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A brinicle (brine icicle, also known as ice stalactite) forms beneath sea ice when a flow of extremely cold, saline water is introduced to an area of ocean water, being the undersea equivalent of a hollow stalactite or icicle. Known since the 1960s, the generally accepted model of their formation was proposed by the US oceanographer Seelye Martin in 1974. The formation of a brinicle was first filmed in 2011 by producer Kathryn Jeffs and cameramen Hugh Miller and Doug Anderson for the BBC series ''Frozen Planet''. ==Structure== At the time of its creation, a brinicle resembles a pipe of ice reaching down from the underside of a layer of sea ice. Inside the pipe is the supercold, supersaline water being produced by the growth of the sea ice above, accumulated through brine channels. At first, a brinicle is very fragile; its walls are thin and it is largely the constant flow of colder brine that sustains its growth and hinders its melt that would be caused by the contact with the less cold surrounding water. However, as ice accumulates and becomes thicker, the brinicle becomes more stable. A brinicle can, under the proper conditions, reach down to the seafloor. To do so, the flow of supercold brine from the pack ice overhead must continue, the surrounding water must be significantly less saline than the brine, the water cannot be very deep, the overhead sea ice pack must be still, and currents in the area must be minimal or still. If the surrounding water is too saline, its freezing point will be too low to create a significant amount of ice around the brine plume. If the water is too deep, the brinicle is likely to break free under its own weight before reaching the seafloor. If the icepack is mobile or currents too strong, strain will break the brinicle. Under the right conditions, including favorable ocean floor topography, a brine pool may be created. However, unlike brine pools created by cold seeps, brinicle brine pools are likely to be very transient as the brine supply will eventually cease. On reaching the seafloor, it will continue to accumulate ice as surrounding water freezes. The brine will travel along the seafloor in a down-slope direction until it reaches the lowest possible point, where it will pool. Any bottom-dwelling sea creatures, such as starfish or sea urchins can be caught in this expanding web of ice and be trapped, ultimately freezing to death. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Brinicle」の詳細全文を読む スポンサード リンク
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