A recent study conducted by NASA has revealed an alarming land motion in New York City, indicating that the city is sinking underground. The study utilized space-based radar to track the changes in land motion, which is crucial for preparing communities vulnerable to flooding.
The researchers have produced a highly detailed map of vertical land motion in the metropolitan area, uncovering features that haven’t been previously noticed. While the changes in elevation are small, measuring just a few fractions of inches per year, they can have significant implications for flood prevention, especially with the continuous rise in sea levels due to climate change.
The team employed a remote sensing technique called interferometric synthetic aperture radar (InSAR) to analyze shifts in land motion from 2016 to 2023. The results revealed that human activities, such as land reclamation and the construction of landfills, have contributed to the changes in land motion. These manipulations of the Earth’s surface have caused the ground to loosen and compress beneath the infrastructure built on top of it.
Additionally, the study found that some of the land motion in New York City is a result of the last ice age approximately 24,000 years ago. The immense pressure exerted by the ice sheet during that time has caused the Earth’s mantle to continue adjusting to the changes. New York City, situated just outside the edge of the ice sheet, is now sinking back down.
On average, the researchers estimate that New York City sinks at a rate of approximately 0.06 inches per year, equivalent to the growth of a toenail in a month. Two specific areas within the borough of Queens stood out the most in the mapping data. The first is runway 13/31 at LaGuardia Airport, sinking at an estimated rate of 0.15 inches per year. Ironically, this area coincides with an $8 billion renovation aimed at mitigating flooding caused by rising waters in the Atlantic Ocean. The second area sinking rapidly is Arthur Ashe Stadium, with a rate of 0.18 inches per year. This location underwent construction for a lightweight roof during its renovation.
Although other areas of New York City are sinking at a slower rate, they still experience changes in land motion. Governor’s Island, built on 38 million square feet of rocks and dirt from early 20th-century subway excavations, has seen sinking. Similarly, sites near the ocean such as Brooklyn’s Coney Island and Queens’ Arverne by the Sea, both built on artificial fill, have also experienced land motion changes. Routes 440 and Interstate 78 near New Jersey have sinking areas as well, along with Rikers Island, attributed to its landfill expansion.
Interestingly, while some parts of the city are sinking, others are actually rising. Scientists have observed a rise of 0.06 inches per year in East Williamsburg, Brooklyn. Woodside, Queens, experienced an uplift of 0.27 inches per year between 2016 and 2019 before stabilizing. The cause of this upward land motion is not yet clear, but one theory suggests that groundwater pumping and injection wells used for treating polluted water may play a role.
The study’s findings raise concerns about the potential impact of New York City’s sinking ground, particularly in relation to flooding. The information gathered from the research will aid in better preparedness and planning to protect communities at risk. As climate change continues to exacerbate rising sea levels, it is essential to address these land motion changes to ensure the city’s resilience in the face of future challenges.
In conclusion, NASA’s study highlighting the sinking land in New York City serves as a wake-up call for the urgent need to address and adapt to the changing landscape. While the changes in elevation may seem insignificant, even a few inches can significantly increase the destructive power of flooding. By understanding and proactively responding to these challenges, New York City can continue to thrive and safeguard its population against the escalating dangers of climate change.
