New York City, on the east coast of the United States, is sinking below sea level by 1 to 2 millimeters per year, according to a new study메이저사이트. Skyscrapers weighing as much as 70,000 Eiffel Towers and 140 million elephants have been blamed for the pressure on the ground and rising sea levels due to climate change.

New York City, home to more than 8 million people, is sinking every year, according to a paper by U.S. Geological Survey (USGS) geologist Tom Parsons and colleagues in the May issue of the environmental journal Earth Future, titled “The Weight of New York City: The Likelihood of Subsidence from Anthropogenic Causes,” which points to the city’s nearly 1 million skyscrapers as a contributing factor.

Of the city’s five boroughs, Manhattan, Queens, Brooklyn, and Staten Island, with the exception of the Bronx, are all islands bordering the Atlantic Ocean. Lower Manhattan, in the skyscraper-dense Wall Street financial district, is subsiding at twice the rate, the team found. Queens and Brooklyn are also losing ground, they added.

The total weight of all 1 million skyscrapers, the team estimated, is about 770 million tons, equivalent to the weight of 70,000 Eiffel Towers and 140 million elephants. New York’s major skyscrapers, including the Empire State Building, are built on solid bedrock, but some are constructed on a mixture of sand and clay, which increases the rate of subsidence, the researchers said.

Rising sea levels due to climate change are also having an adverse effect. Since 1950, sea levels around New York City have risen about 22 centimeters, which, combined with hurricanes, could make major flooding more than four times as frequent in the future, the team warned. “We are seeing subsidence not only in New York, but in coastal cities across the U.S. and around the world,” the researchers said, adding that the world needs to prepare for the risk of flooding.