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The Jumpinpin channel also known as The Pin lies between North Stradbroke Island and South Stradbroke Island. It has a fast moving tidal deep water Channel not appropriate for swimming but is popular with beach anglers. The word Jumpinpin is of Aboriginal origin. It is derived from the word 'oumpinin' which refers to the sweetened roots of the wynnum (breadfruit) tree which was feasted on when tribes met in the area. The bar area is shallow for a kilometre or so offshore so current local knowledge is required to safely transit the bar. The area around the Pin is constantly changing with sand being deposited in one place after being moved by currents from another area. Just recently the mouth of Swan Bay was moved several hundred metres seaward creating an entirely new boating area. The area is not really suitable for swimming as big tides and fast currents are the norm. Inland from the bar the Pin area consists of mangroves and mud banks, constantly being built up and then being washed away. In recent years Rat Island, The Mud Clump and Squire Island have disappeared. ==Formation== A channel in the general area of Jumpinpin may have formed and silted up several times over recent millennia, however, the most recent formation of the channel is generally blamed on two events. The first of these was the wreck of the ''Cambus Wallace'', a 75 m steel barque of 1534 tonnes built in 1894 at Port Glasgow. In the early morning of 3 September 1894, the ''Cambus Wallace'' ran aground in heavy seas near what was then a narrow stretch of Stradbroke Island called Tuleen. Most of the crew managed to swim to shore, but six men drowned and were buried on the beach. The ship broke up where she struck and most of the cargo was washed ashore and plundered by local residents. During the subsequent cleanup, explosives from the cargo were piled up and deliberately detonated on the beach leaving large craters.〔 The explosion is credited with severely damaging the beach and weakening the loosely vegetated sand dunes. Following gradual erosion of the seaward side of the island over the next two years, the second event to ultimately generate the channel at Jumpinpin was the arrival of a cyclone in 1896. Thomas Welsby, writing in 1921, noted, "Within two years (1896) the southeast gales threw again their power and fury on the very spot whereat the ''Cambus Wallace'' had come to grief, drove the rollers and breakers against the sandy hillside until it conquered and made passage into Swan Bay."〔Welsby, T. (26 March 1921). "Stradbroke Island". Brisbane ''Courier Mail''. Rpt. in Thomson, A. K., ed. ''The Collected Works of Thomas Welsby''. Vol. 1. Brisbane: Jacaranda Press, 1967.〕 Once the entrance was established, the heavy seas and strong tidal currents were sufficient to enlarge the channel from 20 feet to more than a mile and a quarter by 1898.〔 Changes to tidal inundation in the area around the mouth of the Logan River were dramatic.〔 Erosion occurred on farm land and some farmers resorted to building canals. The oyster industry in the area was also affected by what was claimed to be changes in the water density interfering with the ability of the oysters to settle on the seafloor.〔 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「Jumpinpin Channel」の詳細全文を読む スポンサード リンク
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