Ocean Pacific

Important ore deposits are found in Zaire, Morocco, and Ganada. The U.S. Geological Survey has announced that the bottom of the north central Pacific Ocean may have cobalt-rich deposits at relatively shallow depths in water close to the the Hawaiian Islands and other U.S. Pacific territories. 

Fig. 2. Distribution of ( ) known and (o) suspected metalliferous sulfide deposits and active hydrothermal vents in the Pacific Ocean (42).

P. Halbach, G. Friedrich, and U. von Stackelberg, eds.. The Manganese Nodule Belt of the Pacific Ocean, Stuttgart, Ferdinand Enke Vedag, 1988. 

Ocean Nodules. A less conventional copper resource consists of deep-sea ferromanganese nodules. These nodules are primarily manganese, but some deposits contain over 1% copper. The nodules occur at many ocean sites, but the most valuable deposits are found in the Pacific Ocean. Although a number of companies are studying methods for recovering values from this source, copper resources from nodules must be considered tentative. World resources are estimated at 0.7 biUion metric tons (8) (see Ocean raw materials). 

You have been asked to prepare an outline design for the pressure hull of a deep-sea submersible vehicle capable of descending to the bottom of the Mariana Trench in the Pacific Ocean. The external pressure at this depth is approximately 100 MPa, and the design pressure is to be taken as 200 MPa. The pressure hull is to have the form of a thin-walled sphere with a specified radius r of 1 m and a uniform thickness t. The sphere can fail in one of two ways ... 

In the corrosion protection of marine structures, it is often found that the corrosion rate decreases strongly with increasing depth of water, and protection at these depths can be ignored. Investigations in the Pacific Ocean are often the source of these assumptions [7], However, they do not apply in the North Sea and other sea areas with oil and gas platforms. Figure 16-1 is an example of measurements in the North Sea. It can be seen that flow velocity and with it, oxygen access, is responsible for the level of protection current density. Increased flow velocity raises the transport of oxygen to the uncoated steel surface and therefore determines the... 

Volcanic sources of the free element are also widespread they have been of great economic importance until thi.s century but are now little used. They occur throughout the mountain ranges bordering the Pacific Ocean, and also in Iceland and the Mediterranean region, notably in T irkey, Italy and formerly also in Sicily and Spain. 

Joint ventures such as the revitalization of the Panama Canal Railway—a 47-mile railroad running parallel to the Panama Canal and connecting ports on the Atlantic and Pacific Oceans—should be more common. Kansas City Southern Railroad and Mi-... 

Variability of Seawater Vertical sections through seawater showing the distribution of temperature, salinity, and oxygen for the Pacific Ocean and Western Atlantic Ocean are shown in Figures 21.3 and 21.4. The global variability of natural seawater and its effects on corrosion have been reviewed in particular with respect to seasonal variation of temperature, salinity, oxygen and pH in the Pacific surface water. Data is also given on... 

North latitude Atlantic ocean Indian ocean Pacific ocean South latitude Atlantic ocean Indian ocean Pacific ocean... 

Little scientific examination of the deterioration of materials at depth has been undertaken except that by the US Naval Civil Engineering Laboratory and Naval Research, Laboratory. The results of this work were reported by Reinhart in 1966 and more recently the work has been reviewed by Kirk . Typical corrosion data for a selection of metals exposed in the Pacific Ocean at several sites and for different times are shown in Table 2.19 and are compared with results obtained in surface waters at Wrightsville Beach by International Nickel Inc. 

Fig. 21.3 Vertical sections showing distribution of temperature, salinity, and oxygen in the Pacific Ocean, approximately along the meridian of I70°W. (After Sverdrup, H. U., Oceanography for Meteorologists, Allen and Unwin (1945))...

Comparison with other Studies. How do the results of our investigation compare with similar studies Our results corroborate the data provided in a similar study of the effect of UV-B on primary productivity in the southeastern Pacific Ocean (35). In the latter study, it was noted that enhanced UV-B radiation caused significant decreases in the productivity of surface and deep samples. Compared to ambient, primary productivity decreased with increasing doses of UV-B. In another study in which in situ experiments using natural Antarctic phytoplankton populations, it was noted that incident solar radiation significantly depressed photosynthetic rates in the upper 10-15 meters of the water column (36). It was also found that the spectral region between 305 and 350 nm was responsible for approximately 75 percent of the overall inhibitory effect. 

Many hydrologic reservoirs can be further subdivided into smaller reservoirs, each with a characteristic turnover time. For example, water resides in the Pacific Ocean longer than in the Atlantic, and the oceans surface waters cycle much more quickly than the deep ocean. Similarly, groundwater near the surface is much more active than deep reservoirs, which may cycle over thousands or millions of years, and water frozen in the soil as permafrost. Typical range in turnover times for hydrospheric reservoirs on a hillslope scale (10-10 m) are shown in Table 6-4 (estimates from Falkenmark and Chapman, 1989). Depths are estimated as typical volume averaged over the watershed area. 

Fig. 9-4 Photograph of landslides (soil avalanches) that occurred following earthquakes in Panama on July 17,1976, near Jaque. In the background is a bay of the Pacific Ocean. The effects of this earthquake are described by Garwood et al. (1979), who estimated that about 42 km (about 10%) of the region near the epicenter of the earthquake was devegetated. The bedrock is mostly island-arc basalts and andesites. (Photography by N. C. Garwood.)...

The area, volume and average depth of the ocean basins and some marginal seas are given in Table 10-1. The Pacific Ocean is the largest and contains more than one-half of the Earth s water. It also receives the least river water per area of the major oceans (Table 10-2). Paradoxically it is also the least salty (Table 10-3). The land area of the entire Earth is strongly skewed toward the northern hemisphere. 

Fig. 10-4 Average temperature/salinity diagrams for Pacific Oceans. (Reproduced with permission from G. L. Oceanography," pp. 138-139, Pergamon Press.)...

Fig. 10-12 The A C values of the cores of the North Atlantic, Pacific, and Indian Ocean deep waters. The oldest waters are encountered near 40°N in the Pacific Ocean. (Modified with permission from M. Stuiver et al. (1983). Abyssal water carbon-14 distribution and the age of the world oceans. Science 219 849-851, the AAAS.)...

Fig. 10-20 Observed depth profiles of (a) phosphate, (b) dissolved inorganic carbon (TC), (c) alkalinity (TA), and (d) oxygen for the Atlantic, the Indian, and the Pacific Oceans as indicated. Data are from GEOSECS stations within 5° of the Equator in each ocean. (Modified from Baes et al. (1985).)...

Oceanic circulation. The process of ocean circulation described earlier yields an ocean circulation pattern that results in progressively older deep water as the water passes, in sequence from the Atlantic, Indian, to the Pacific Ocean. Surface water returns relatively quickly to the place of origin for the deep water. 

Coale, K. H., Johnson, K. S., Fitzwater, S. E. et al. (1996). A massive phytoplankton bloom induced by an ecosystem-scale iron fertilization experiment in the equatorial Pacific Ocean. Nature 383, 495-501. 

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