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Marine Geology Phần 8

Tham khảo tài liệu 'marine geology phần 8', khoa học tự nhiên, công nghệ môi trường phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | MARINE GEOLOgy Figure 167 Wind turbines at San Gorgonio California. Photo courtesy U.S. Department of Energy the bottom of a chamber and forces it into a vertical tower where the compressed air spins a turbine that drives an electrical generator. Tidal power is another form of energy. Gulfs and embayments along the coast in most parts of the world have tides exceeding 12 feet called macrotides. Such tides depend on the shapes of bays and estuaries which channel the wavelike progression of the tides and increase their amplitude.The development of exceptionally high tidal ranges in certain embayments is due to the combination of convergence and resonance effects within the tidal basin. As the tide flows into a narrowing channel the water movement constricts and augments the tide height. Generating electr icity using tidal power involves damming an embayment letting it fill with water at high tide and then closing the sluice gates at the tidal maximum when a sufficient head of water can drive the water 224 SEA RICHES turbines. Many locations with macrotides also experience strong tidal currents which could be used to drive turbines that rotate with both the incoming and outgoing seawater to generate electricity. Thermonuclear fusion energy Fig. 168 is both renewable and essentially nonpolluting. The fuel for fusion is abundantly available in seawater. The energy from the fusion of deuterium a heavy isotope of hydrogen in a pool of water 100 feet on each side and 7 feet deep could provide the electrical needs of one-quarter of a million people for an entire year. Fusion is safe. Its by-products are energy and helium a harmless gas that escapes into space. Figure 168 An artist s rendition of the International Fusion Experiment ITER at Princeton New Jersey. Photo courtesy U.S. Department of Energy 225 MARINE GEOLOgy HARVESTING THE SEA The world s fisheries are in danger of collapsing from overfishing. The United States created its marine sanctuaries program in 1972 when