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Skerryvore (from the Gaelic ''An Sgeir Mhòr'' meaning "The Great Skerry") is a remote reef that lies off the west coast of Scotland, 12 miles (19 kilometres) south-west of the island of Tiree. Skerryvore is best known as the name given to the lighthouse on the skerry, built with some difficulty between 1838 and 1844 by Alan Stevenson.〔("Skerryvore Lighthouse" ) Northern Lighthouse Board.〕 At a height of 156 feet (48 m) it is the tallest lighthouse in Scotland.〔("Historical Information" ) Northern Lighthouse Board. Retrieved 17 January 2008.〕 The shore station was at Hynish on Tiree (which now houses the Skerryvore Lighthouse Museum); operations were later transferred to Erraid, west of Mull. The remoteness of the location led to the keepers receiving additional payments in kind.〔Munro (1979) pp. 181–2.〕 The light shone without a break from 1844 until a fire in 1954 shut down operations for five years. The lighthouse was automated in 1994.〔〔 ==Geology== In pre-historic times the rocks that now form Skerryvore were covered by the ice sheets that spread from Scotland out into the Atlantic Ocean beyond the Outer Hebrides. After the last retreat of the ice around 20,000 years ago, sea levels were up to 400 feet (122 m) lower than at present.〔Pennington, W. (1969) ''History of British Vegetation''.〕 Although the isostatic rise of land makes estimating post-glacial coastlines a complex task, circa 14,000 BP it is likely that the reef was at the south western end of a large island consisting of the modern islands of Tiree and Coll and the surrounding land.〔Murray (1973) p. 69.〕 Steadily rising sea levels would then have slowly isolated and finally all but submerged the shoals of Skerryvore, a barrier of innumerable metamorphic remnants that stretch for 8 miles (13 kilometres) lying in a south-westerly direction. A detailed survey undertaken in 1834 listed more than 130 main rocks including ''Am Bonn Sligheach'' (Boinshley) ((スコットランド・ゲール語:The Deceitful Bottom)) and ''Am Bogha Ruadh'' ((スコットランド・ゲール語:The Red Submerged Rock)).〔Bathhurst (2000) p. 150.〕 The rocks have been worn smooth by the action of the waves and are constantly affected by spray. Alan Stevenson wrote: "The effect of the ''jet d'eau'' was at times extremely beautiful, the water being so broken as to form a snow-white and opaque pillar, surrounded by a fine vapour in which, during sunshine, beautiful rainbows were observed ".〔Stevenson, Alan (1848) ''Account of the Skerryvore Lighthouse, with notes on Lighthouse Illumination''. Quoted in Nicholson (1995)〕 It is an isolated outpost of the Inner Hebrides archipelago composed of Lewisian gneiss, formed in the Precambrian eon, these rocks being amongst the most ancient rocks in Europe.〔Nicholson (1995) p. 105.〕〔("Geopark" ) Knockan Crag National Nature Reserve. Retrieved 26 January 2008.〕 A further hazard to shipping is a magnetic anomaly in the area.〔Baird, Bob (1995) ''Shipwrecks of the West of Scotland''. Glasgow. Nekton. p. 188.〕 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「Skerryvore」の詳細全文を読む スポンサード リンク
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