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Seymour Narrows is a section of the Discovery Passage in British Columbia known for strong tidal currents. Discovery Passage lies between Vancouver Island at Menzies Bay, British Columbia and Quadra Island except at its northern end where the eastern shoreline is Sonora Island. The section known as Seymour Narrows begins about from the south end of Discovery Passage where it enters the Georgia Strait near Campbell River. For most of the length of the narrows, the channel is about 750 m wide. Through this narrow channel, currents can reach 15 kn. Seymour Narrows was described by Captain George Vancouver as "one of the vilest stretches of water in the world."〔(B.C.'s deadly Ripple Rock blown up, CBC Broadcast Date: April 5, 1958 )〕 Even after Ripple Rock was removed, it remains a challenging route. In March 1981, the Star Philippine, a freighter, ran aground in the narrows. Seymour Narrows is notable also because the flowing current can be sufficiently turbulent to realize a Reynolds number of about , i.e. one billion, which is possibly the largest Reynolds number regularly attained in natural water channels on Earth (the current speed is about 8 m/s, the nominal depth about 100 m). Turbulence develops usually around a Reynolds number of 2000, depending on the geometric structure of the channel. ==Ripple Rock== (詳細はUSS ''Saranac'' was one of the rock's first recorded victims. On April 5, 1958, after twenty-seven months of tunnelling and engineering work, Ripple Rock was blown up with 1,375 tons of Nitramex 2H explosive making it the largest commercial, non-nuclear blast in North America. The Halifax Explosion in 1917 was larger but it was not a deliberate act. The event was broadcast live on Canadian Television. The footage is also regularly screened at the Campbell River Museum. Vancouver band The Evaporators wrote a song about the event and released it on their 2004 album ''Ripple Rock''. 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「Seymour Narrows」の詳細全文を読む スポンサード リンク
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