Black ice

Black ice is a thin coating of ice on a surface, often a roadway. While not truly black, it is transparent, allowing the usually-black asphalt/Macadam roadway to be seen through it, hence the term.

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It is usually deposited by freezing rain, mist, or fog. Because it contains relatively little entrained air in the form of bubbles, black ice is transparent and thus very difficult to see (as compared to snow, frozen slush, rime ice, or other typical roadway forms of ice). In addition, it often has a matte appearance rather than the expected gloss; and often is interleaved with wet pavement, which is identical in appearance. For this reason it is especially hazardous when driving or walking.

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Black ice may form even when the ambient temperature is several degrees above the NTP freezing point of water. This occurs typically, and treacherously, when terrain contours and/or prevailing wind cause a local steep differential of atmospheric pressure and/or temperature or when the atmosphere has warmed up after a prolonged cold spell that leaves the temperature of the ground (and roadway!) well below the freezing point.

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Black ice also refers to the slick layer that forms on roadways from a light rain after a period without any precipitation. The water mixes with the road dust and oil but doesn't wash away. This leaves the road surface as slick as ice, slicker than just being wet with water. This type of road hazard can occur any time of year, but especially in mostly dry summer months.

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In either case, while definitely a real phenomenon, "black ice" may be cited as the cause of a car crash when, in fact, the real root cause may have been excessive speed, inattention, or some other fault on the part of the driver.

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Black Ice can also be a deadly danger for fishing trawlers especially in the North Sea in winter. The crews of these vessels used axes to try to chip away the ice, often with increasing desperation as it could form faster than it could be cleared leading ultimately to capsize if the icing persisted.

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Ice: Ice is the solid form of water. The phase transition occurs when liquid water is cooled below 0 ?C (273.15 K, 32 ?F) at standard atmospheric pressure....

Black: :This article is about the color black; for other uses, see Black (disambiguation)....

Asphalt: :The term asphalt is often used as an abbreviation for asphalt concrete....

Black ice related Images and Photos (experimental)

Black Ice Skates	AC/DC - Black Ice	AC/DC Black Ice Canvas Print	AC/DC Black Ice Framed Mirror Art
AC/DC Black Ice Fabric Poster Wall Hanging	Black	Ice-T	Ice T
Black Cat	Black Ops	Black Eye (1974)	Black Fury