Harry Hammond Hess
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Harry H. Hess was an American geophysicist who played a crucial role in developing the theory of plate tectonics. In 1960, Hess proposed the hypothesis of seafloor spreading. His theory suggested that new oceanic crust forms at mid-ocean ridges and spreads outward. This process causes continents to drift apart and explains why the oldest oceanic crust is relatively young, not exceeding 200 million years old. Hess's model, which described rising mantle material at ridges and descending material at trenches, revolutionized geological understanding.123
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- continental drift
…early 1960s, the American geophysicist Harry H. Hess proposed that new oceanic crust is continually generated by igneous activity at the crests of oceanic ridges—submarine mountains that follow a sinuous course of about 65,000 km (40,000 miles) along the bottom of the major ocean basins. Molten rock material from Earth’s…
Read More…early 1960s, the American geophysicist Harry H. Hess proposed that new oceanic crust is continually generated by igneous activity at the crests of oceanic ridges—submarine mountains that follow a sinuous course of about 65,000 km (40,000 miles) along the bottom of the major ocean basins. Molten rock material from Earth’s…
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seafloor spreading…proposed by the American geophysicist Harry H. Hess in 1960. On the basis of Tharp’s efforts and other new discoveries about the deep-ocean floor, Hess postulated that molten material from Earth’s mantle continuously wells up along the crests of the mid-ocean ridges that wind for nearly 80,000 km (50,000 miles)…
Read More…proposed by the American geophysicist Harry H. Hess in 1960. On the basis of Tharp’s efforts and other new discoveries about the deep-ocean floor, Hess postulated that molten material from Earth’s mantle continuously wells up along the crests of the mid-ocean ridges that wind for nearly 80,000 km (50,000 miles)…
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plate tectonicsHess’s seafloor-spreading modelThe existence of these three types of large, striking seafloor features demanded a global rather than local tectonic explanation. The first comprehensive attempt at such an explanation was made by Harry H. Hess of the United States in a widely circulated manuscript…
Read MoreThe existence of these three types of large, striking seafloor features demanded a global rather than local tectonic explanation. The first comprehensive attempt at such an explanation was made by Harry H. Hess of the United States in a widely circulated manuscript…
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