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1.
The paper discussed the advantages and limitations of seismic signal detection on the ocean bottom. The need to create long-term seismic monitoring systems in areas of industrial development on the shelf and continental slope, as well as in areas with high seismic and tsunami hazards, is justified. The results of employing broadband bottom seismographs during expeditions of the Shirshov Institute of Oceanology of the Russian Academy of Sciences (IO RAS) are described. Autonomous broadband bottom seismographs with operational communication via satellite or radio channels are proposed for creating a global marine seismic network.  相似文献   

2.
Estuaries are often seen as important filters between land and the sea for inorganic and organic nutrients. This paper aims at estimating the estuarine fluxes of dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP) and dissolved silicate for the major oligothrophic and pristine rivers running into the Bothnian Bay (BB) and the Bothnian Sea (BS), the northern subarctic subbasins of the Baltic Sea. Long-term data sets for these rivers and their estuaries as well as for the BB and BS were analyzed to assess whether these estuaries are sinks for inorganic nutrients. Most studied estuaries can be characterized as salt wedge estuaries with little exchange between the fresh seaward-flowing river water and the inward-flowing seawater. Estimates of water transit times ranged between 1 and 14 days. In most estuaries of the BB, N-depleted river water meets P-depleted seawater during the growth period. These findings were corroborated by mixing diagrams showing that the inner areas of the estuaries were N-depleted in summer. In the BS, on the other hand, both rivers and seawater were mostly N-depleted during summer. Thus, for most estuaries of this region of the Baltic Sea, primary productivity is presumably lower than or equal to that of offshore. The low productivity is also reflected in the sediments. The coastal sediments did not differ from the offshore stations in accumulation rates as well as the content of organic matter and nutrients, indicating that estuarine nutrient burial is not always higher as normally observed in other temperate systems. Finally, the estuaries of the pristine rivers in the northernmost part of the BB import DIN during summer, whereas the estuaries of the rivers in the BS import DIP during winter, from the sea.  相似文献   

3.
A total of 6085 adult Trichoptera (excluding Hydroptilidae) representing 12 families, 31 genera, and 56 species were collected by a combination of Malaise net and light trapping from July 1998 to July 1999 at three hill‐country sites of contrasting catchment land use (100% native forest, a pasture site with native forest headwaters, and 100% pasture) in the Waikato, northern New Zealand. Forty‐eight species of Trichoptera were collected from Malaise nets and 45 species from light traps. Eleven species of Trichoptera were only ever collected from the Malaise nets and seven species from only the light traps. At the native forest site, Malaise nets collected more species and taxa of conservation interest than did light traps, possibly reflecting diurnal activity or non‐attraction to light by some species. Several species of Trichoptera showed site specificity and most of these were found at the native forest site. Twenty‐eight species were active for at least 6 months of the year with at least four species active all year. A minimum overnight air temperature of at least 9°C was required to induce Trichoptera flight activity, but large‐scale flight activity may require temperatures greater than 14°C. Trichoptera with free‐living and net spinning larvae exhibited extended flight periods, and for three species examined there were bi‐modal activity peaks. Adult caddisflies with cased larvae which grazed on epilithic food resources generally had reduced flight periods and one species had a well‐defined, synchronous periodicity. These findings suggest flight periodicity may partly be a functional response to larval food availability.  相似文献   

4.
The landing obligation recently adopted by the European Union's (EU) Common Fisheries Policy aims to eradicate discards in EU fisheries. The objective of this paper is to investigate the potential social and economic impacts of the discard ban in European small-scale fisheries (SSF) and the critical factors for its successful implementation. An exhaustive systematic literature review and a stakeholder consultation were carried out in order to (i) collect detailed information about current knowledge on discards in EU SSF and gauge stakeholder perceptions about potential impacts of the discard ban in European SSF, (ii) examine the capacity of the SSF industry to implement the discard ban, and (iii) explore the limits and feasibility of implementing such a measure.The results of this study show that little attention has been given by the scientific community to discards in EU SSF. Indeed, the systematic literature review shows that this problem is relatively unexplored in the EU. In addition, the effectiveness of a discard ban in industrial fisheries is still unclear, mainly because discard data are not systematically collected by fisheries authorities. Stakeholders mostly perceive that the new landing obligation was developed with industrial fisheries in mind and that compliance with the landing obligation in EU SSF will be difficult to achieve without high economic costs, such as those related to the handling and storage of unwanted fish on board.  相似文献   

