Study warns that New York is sinking: the areas of most concern

According to a new study, And not the entire territory of the city New York It is evenly levelSome areas of the region, such as major highways and the U.S. Open tennis court, are sinking more quickly than others, increasing the risk of flooding as sea levels rise.

According to researchers, the runway at LaGuardia Airport, Arthur Ashe Stadium, Interstate 78 — which includes the Holland Tunnel — and Interstate 440, which connects New Jersey to Staten Island, is sinking more than 2 millimeters per year. According to the study published on Wednesday Advancement of sciencesinking faster than the New York City average of 1.6 mm per year.

“If you’re an average citizen in a coastal city, I think it’s important to understand what the vertical ground motion component does and how it can change flood vulnerability, even from neighborhood to neighborhood,” he said. Brett Bozangalead author of the study and a coastal scientist at NASA’s Jet Propulsion Laboratory.

Relatively speaking, a millimeter of subsidence in New York City may not seem like a big deal, But they can worsen flooding as sea levels rise. Over the past 20 years, sea levels have risen 4.4 millimeters annually in Manhattan, partly due to land subsidence, according to the study. This could have serious consequences when extreme weather events occur: one study estimated that about $8 billion in damage caused by Superstorm Sandy in 2012 could be linked to rising sea levels.

“Rising sea levels and shrinking land surfaces could cause more damage,” Buzanga said. “It kind of adds to the background condition that these storms are working on. There’s more water to move around.”

Buzzanga and colleagues used A new technology that uses satellite data to obtain high-precision measurements and compare neighborhoods. The study improves on GPS data from ground devices or aircraft that can also collect high-resolution, but point-by-point, data.

“We have highlighted in unprecedented detail the differences across the region and that some areas may sink faster than others, potentially causing more flooding in some areas,” Bouzanga explained. “This would be the same in any city.”

New York is one of many coastal cities where land subsidence is observed. Other research has shown that the cities of Norfolk and Virginia Beach, for example, are sinking on average more than 3.5 millimeters per year. Some areas around New Orleans saw subsidence at a rate of 40 mm per year.

Land can sink for several reasons. In New York, most of the decline is due to retreating glaciers from the last ice ageWhen ice sheets weighed down the Earth and caused the crust to expand and sink beneath areas such as the northeastern United States. However, New York City was on the margins of the sinking zone and swelling upward. As the ice sheets began to retreat, the land began to slowly level out, and the fallen areas began to rise while the bulge areas began to sink.

Think of the change as pressing your finger (like an icicle) on a balloon and then lifting it (pulling the icicle).

But human activities can add additional pressure to our Earth, causing it to sink or rise beyond these deep natural processes. According to the study, the LaGuardia Pits, Arthur Ashe Stadium and some highways were former landfills. According to Busanga, these places “will compress much faster than anything built on firmer ground.”

Arthur Ashe Stadium has been renovated With a special lightweight roof to reduce subsidence.

The study also discovered some unexpected areas where the terrain was rising. For example, In Brooklyn, Newtown Creek in East Williamsburg rose by about 2 mm per year. The study indicates that the area has a huge engineering project to recover and treat polluted groundwater from the Al-Khor aquifer, which could lead to land elevation. But rising terrain can also destabilize infrastructure.

Tom ParsonsA USGS geophysicist who was not involved in the study said he was impressed by the subsidence and elevation data obtained by the authors.

Their conclusions also match previous findings by Parsons and colleagues: Infrastructure built on artificial landfills on or near the coast appears to be sinking at a faster rate.

Parsons said this study underscores the utility of satellite data “in helping major cities manage multiple issues, such as where to build large buildings, to use artificial fill, and where protection measures are needed against future flooding.”

Steven DehundtSettlement of places built on landfills could be exacerbated by the weight of buildings and runways, added the University of Rhode Island oceanography professor who was not involved in the new research. But subsidence caused by this additional weight of infrastructure usually stops after a few years of construction, so it is not a fundamental contributing factor to land subsidence.

According to Busanga, he and his colleagues plan to use their new algorithm to obtain data on vertical displacement across North America, which could help with community flood risk assessment and city planning.

“Every city in the world would benefit from such a precise analysis of vertical ground motion at the city level,” Dhondt said.

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