New York City has a weight problem: the massive buildings squishing Manhattan. "The Weight of New York City: Possible Contributions to Subsidence From Anthropogenic Sources," published in the Earth's Future journal, describes the "contribution to subsidence from the cumulative mass and downward pressure exerted by the built environment of the city." The problem: "accelerating inundation risk from sea level rise."
Oliver Milman summarizes at The Guardian:
This enormous heft is pushing down on a jumble of different materials found in New York City's ground. While many of the largest buildings are placed upon solid bedrock, such as schist, there is a mixture of other sands and clays that have been build over, adding to a sinking effect that is naturally occurring anyway along much of the US east coast as the land reacts to the retreat of huge glaciers following the end of the last ice age.
"It's not something to panic about immediately but there's this ongoing process that increases the risk of inundation from flooding," said Tom Parsons, a geophysicist at the US Geological Survey, who led the new research.
"The softer the soil, the more compression there is from the buildings. It wasn't a mistake to build such large buildings in New York but we've just got to keep in mind every time you build something there you push down the ground a little bit more."
Mumbai and Jakarta reading this study with wan, fixed smiles.