanographic Institution, USA; Thomas Thompson, 580 Euclid Ave, Boulder, Colo, USA; Jean-Jacques Tiercelin, University of Bretagne, Brest, France; Mark Townsend, University of Nottingham, England; Andreas Wetzel, Tubingen University, West Germany; N. P. Wijayananda, National Aquatatic Resource Agency, Colombo, Sri Lanka; and Colin Williams, Lamont-Doherty Geological Observatory.  相似文献   

Descriptive Analysis and Classification of Benthic Communities in Some Mediterranean Coastal Lagoons (Central Italy)   总被引：3，自引：0，他引：3  

M. F. Gravina  G. D. Ardizzone  F. Scaletta  C. Chimenz 《Marine Ecology》1989,10(2):141-166

Abstract. Benthic samples were taken seasonally at 32 stations in five coastal lagoons of Central Italy (Fogliano, Monaci, Caprolace, Fondi, and Lungo) during a two-year period (1982–1984). Composition and distribution of benthic populations in each lagoon as well as seasonal trends of species richness, density, diversity, and redundancy are presented and discussed.
The faunal differentiation appeared to be mainly due to the different degree of water exchange, both with marine and continental systems.  相似文献   

Trace metals in selected organisms from the Adriatic sea     

D. Martin i&#x;  Z&#x;. Kwokal  M. Branica  M. Stoeppler 《Marine Chemistry》1987,22(2-4)

Extensive surveys were made to establish the concentrations of several metals (Zn, Cd, Pb, Cu and Hg) in various marine organisms from different parts of the Adriatic Sea in the period from 1979 to 1985. The results obtained are based on analyses which were performed in conjunction with carefully tested procedures. Proper sampling, sample storage, treatment of samples and final analytical determination has excluded artefacts which would influence the accuracy, or cause contamination and/or trace metal losses.The metal concentrations in shellfish from the coastal areas of the Adriatic Sea are in the range of the lowest values obtained for similar organisms from other localities throughout the Mediterranean Sea. Special attention has been paid to the anthropogenic influence on trace metal concentrations in organisms living in the vicinity of domestic sewage and/or industrial waste-water outflows.  相似文献   

AN ECOSYSTEM MODEL ANALYSIS OF THE EFFECT OF MINE TAILINGS ON THE EUPHOTIC ZONE OF A PELAGIC ECOSYSTEM   总被引：1，自引：0，他引：1  

T. R. PARSONS  T. A. KESSLER  LI GUANGUO 《海洋学报(英文版)》1986,5(3):425-436

A computer analysis was performed on experimental results obtained when mine tailings were added to seawater. The Mixed Upper-Layer Ecotrophie Simulation (MULES) model was tested by changing the extinction coefficient and the abundance of heterotrophic zooflagellates. Increasing the extinction coefficient resulted in a delay of phytoplankton growth, an increase in zooplankton standing stock and better growth of autotrophic flagellates compared with diatoms. Zooflagellates in the ecosystem influence the growth of zooplankton; secondary production by zooplankton was markedly depressed at low levels of zooflagellates. These results are believed to be of general significance for the diagnosis of suspended sediment effects on planktonic ecosystems.  相似文献   

A new methodology developed by cetena to assess the seakeeping behaviour of marine vessels     

B. Chil  G. Sartori  R. Santos 《Ocean Engineering》1986,13(3)

The paper describes an analytical method to determine an operability index for a marine vehicle when its geometric characteristics, the geographical area in which the vessel is supposed to operate, and the limiting criteria for operations are known. The computer program based on strip theory provides reliable results not only for conventional hullforms, but also for catamarans, offshore vehicles, etc. The results are presented in the form of figures for different vessels, namely, crane barge, naval vessels and SWATH type catamarans. The authors are of the opinion that the proposed method would provide the designer with a valid tool to improve the seakeeping qualities of a vessel, while taking into account the limiting conditions imposed due to seaway operations.  相似文献   

Effects of taxonomic uncertainty on species diversity indices     

R.S.S. Wu 《Marine environmental research》1982,6(3):215-225

As a result of taxonomic uncertainty, generic and higher taxonomic ranks (family, order, class or phylum) are often treated as units in calculating diversity indices, instead of species. In this paper, the errors introduced by such practices are examined for various diversity indices (Shannon - Wiener Index, Maximum Information Index, Evenness, Margalef's Species Richness Index and Hurlbert's Probability of Interspecific Encounter). The use of higher taxonomic ranks may invalidate comparison of diversity indices. In a single study, substantial error and erroneous conclusion may arise, even if consistent practices are adopted.  相似文献   

Geotechnical aspects of fine-grained mass flow deposits: California Continental Borderland     

F. J. Hein  D. S. Gorsline 《Geo-Marine Letters》1981,1(1):1-5

Seismic reflection profiling demonstrates the importance of mass movement in the north-central California Borderland. Bulk properties of surficial hemipelagic sediments in the Santa Barbara, Santa Cruz, and San Nicolas basins show that different types of mass-transported sediments have different properties, although their general sedimentologic characteristics are very similar. Slump deposits have moderate water contents (48% wet weight basis), high plasticity indices (46%), and moderate activities (1.6). For debris flows these values are low: 28%, 5%, and 0.3, respectively, and for other types (liquefied flow, mudflows, and turbidities) the values are high: 54 to 63%, 49 to 58%, and 1.2 to 1.5, respectively.  相似文献   

Sea-structure interaction for tripod-type steel gravity platform     

M. Berta  A. Blandino  D. Marcon  A. Paruzzolo 《Applied Ocean Research》1981,3(3):113-118

The paper deals with a numerical integrated procedure to calculate the effects of the interaction between sea waves and a tripod-type steel gravity platform. The main aspects to be taken into account for a reliable wave loading analysis of such a new type of platform are emphasized. Among them, the field perturbation effect due to the large bodies presence is analysed. Finally, some principal results in terms of structure global loads obtained by the numerical integrated procedure are presented.  相似文献