According to a new study, Not the entire city NY is equalAnd some parts of the region, such as major highways and the US Open tennis courts, are sinking faster than others, increasing the risk of flooding as sea levels rise.
The runway at LaGuardia Airport, Arthur Ashe Stadium, Interstate 78 — which includes the Holland Tunnel — and Highway 440, which connects New Jersey and Staten Island, are sinking more than 2 millimeters a year. According to a study published Wednesday Scientific advancesThey are sinking faster than New York City’s average of 1.6 millimeters.
“If you’re an average citizen in a coastal city, I think it’s important for you to understand what the vertical ground movement component does and how it can change flood vulnerability, even from neighborhood to neighborhood,” he said. Bret BujangaLead author of the study and a coastal scientist at NASA’s Jet Propulsion Laboratory.
Comparatively, the millimeter drop in New York City doesn’t seem like a big deal. But that will make flooding worse with rising sea levels. Over the past 20 years, sea levels in Manhattan have risen 4.4 millimeters per year, partly due to land subsidence, according to the study. This can 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 sea level rise.
“Rising sea levels and shrinking landmasses will cause more damage,” Busanga said. “It’s kind of an addition to the background conditions that these storms are operating in. There’s still water to stir.
Bujanga and his colleagues used A new technique that uses satellite data to obtain high-resolution measurements and compare environments. The survey leverages GPS data from ground-based instruments or aircraft that can collect high-resolution data, but on a point-by-point basis.
“We highlighted the differences in the region in a very unprecedented way, and some points may sink faster than others, and some places may flood more,” Pusanga explained. “It’s the same in any city.”
New York is one of many coastal cities experiencing land subsidence. Other research shows, for example, that Norfolk and Virginia coasts sink by an average of more than 3.5 millimeters per year. Some areas around New Orleans have experienced 40 millimeters of fall per year.
Land can sink for many reasons. In New York, much of the fall was caused by retreating glaciers from the last Ice Age., when ice sheets weigh down the land and submerge the crust beneath areas such as the northeastern United States. However, New York City was on the periphery of the submergence zone and was swelling upward. As the ice sheets began to retreat, the land began to slowly level, and the escarpments began to rise, while the hummocks began to sink.
Think of the change as pressing your finger into a balloon (acting as an icicle) and then lifting it (retracting 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, LaGuardia sinkholes, Arthur Ashe Stadium and some highways were formerly landfills. According to Pusanga, those spaces “will compress much faster than those built on more solid ground.”
Arthur Ashe Stadium has been renovated With a special lightweight roof to reduce falls.
The study also found some unexpected areas of land elevation. For example, In Brooklyn, Newtown Creek in East Williamsburg rose 2 millimeters per year. The study indicates that the area has a major engineering project to recover and treat contaminated groundwater from the creek’s aquifer, which will cause the land to rise. But rising landmasses can disrupt infrastructure.
Tom ParsonsA USGS geophysicist who was not involved in the study said the authors were impressed with the resolution of the subsidence and uplift data they obtained.
Their results are consistent with previous results by Parsons and his colleagues: infrastructure built on artificial landforms along or near coastlines is sinking at a faster rate.
The study confirms the utility of satellite data “in helping to manage many issues such as where large buildings are constructed in large cities, the use of artificial fill and the need for protective measures against future flooding,” Parsons said.
Steven D’Hond, a professor of oceanography at the University of Rhode Island who was not involved in the new research, said settlement of built-up areas on landfills could be exacerbated by the weight of buildings and runways. But infrastructure subsidence from this extra weight usually stops a few years after construction, so it’s not primarily a contributing factor to land subsidence.
According to Puszanga, he and his colleagues plan to use their new method to obtain data on vertical displacement across North America, which could help assess a community’s flood risk and urban planning.
“Every city in the world could benefit from such a refined analysis of vertical ground motion across the city,” said D’Hond.
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