5.
The exposed area of intertidal zone varies with tidal water level changes. If intercomparisons of satellite images are adopted as a method to determine geomorphological changes of the intertidal zone in response to accretion or erosion processes, then the e?ect of water level variations must be evaluated. In this study, two Landsat TM images overpassing the central Jiangsu coastal waters on 2 January and 7 March 2002, respectively, were treated by the changing detection analysis using Image Di?erencing and Post-classiˉcation Comparison. The simultaneous tide level data from four tide gauge stations along the coast were used for displaying the spatial variations of water levels and determining the elevations of waterlines. The results show that the spatial variations of water levels are highly signiˉcant in the central Jiangsu coastal waters. The huge di?erences of tidal land exposure patterns between the two imaging times are related mainly to the spatial variations of tidal water levels, which are controlled by the di?erences in tidal phases for di?erent imaging times and the spatial variations of water level over the study area at each imaging time. Under complex tidal conditions, e.g., those of the central Jiangsu coastal waters, the tide-surge model should be used to eliminate e?ectively the e?ects of water level variations on remote sensing interpretation of geomorphological changes in the intertidal zone.  相似文献   

6.
In 2008, 55 of the world's largest ports voluntarily adopted the World Ports Climate Declaration (WPCD) and the International Association of Ports and Harbours committed to long-term work on implementation through the World Ports Climate Initiative (WPCI). This article assesses the work of WPCI since 2008 and makes five recommendations that, if implemented, could support efforts to reduce the climate and environmental impacts of port operations and international shipping. In particular, as the impetus for the WPCD came from a port city – Rotterdam – and their engagement with a transnational municipal network – the C40 Large Cities Climate Leadership Group – the paper considers the role of cities and transnational municipal networks in governance, and the potential for cities to play a more active and influential role in the maritime sector. The article presents an overview of literature on the role and function of transnational municipal networks, the background and development of the WPCD, analysis of the work of WPCI, and a discussion concerning the potential of cities and transnational municipal networks to support and add value to WPCI or similar initiatives in the maritime sector. This informs the conclusions and recommendations to marine policy-makers and port stakeholders.  相似文献   

7.
In this paper the seasonal variation and structural characteristics of the sea/ land breeze in the northern coastal area of" Shandong Peninsula are studied in two ways: one is the analysis of the observed wind data, and the other is numerical simulation and experiments. Firstly, the hour to hour wind data through the year 1984 at Longkou Meteorological Station and Yantai Oceanographic Station are analysed through energy spectra and hodograph. It is revealed from the analysed results that the effects of the sea/ land breeze in the area are notable in spring, summer and fall, especially in May. However, in winter the effects of sea / land breeze are not obvious. because the cold noitherly is prevailing. Secondly, a two-dimensional non- linear model of primitive equations is used to study the sea / land breeze circulation in May in the area. The results of numerical simulation consist basically with the analysed results of the observed sea / land breeze. A reasonable theoretical structure of the sea / land  相似文献   

8.
Faecal contamination of rural streams is of increasing concern in New Zealand. This study assessed hill‐country streams in the Whatawhata district that were impacted by pastoral farming, indigenous forest, or Pinus radiata forest; by measuring Escherichia coli bacteria at 14 sampling sites fortnightly for 2 years. E. coli concentrations were highest in streams flowing through grazed pasture. In both years there was a noticeable seasonal pattern in all streams irrespective of land use, with highest bacterial concentrations in summer and autumn and lowest in winter and early spring. There was no obvious correlation between E. coli concentration and rainfall or stream flow. In those streams impacted by a change in land use from pastoral to pines during the study, E. coli concentration fell rapidly and remained at levels lower than those in streams impacted by either indigenous or 7‐year pine forests. As E. coli was detected in all but two samples, the water in these streams is not suitable for human consumption. The pastoral streams consistently failed to meet stock drinking‐water guidelines (median concentration not greater than 100 E. coli 100 ml–1) and the forest streams failed to do so in summer. Twenty‐eight percent of pastoral samples, 25% of indigenous forest samples, 14% of 7‐year pine forest samples, and 5% in New Pines stream samples (after planting) had E. coli concentrations associated with a high level of risk for contact recreation (>500 E. coli 100 ml‐1) and the high concentrations usually occurred in summer.  相似文献   

