Broad ocean area

The Hydroacoustic Monitoring Network will consist of six underwater hydrophone stations and five island-based stations (T-phase stations). The hydrophones will detect signals from underwater explosions that readily propagate to great distances in the ocean sound channel. The less sensitive but much less expensive island stations will detect seismic signals that are generated by a hydroacoustic wave when it strikes an island. Sensitivity in the broad ocean areas (a likely place for a clandestine test) is expected to be far less than 1 kt, with localization to within 1000 km and with a source depth estimate. These capabilities are for events detected by three or more stations. 

A circumnavigation of the world s oceans between 1978-1980 (18), further indicated that broad expanses of the Atlantic, Pacific, and Indian Oceans away from major tanker lanes and shipping routes contained little or no tar, whereas tar pollution was prevalent in the Mediterranean, Java Sea and Red Sea, and in western European and Northwest African coastal areas. 

Sea-salt inputs are common in coastal regions. These salts have been introduced into the marine atmosphere from bubble bursting and breaking waves and are deposited on land with rain and dust fall. Small amounts of sea-salts are, however, also present in rainwater of central continental areas, thousands of miles from the sea. Sea-salt inputs have broadly similar, predominantly sodium chloride (NaCl), chemistry to the seawater from which they were derived. Thus, sodium or chloride ions can be used as a measure of sea-salt inputs to rainwater. Chloride concentrations in rain falling on oceanic islands are around 200pmolh, rain within 100 km of coastal continental areas contains around 10-100 pmolT1, while further inland chloride concentrations fall below 10 nmol I, but not to zero. 

Pacific Ocean As shown in, nodules are abundant in the Pacific Ocean in a broad area, called the Clarion-Clipperton Zone, between about 6°N and 20°N, extending from approximately 120°W to 160°W. The limits of the area are largely determined by sedimentation rates. Nodules are also locally abundant further west in the Central Pacific Basin. Sediments in the northern part of the areas of abundant nodules in the North Pacific are red clays with accumulation rates of around 1 mm per thousand years whereas in the south they are siliceous oozes with accumulation rates of 3 mm per thousand years, or more. 

The South China Sea (SCS) is the largest semi-enclosed marginal sea off East Asia in the western tropical Pacific Ocean, spreading from the equator to 20° N and spanning zonally about 15° in longitude with a broad shelf and a deep basin and an area of about 3.5x10 km (Fig. 1.35, Liu QY et al., 2008). The size is about 3,330 km from north to the south and 1,670 km from east to west. SCS lies between the South China coast and the maritime continent, located between the Asian land mass to the north and west, the Philippine Islands to the east, Borneo to the southeast, and Indonesia to... 

A broad distinction must be made between seawater in the tropics and that in more temperate climates. Temperate seawater is much less corrosive because the ocean temperature is much lower and the magnesium salts are therefore sufficient to act as inhibitors. There is a gradual change from one condition to the other. Harbor waters in India and other tropical areas were compared by Deshmukh (1987) local biofouling affects results. Tchemov and Ilyin (1987) regard calcium carbonate content as more signiEcant than temperature in the Indian Ocean. Higher corrosion rates are likely in polluted seawater. 

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