It’s a scary prospect: New York City, Long Island, and other coastal regions are slowly sinking. It may only be a fraction of an inch each year, but that’s enough to impact buildings and the people in them significantly. And as sea levels rise, it could put the entire city in jeopardy.
The culprit is subsidence, a natural process that causes the land to drop in various places worldwide. While this is typically attributed to deglaciation, it’s now been shown that the weight of buildings can also be factored in. And that’s causing cities to sink faster than expected.
A team of scientists from the University of Rhode Island Graduate School of Oceanography has analyzed satellite data from cities across the globe and found that New York City, among others, is sinking at a rate of 1 to 2 mm per year. That’s more than twice the average global sea level rise and puts many neighborhoods at risk for flooding.
To better understand what was causing the sinking, researchers used a combination of computer modeling and GPS measurements. They compared the results with satellite data from the past decade and identified areas where the sinking was most significant. They then accounted for factors other than urban weight to see how much of the subsidence was caused by buildings. Their calculations showed that the city’s buildings contribute to the overall sinking about a third of the time, with the rest due to other processes.
In addition to putting homes and businesses at risk of floods, the city’s subsidence also affects critical infrastructure like roads and railways. This is because these infrastructure assets are often built on low ground. If the city continues to sink, they may need to be moved or replaced.
Although the threat is still far off, it’s essential to be aware of the growing problem. Especially since many of us live in coastal areas and work in high-rise offices, it’s vital to consider building codes and other environmental standards that will help prevent these types of disasters in the future.
