Land in New York City is sinking and rising at varying rates, according to a new study conducted by researchers from NASA’s Jet Propulsion Laboratory (JPL) in Southern California and Rutgers University in New Jersey. The study, published in Science Advances, utilized space-based radar to analyze vertical land motion in the metropolitan area from 2016 to 2023.
The findings reveal that the elevation changes, although small at fractions of inches per year, can have a significant impact on flood risk associated with sea level rise. Factors influencing the land motion include human land-use practices, such as land reclamation and construction of landfills, as well as natural processes dating back to the ice age.
The study indicated that the New York City metropolitan area is subsiding on average by about 0.06 inches per year. However, the researchers were able to identify specific neighborhoods and landmarks that are subsiding at a higher rate. For example, LaGuardia Airport’s runway 13/31 is subsiding at a rate of about 0.15 inches per year, while Arthur Ashe Stadium is sinking at a rate of about 0.18 inches per year. These findings are particularly significant for flood mapping and planning purposes, as sea levels continue to rise globally.
In addition to subsidence, the researchers also discovered previously unidentified areas of uplift. East Williamsburg, Brooklyn, was found to be rising by about 0.06 inches per year, while Woodside, Queens, experienced a rise of 0.27 inches per year from 2016 to 2019 before stabilizing. Further investigation is needed to determine the causes of this uplift, which may be related to groundwater pumping and injection wells used for treating polluted water.
Cities like New York that are investing in coastal defenses and infrastructure to combat sea level rise can benefit from high-resolution estimates of land motion. The detailed map produced by the study provides valuable information for future monitoring and planning efforts.
The researchers plan to continue monitoring surface displacement across North America through the JPL-led OPERA project, which will leverage data from the upcoming NISAR mission set to launch in 2024. This information will help scientists better understand vertical land motion and its implications for natural hazards.
As Earth’s climate continues to change, understanding and monitoring land motion is critical for managing flood risk and ensuring the resilience of coastal cities like New York.