New York’s public housing is sinking — literally

Grist: Like many coastal cities around the world, New York City is sinking. On a year-to-year basis, the rate of its descent into the Earth is practically imperceptible, but over time those millimeters add up: Today, the city is 9 inches lower than it was in 1950 — a number that has serious implications for waterfront neighborhoods that are having to reckon with increasingly extreme storms.

Sea level rise isn’t the only culprit behind the sink. The city is also being literally weighed down by its massive skyscrapers. The influence of those trillions of pounds of steel and concrete on the city’s rate of sinking is the subject of a paper, published earlier this month in the scientific journal Earth’s Future.

New York’s skyscraper-driven sink is due to a process known as subsidence, or the gradual caving in of an area of land. The phenomenon can result from a number of factors including sediment deposition or resource extraction, but in New York City it comes down to the sheer weight of the built environment.

Unsurprisingly, that weight (or “urban load,” as the authors call it) is greatest in Manhattan’s midtown and its downtown waterfront, the sites of many of the towering buildings that make up the city’s iconic skyline. But the paper also identifies subsidence-prone areas in certain parts of south Brooklyn, the Bronx, and Queens where many of the city’s sprawling public housing developments are located.

Some boroughs are more equipped to deal with the sinking threat than others. Read more>>