New York City: A City in Constant Sinking
A recent study carried out by Earth’s Future magazine has revealed that New York City is sinking year after year, between one and two millimeters, due to the great weight of its skyscrapers. The rate of subsidence doubles in some areas of the city, such as Lower Manhattan. According to the study, the subsidence of the city is aggravating the impact of sea level rise, which is accelerating approximately twice as fast as the world average. This places the Big Apple as the third city in the world with the risk of suffering more coastal flooding.
Rising Sea Levels and Storm-Induced Flooding
Since 1950, the water level around New York has risen up to 9 inches, or the equivalent of a subsidence of 22 centimeters. This means that storm-induced flooding could be up to four times more frequent now. The subsidence of the city is contributing to the increasing risk of flooding, which affects the concentrated population of 8.4 million people who live in New York City.
Soil Quality and Building Weight
The study notes that, in some cases, the heaviest and largest buildings were built on solid bedrock, such as the shale. However, there are parts of the city where it was built on sand sediments and clay deposits. In these areas, the weight of the buildings pushes these components with greater force, increasing the subsidence of the city. “The more softer the ground, the greater the compression of the buildings. It was not a mistake to build such large buildings in New York, but we must keep in mind that every time you build something there, you push the ground a little more (…) The cumulative pressure applied to the ground by large buildings contributes to subsidence,” according to the researchers.
The Weight of New York City’s Buildings
The researchers calculated that the city’s buildings, which include the famous Empire State Building and the Chrysler Building, weigh a total of 1.68 trillion pounds. This is equivalent to approximately 760 billion kilos, which represents the weight of 140 million elephants. The excess weight is contributing to the subsidence of the city, worsening the risk of flooding.
By 2050, sea level rise is expected to be 200 to 600 millimeters globally. As the population grows, this problem may worsen. Although it is not something to panic about immediately, the ongoing process of subsidence increases the risk of flooding in New York City. The city needs to address this issue and take action to avoid potential disasters in the future.