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United States Geological Survey scientists warn New York City, and Lower Manhattan in particular, is sinking under the weight of all of its building.
A new study published in the scientific journal Earth’s Future revealed this finding after the researchers modeled the geology beneath New York City and compared it to satellite data.
Not that there is much anyone can do about it. In fact, the problem is only going to continue to get worse.
It’s part of a common natural phenomenon called subsidence, a press release covering the study explains.
Subsidence is the “gradual settling or sudden sinking of Earth’s surface occurs when soft sediments shift, or loads bearing down on the ground push it deeper still.”
“Increased urbanization, including the draining and pumping of groundwater, could only add to New York’s subsidence problem,” the report reads.
According to the study, New York City is sinking at a rate of 1 to 2 millimeters per year.
A few millimeters might not sound like much, but some parts of the city are subsiding much faster, on par with the fastest observed rates at which tectonic plates rebound when glaciers melt.
The deformation could spell trouble for the low-lying city home to more than 8 million people, so the findings should encourage further efforts to develop mitigation strategies to counter growing flood risk and rising sea levels – though perhaps building gigantic sea walls to fortify the city aren’t the right answer.
“The point of the paper is to raise awareness that every additional high-rise building constructed at coastal, river, or lakefront settings could contribute to future flood risk,” wrote geologist Tom Parsons of the United States Geological Survey and his colleagues at the University of Rhode Island.
The study also calculates that the cumulative mass of the more than one million buildings in New York City weigh 1.68 trillion pounds (or 850,000,000 tons).
That number does not include roads, sidewalks, bridges, railways, and other paved areas of the city, which also carry considerable weight. Nor does it include the millions of people and all of their stuff.
Lower Manhattan is only one to two meters above current sea levels.
“New York is emblematic of growing coastal cities all over the world that are observed to be subsiding, meaning there is a shared global challenge of mitigation against a growing inundation hazard,” wrote the researchers.