New York City is sinking, in part due to the extraordinary weight of its dizzying buildings, compounding the flood threat posed by rising sea levels to the metropolis, according to new research.
The Big Apple is the city that never sleeps, but it is also the one that sinks, according to the researchers, approximately between one and two millimeters per year on average. In some areas of the city it is sinking twice as much.
The subsidence exacerbates the impact of sea level rise, which in New York is accelerating at about twice the global average as the world’s glaciers melt and seawater expands due to global warming. From 1950 to today, the water surrounding the city has risen about 22 centimeters And by the end of this century, severe storm surge flooding could be up to four times more frequent due to a combination of sea level rise and hurricanes reinforced by climate change.
“A deeply concentrated population of 8.4 million people faces varying degrees of flood hazard in New York City,” write the researchers of the study, published in the magazine Earth’s Future.
The weight of 140 million elephants
According to the authors, many other coastal cities will share the risks New York faces as the climate crisis worsens. “The combination of tectonic and anthropogenic subsidence, the rise in sea level and the increase in intensity of hurricanes represent a growing problem for coastal and coastal areas,” they say.
This trend is compounded by the size of the infrastructure built in New York. According to the researchers’ calculations, the city’s structures, including the famous Empire State Building and the Chrysler Building, weigh about 760 billion kilos, which is equivalent to about 140 million elephants.
This colossal weight pushes down a jumble of various materials found in New York soil. Many of the larger buildings sit on solid bedrock, such as shale, but there is also a mix of sands and clays, adding to the subsidence that occurs naturally along much of the US East Coast. as a reaction of the earth to the retreat of the gigantic glaciers of the last ice age.
More risk of flooding
“It’s not something to panic about right away, but it’s an ongoing process that increases the risk of flooding,” says US Geological Survey geophysicist Tom Parsons, who is leading the investigation. “The softer the ground, the greater the compression caused by the buildings. It’s not that it was a mistake to build such large buildings in New York, but you have to keep in mind that every time you build something there you push the ground down a little more.”
New York was hit in 2012 by Hurricane Sandy, which flooded parts of the subway, causing power outages and widespread damage. In 2021, Hurricane Ida flooded parts of the city and several people drowned. According to scientists, the effects of global warming aggravated these two meteorological phenomena.
New York and other coastal cities “have to start planning for this,” says Parsons. “Repeated exposure to seawater can corrode steel and destabilize buildings, something we obviously don’t want. Floods also kill people, and that’s probably the biggest concern.”
Translation by Francisco de Zárate.
2023-05-20 18:35:59
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