Satellite data shows New York city is sinking

Satellite data shows that the metropolis of New York is sinking between 1 to 2 millimeters on average each year.

Some of this is natural, such as residual effects of land settling after the last ice age, and some is caused by people withdrawing groundwater. But the immense weight of the Big Apple’s buildings is also playing a role, according to a study published this month in the journal Earth’s Future.

The report stated that with the land slowly sinking, the threats already posed by rising sea levels and intense storms just get worse. And New York City isn’t the only coastal urban area that’s sinking.

“Sea level rise is eventually going to pose inundation challenges in New York and globally,” Tom Parsons, a co-author of the study and geophysicist at the U.S. Geological Survey, told Live Science.

The city’s 1,084,954 buildings weigh over 76 trillion kilograms, researchers estimated – almost double the weight of all of humanity combined.

To predict the amount of sinking due to this tremendous load, the team modeled the buildings and the various types of land beneath them. They found that depending on the underlying types of soil, bedrock and other factors, buildings have the potential to sink as much as 600 millimeters, or almost two feet, the Smithsonian reported.

“It’s not something to panic about immediately, but there’s this ongoing process that increases the risk of inundation from flooding,” Parsons said.

Human-caused global warming also compounds the risk of flooding, both by melting ice sheets and glaciers and by warming seawater, causing it to expand.

Globally, sea levels have risen up to 70 cm since 1880, but in New York City, the water has climbed around that much in the last 73 years alone. About three decades from now, sea levels could be an estimated another 70 cm higher around New York City.