Large warm spot in the Pacific.Large warm spot in the Pacific While conducting temperature and salinity measurements off the coast of Oregon in the summer of 1986, oceanographer Edward. T. Baker discovered an unusual warm spot in the ocean. The mere existence of this heated water 500 kilometers from the coast is not what surprised Baker and his colleagues at the Pacific Marine Environmental Laboratory in Seattle, for they were cruising near a seafloor spreading seafloor spreading, theory of lithospheric evolution that holds that the ocean floors are spreading outward from vast underwater ridges. First proposed in the early 1960s by the American geologist Harry H. center where hydrothermal vents are known to be active. But these observations were unprecedented because the researchers had never seen such high water temperatures extend so far above the ocean floor. This temporary region of warm water, dubbed dub 1 tr.v. dubbed, dub·bing, dubs 1. To tap lightly on the shoulder by way of conferring knighthood. 2. To honor with a new title or description. 3. a "megaplume,' also proved to be abnormally large, measuring 20 km in diameter and 700 meters thick, report the researchers in the Sept. 10 NATURE. Hydrothermal vents are known to create plumes of heated water, but oceanographers have never observed one on such a grand scale before, says Baker. The researchers reason that the megaplume resulted from "a brief but massive release of high-temperature hydrothermal hydrothermal, hydrothermic relating to the temperature effects of water, as in hot baths. fluids' over the course of a few days. Scientists had thought that hydrothermal vents flowed at slow, steady rates for periods of months or years, but it now appears that massive venting can also occur episodically ep·i·sod·ic also ep·i·sod·i·cal adj. 1. Relating to or resembling an episode. 2. Composed of a series of episodes: an episodic novel. 3. , says Baker. As for the cause of the massive release, Baker speculates that the venting may be related to episodic episodic sporadic; occurring in episodes. e. falling a paroxymal disorder described in Cavalier King Charles spaniels in which affected dogs, starting at an early age, experience episodes of extensor rigidity, possibly brought on by stress. e. rifting at the spreading center, where crustal plates pull apart, creating a gap that is filled by molten basalt basalt (bəsôlt`, băs`ôlt), fine-grained rock of volcanic origin, dark gray, dark green, brown, reddish, or black in color. Basalt is an igneous rock, i.e., one that has congealed from a molten state. . |
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