Sinking the Big Apple - 19th June 2023

New York City's gradually sinking into the ocean, a shocking revelation from new geological research utilising satellite data. The study, published in Advancing Earth and Space Science, highlights the city's subsidence, attributed to the shifting soil caused by the weight of its numerous skyscrapers. While subsidence typically arises from mineral or oil extraction, particularly fracking, in this case, the colossal edifices are the main culprit, leading to an occurrence known as settlement.

For over two centuries, New York City has been the most populous city in the United States. Following a period of rapid expansion in the late 19th century, city planners opted for vertical growth rather than horizontal expansion. Since the construction of the city's first skyscraper, Tower Building, in 1889, more than 6,000 high-rise buildings have been erected, including an astonishing 274 skyscrapers towering over 150 metres. The sheer mass of this concrete jungle amounts to a staggering 764 billion kilograms.

Soil composition's a further contributing factor. A significant portion of New York City's built on clay-rich soil and artificial fill, speculated by scientists to be "especially prone to significant building settlement". Clay exhibited the greatest potential for subsidence, ranging from -75 to -600 millimetres.

Presently, the approximately 8.4 million denizens of New York City are at risk of flooding and future natural disasters. While a few millimetres of subsidence may not appear grave, due to the weight of their buildings and the composition of the soil, certain boroughs are sinking at even faster rates. Combined with the rising global sea levels, the city that never sleeps may eventually bear a resemblance to the Italian city of Venice.

New York City's not the sole urban landscape under threat, as many cities struggle with subsidence and settlement. Jakarta, home to 10.5 million people, is sinking at a rate of 4.9 centimetres annually due to excessive groundwater extraction. Consequently, the Indonesian government's constructing a new capital called Nusantara on the island of Borneo.

With projections indicating that 70 percent of the world's population will reside in cities by 2050, it's imperative that we carefully consider where and how we construct our urban centres.