Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 112-118).

Thesis (Ph. D.)--University of Hong Kong, 1987.

No description available.

The seasonal pattern of ice motion in response to wind forcing and potential consequences to upwelling on the Mackenzie Shelf are considered using satellite-derived ice motion data from the National Snow and Ice Data Center and the NCEP 10 m wind data. The frequency of strong upwelling-favorable alongshore ice motion is high in early winter (November and December) compared to middle and late winter (January to May).For periods when the alongshore component of the wind is upwelling-favorable, the ratio of ice drift divided by wind speed on the Mackenzie Shelf is 0.024 in November and0.008 in March; we conjecture that this ratio decreases as winter progresses because the internal ice stress becomes stronger as both ice thickness and ice concentration increase. This constitutes a possible 10-fold decrease in the seasonal transmission of wind stress to the underlying water from November to March. This ratio in May (0.015) is higher than that in March. We suggest that it is because the internal ice stress becomes weaker as ice concentration decreases on the Mackenzie Shelf in May. Hence, under the same wind forcing, the potential for winter upwelling on Mackenzie Shelf may be enhanced if climate warming results in reduced ice thickness and/or ice concentration. Numerical model results show that the stress on the shelf could be reduced because of the internal ice stress from the pack ice over the deep ocean when the ice moves like a rigid body. We found that the model results are not realistic when the ice strength is 5,000 Nm-2. When the ice strength is 27,500 Nm-2, the model results are more realistic.

No description available.

No description available.

Oreaster reticulatus was studied in eight populations inhabiting shallow-water grassbeds and/or sand bottoms off Carriacou and Union Island in the Grenadines, and off St. Croix in the U.S. Virgin Islands (Caribbean). The sea star is fundamentally an omnivorous, microphagous substratum grazer: grassblades and/or surface sediments are accumulated beneath the disc by tube feet, and associated micro-organisms and detritus are ingested and digested by extraoral eversion of the cardiac stomach. Substratum grazing involves minimal foraging effort; however, the low concentration of particulate food resources necessitates frequent feeding. O. reticulatus also has a limited capacity for herbivory and can hydrolyze soluble algal cell contents. Opportunistic predation and scavenging of macrofauna may provide an important nutritional supplement, although capturable prey or carrion are generally unavailable or inaccessible to the sea star. Marked differences in individual size, storage and reproductive capacity among neighboring populations of O. reticulatus are attributed to differences in the quality and/or quantity of food resources. Intraspecific competition may limit productivity, particularly in isolated sand patches containing dense and extremely aggregated populations.

Saudi Arabia was the first Arab country to claim offshore jurisdiction and the first Middle Eastern state to define its offshore waters. This study examines the principal geographical factors which have resulted in the present Saudi maritime boundary. The semi-enclosed sea, islands, reefs, natural resources of the continental shelf, exclusive economic zone and coastline, can all be considered principal geographical factors that have influenced Saudi territorial waters policy. Islands, for example, play an effective role in increasing the area of Saudi internal waters, increasing the breadth of the territorial sea, straight baseline and the delimitation of maritime boundary in the Red Sea and the Arabian Gulf with opposite and adjacent states. Natural resources demanded the swift implementation of unique agreements, used later as an example worldwide. The author has drawn the 1958 Saudi straight baseline and a theoretical straight baseline based on the 1982 Convention and states practice. The territorial sea which is drawn on this basis along the Red Sea and the Arabian Gulf coasts, is affected by the presence of islands and reefs. The Saudi Exclusive Fishing Zone claimed by the 1974 decree gave the Kingdom the same right as the 1982 Exclusive Economic Zone (EEZ), but the Kingdom had to adapt the latter in order to gain more control over its resources and non-mineral activities. The importance of the 1949 Saudi decree can be found in the contribution made by Saudi Arabia to the development of the law of the sea, and to safeguarding the national hydrocarbon resources (natural gas and oil) on and below its seabed. Saudi Arabia engaged in several agreements, mainly in the Gulf, in order to define its boundary. This study has highlighted these agreements as a model which can be used in different parts of the world to solve similar disputes, and can be adopted as methods of maritime delimitation between opposite and adjacent states. The importance of the economic factor has been shown, along with security, as the main factor influencing the successful conclusion of such agreements, but where there is no such importance, the boundary may become less significant and by the absence of such motivation the boundary may not be defined. Saudi waters are a rich and highly important maritime area. This is based on the facts that Saudi Arabia has 30 per cent of the world seawater desalination plants; that the sea represents food, fuel and wealth to Saudi Arabia; and that the existence of huge deserts emphasises the importance of the sea.

Key processes affecting the transport of particulate trace metals in the coastal waters of the Irish and North Seas have been examined. Sample collection and experimentation was carried out on board R.R-S. Challenger in January 1992 (Irish Sea) and in December 1992 and November 1993 (North Sea). Particulate samples were digested in IM HCI and the concentrations of Ca, Cd, Co, Cu, Fe, Mn, Pb and Zn were determined, together with the 206/207Pb isotopic ratio. In the North Eastern Irish Sea the concentrations of suspended particulate trace metals were affected significantly by tidal processes, such that ebb tides transport particles of higher trace metal concentrations from the nearshore, while flood tides transport metal-depleted particles from offshore. This tidally-induced transport was confirmed by complementary 206/207Pb analyses, which showed the value of this technique in particle tracing. In the North Sea suspended particulate trace metal concentrations were higher adjacent to industrialised estuaries and high Pb concentrations were found m the Tyne/Tees region (in the range 200 - 340 ug g-1), in combination with low 206/207Pb suggesting an anthropogenic origin. Estimated fluxes of trace metals from the Humber Estuary to the North Sea were relatively small compared to the PARCOM inputs to the estuary. There was little evidence of interannual variability in these fluxes compared to those obtained in December 1988. Samples of end-members of the Humber Plume particle mixing series (estuary and cliffs) were used in radiochemical uptake studies, which indicated a response time of about 1 day for 109Cd, 137Cs and 65Zn to reach a new equihbrium. When the end-members were mixed together in various proportions they showed the uptake of 109Cd and 54Mn behaved non-additively. Settling of suspended particulate trace metals in the plume region was examined in unique experiments involving stable and radioisotopes. It was shown that trace metals were preferentially associated with different settling fractions. Lead was associated with slow settling particles whereas Cu was associated with particles settling more rapidly. The results presented in this dissertation allowed the development of a conceptual model for fine sediment transport for trace metals, which could be interfaced with established hydrodynamic models.

No description available.