![]() “These individual pock-marks can be anywhere from 10-18m in diameter and up to 6m deep in places. “At the time of the survey, dredging vessels were not active in this area, so this uneven topography is a result of long-term dredging, suggesting that the uneven topography persists through time and does not even out back to a smooth surface. “However, our new survey demonstrates the lough bed is now highly uneven, with clear pock-marks and scars evident resulting from the suction-dredging. ![]() “From admiralty charts and depths - collected back in 1851 - the lough bed showed a smooth, slowly-sloping bed,” he said. ![]() “That’s a 16-17m (52.5ft-56ft) lowering of the lough bed as a result of extraction.”ĭr Hackney compared the current status of the lough with data from charts created more than 170 years ago, before any sand was dredged. “However, years of extraction has removed sediments from the bed such that depths are now, in places, 21m (69ft) deep. “The lough bed used to be around four to five metres (13ft - 16.4ft) deep in that part of the lough,” Dr Hackney told The Detail. His work found that sand dredging alone has created scars of up to 56 feet deep (17 metres) in places.ĭredging has also caused several deep ‘pock marks’ of up to 19.6ft (6m) deep. The survey looked at an area of half a square kilometre where around two million tonnes of sand have been dredged in recent years. Photo courtesy of Newcastle Universityĭr Hackney, an academic at Newcastle University, carried out a survey of the depth of the bed in August to measure the impact of industrial sand extraction. Dr Chris Hackney is a sand-mining expert. ![]()
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