Masoud Ghandehain, a civil and environmental engineer in New York, has stated that the city’s hidden infrastructure is rapidly degrading – a scenario scientists and engineers have been predicting for a while. Ghandehain has suggested that in as little as ten years time New York’s steel and concrete foundations will be seriously undermined by the ravages of time, acid rain and salt. Normally, the steel is protected by the concrete, and a crystalline shield that forms rust on the metal, however, exposure to high amounts of salty seawater and oxygen is taking its toll. The ions in the salty water can generate an electrical charge in the metals and cause a current, similar to a battery, which then corrodes the metal.
Rising sea levels due to global warming will add to the erosion of the foundations of many coastal settlements, and in the wake of Hurricane Sandy, the decision of what to rebuild and what not, is difficult, as there will be other hurricanes.
You can find more on this story in the New Scientist journal – 10 November 2012.