Word: earthing
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Dates: during 1950-1959
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Crack in the Ridge. Lament's theory of the earth started taking shape several years ago when electronic depth-measuring equipment spotted a peculiar crack in the top of the Mid-Atlantic Ridge, the strange underwater mountain range that snakes down the center of the North and South Atlantic. Other explorations proved that the crack followed the ridge's top faithfully from north to south...
Vema's discovery of a crack following the top of the ridge gave Wegener's theory a new round of attention. The curving crack might be a rift, a familiar geological feature that indicates the earth's crust has been under tension and has pulled apart...
...depth charts, sometimes on old ones. When they noticed that many shallow earthquakes came from under it, they searched seismograph records for similar earthquake centers in unsounded parts of the oceans. By last week the Lamont men could trace the cracks 40,000 miles clear around the earth (see map). As in the Atlantic, the cracks generally follow the tops of rises in the ocean bottom. They stay midway between large land masses, but in a few places they run ashore, forming, for instance, the steep-sided Jordan Valley and the famous rift system in East Africa which contains both...
...Continent. Lamont men think the cracks may be proof that the continents indeed drifted away from each other, and are still drifting. Dr. Ewing recalled a theory of Venig Meinesz, who suggested that the early earth may have lacked the dense central core that it has today. Its hot, fluid inside material could circulate unhampered in a single "cell," rising to the surface on one side of the sphere and sinking down on the opposite side after cooling by radiation into space and getting heavier. When this had gone on long enough, all the light rock on the earth...
Later, according to Meinesz, the earth formed a dense core that stopped the single-cell circulation. Then, the molten inner material was forced to circulate in smaller cells which reached the surface in several places. This spelled trouble for the single continent. One of the streams of material rose beneath it, split it asunder and moved the pieces apart...