“The Sinking City: New York’s Building Subsidence Threatens Future Flood Risks”

News JVTech The sinking city: New York is threatened by building subsidence

New York: the sinking city

A new study reveals that New York City is sinking under the collective weight of all its buildings. This gradual process could spell trouble for a city whose sea level is rising more than twice as fast as the global average, and is expected to rise 8 to 30 inches by 2050.

Additionally, scientists predict more frequent and extreme precipitation events, such as northeast storms and hurricanes, due to the man-made climate crisis.

We are still far from seeing the ocean overflow. But we have already seen several major flood events in New York, such as Sandy and Ida, where heavy rainfall has caused flooding in the city, and some effects of urbanization have allowed water to enter.

Tom Parsons, geophysicist and lead author of the study.

The article, published in the journal Earth’s Future, aims to show how high-rise buildings in coastal, riverine or lakeside areas could contribute to future flood risksand why steps should be taken to mitigate potentially harmful impacts.

The researchers calculated the mass of the 1,084,954 existing buildings in New York City’s five boroughs at the time, concluding that they weighed around 1.68 trillion pounds (762 billion kilograms) – the equivalent of approximately 1.9 million fully loaded Boeing 747-400s.

The research team then used simulations to calculate the effects of this weight on the ground, comparing it with satellite data showing actual surface geology.

Subsidence is the technical term for the sinking or settling of the earth’s surface due to natural or man-made causes.. A September 2022 study found that 44 of the 48 most populated coastal cities have areas that are sinking faster than sea level rise. The innovative approach of this latest study is to specifically consider the weight of New York City buildings and their contribution to the subsidence of the ground beneath them.

The reasons for this phenomenon

However, not all depressions are due to buildings. “We can see a correlation when building is done on very soft ground and artificial fill,” Parsons said. “In other places we see subsidence that is difficult to explain. There are many possible causes, such as post-glacial release that occurred after the last ice age, or groundwater pumping.”
Some areas of Lower Manhattan, Brooklyn and Queens are among those sinking at an above-average rate, according to the study.

Subsidence may pose an even earlier threat of flooding than sea level rise, the research suggests, and not just in New York.

It’s a global problem. My co-authors from the University of Rhode Island have looked at 99 cities around the world, not just coastal but also inland, and the vast majority of them are experiencing subsidence issues.

Décalre Parsons, citing the case of Jakarta, which is sinking so rapidly that the Indonesian government plans to build a new capital elsewhere.

We know that sea levels are rising and coastlines are changing, and it is essential to understand the impact of human activities, such as greenhouse gas emissions, on our warming world.

said Sophie Coulson, geophysicist and postdoctoral researcher at Los Alamos National Laboratory, who was not involved in the study.

According to her, the authors use a clever combination of computer modelling, satellite measurements and GPS data to estimate short- and long-term sinking rates in different areas of the city and identify areas most at risk.

New York is one of the most densely populated coastal areas in the world, with much of its critical infrastructure built in low-lying coastal areas.
Understanding how and why the landscape is changing, and identifying the areas most vulnerable to flooding, is key to effectively preparing to mitigate future sea level rise.