9.
Two earthquakes were recorded by 20 ocean bottom seismometers (OBS) deployed in the Southwest Indian Ridge (SWIR) area during a three-dimensional seismic survey in 2010. Their magnitudes (both M b = 4.4) and hypocenters have been determined by National Earthquake Information Center (NEIC) only using land seismic stations onset times. After the frequency analysis and the band-pass filtering of the OBSs’ data, 7 and 13 P-phase onset times from OBSs were successfully picked for these two events, respectively. Then these two events were relocated by HYPOSAT program with onset times together from OBSs and land seismic stations using different velocity models. These relocation experiments confirm both the importance of adding OBSs’ onset data and the need to apply a local oceanic velocity model for the location of these two events happened on the SWIR. This research has accumulated a wealth of experience for earthquakes observation and research using OBSs in the ocean.  相似文献   

10.
The formation of the fields of surface winds over the Black Sea occurs under the action of numerous physical factors. One of the most important factors is the monsoon mechanism connected with the seasonal variations of buoyancy contrasts over the sea and surrounding land. To separate the effects caused by this mechanism, we performed and described the numerical experiments aimed at the evaluation of the sensitivity of the regional model of atmospheric circulation to the variations of land–sea temperature contrasts. It is shown that the influence of these effects is restricted to the lower part of the atmosphere. The presented estimates of the climatic fields of disturbances enable us to describe the monsoon mechanism specifying the seasonal variability of the field of vorticity of the wind velocities and, as a consequence, the seasonal variability of the large-scale circulation of waters in the Black Sea.  相似文献   

11.
Aims and Scope     
《中国海洋工程》2004,18(2):F003-F003
  相似文献   

12.
Aims and Scope     
《中国海洋工程》2005,19(4):F0003-F0003
China Ocean Engineering takes as its prime function the integration of new research concepts, equipment, technology, materials and structures and other scientific advances within the field of ocean engineering, with particular reference to developments in China. Tne Journal is concerned with all engineering aspects involved in the exploration and utilization of ocean resources, such as offshore engineering, coastal engineering, dive and salvage, utilization of marine energy, resourees and underwater engineering.  相似文献   

13.
Aims and Scope     
《中国海洋工程》2006,20(2):F0003-F0003
China Ocean Engineering takes as its prime function the integration of new research concepts,equipment,technology,materials and structures and other scientific advances within the field of ocean engineering,with particular reference to developments in Chi…  相似文献   

14.
Aims and Scope     
Being an intcrnational journal,China Ocean Engineering takes as its prime function the integration of new researchconcepts,equipment,technology,materials and structures and other scientific advances within the field of  相似文献   

15.
Aims and Scope     
正China Ocean Engineering takes as its prime function the integration of new research concepts, equipment, technology, materials and structures and other scientific advances within the field of ocean engineering, with particular reference to  相似文献   

16.
Aims and Scope     
《海洋工程》2006,24(2):F0003-F0003
China Ocean Engineering takes as its prime function the integration of new research concepts,equipment,technology,materials and structures and other scientific advances within the field of ocean engineering,with particular reference to developments in Chi  相似文献   

17.
Aims and Scope     
《海洋工程》2005,23(4):F0003-F0003
由中国海洋工程学会主办,南京水利科学研究院承办,大连理工大学海岸和近海工程国家重点实验室协办的第十二届中国海岸工程学术讨论会于2005年10月16-19日在云南省昆明市召开。邱大洪名誉理事长、谢世楞、严以新、李润培、李京武、左其华等副理事长出席了会议。全国从事海洋工程研究包括高等院校、设计、科研、建设和施工等39个部门的近百名代表参加了学术交流。17日上午,严以新副理事长主持了开幕式,并致开幕词;窦希萍副秘书长作了学会近两年来的工作总结。严以新和左其华教授分别主持了大会主题报告。中国科学院院士邱大洪教授论述了沿海海…  相似文献   

18.
Aims and Scope     
《海洋工程》2007,25(2):F0003-F0003
China Ocean Engineering takes as its prime function the integration of new research concepts, equipment, technology, materials and structures and other scientific advances within the field of ocean engineering, with particular reference to developments in  相似文献   

19.
Aims and Scope     
《中国海洋工程》2007,21(2):F0003-F0003
China Ocean Engineering takes as its prime function the integration of new research concepts, equipment, technology, materials and structures and other scientific advances within the field of ocean engineering, with particular reference to developments in China. The Journal is concerned with all engineering aspects involved in the exploration and utilization of ocean resources, such as offshore engineering, coastal engineering, dive and salvage, utilization of marine energy resources and underwater engineering.[第一段]  相似文献   

20.
Aims and Scope     
China Ocean Engineering takes as its prime function the integration of new research concepts, equipment,technology, materials and structures and other scientific advances within the field of ocean engineering, with particular reference to developments in China.  相似文献   

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