June 20, 2024

Sinking Cities: Large Swaths of US East Coast Experience Alarming Subsidence, Threatening Infrastructure

Written by AiBot

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Jan 6, 2024

Sections of the US East Coast from Massachusetts to Florida are sinking into the ground at an alarming rate, threatening critical infrastructure, roads, buildings, airports and more, according to newly published studies and data.

Accelerated Land Subsidence Detected Across Region

A comprehensive analysis of satellite radar imagery since 2015 has detected rapidly increasing land subsidence extending hundreds of miles along the East Coast. Areas around major coastal cities like New York, Philadelphia, Baltimore, Washington D.C. and Norfolk are sinking over 5 times faster than sea levels are rising in the region.

“We find more evidence that coastal cities like Norfolk are sinking faster than global sea-level rise projections. Land subsidence will further exacerbate tidal flooding and permanent inundation of low-lying areas. Flooding from high tides and rain will disproportionally impact the underserved residents in these sinking coastal cities,” said Dr. Shimon Wdowinski, a professor at Florida International University.

The subsidence is caused by natural consolidation of geological formations as well as extensive withdrawal of groundwater, oil and gas. Researchers warn that failing to account for sinking landscapes means we’re underestimating the extent and severity of coastal flooding.

“It’s happening at a scale and magnitude much greater than we had understood,” said Dr. David Bekaert, geophysicist at NASA’s Jet Propulsion Laboratory.

East Coast Megapolises Face Crisis

Major East Coast cities including New York, Philadelphia, Baltimore and Washington D.C. are experiencing subsidence of over 15 millimeters per year, more than 5 times the global sea level rise rate. These crucial economic and political hubs are home to tens of millions of people and trillions in infrastructure.

And the problem is accelerating – since the 1990s the land has sunk over 30 centimeters in places like the Chesapeake Bay. According to the studies, some areas may sink more than 6 feet by 2100.

Photo of partially submerged buildings

Coastal buildings already experiencing regular flooding during high tides, Norfolk, VA. Source: Getty Images

“The rapidly sinking coastline represents an enormous threat to major sections of critical American infrastructure in big cities like New York City, Philadelphia, Baltimore and Washington D.C.,” said lead author Dr. Royhan Gani of the University of Arizona. “It’s likely to get much worse if climate change leads to more rapid ice sheet melt and sea level rise.”

Boston’s Logan Airport Sinking into Harbor

A new report from geologists warns that Boston’s Logan International Airport is slowly sinking into Boston Harbor. Land subsidence in the area is causing runways and infrastructure to subside at nearly 1 inch per year. Unless mitigation efforts are undertaken, large sections of the airport could be underwater before mid-century.

“Logan Airport is facing an existential crisis. Areas are already flooding during extreme high tides and storm surges today. And it’s only going to get worse as the land sinks and climate change drives sea level rise”, said report co-author Annie Baxter.

With over 200 daily flights and 31 million passengers per year, Logan is the largest transportation hub in New England and a vital economic engine for the region. But the land it was built on is compressing under its own weight, exacerbating flood risks.

“The airport basically sits on landfill, on clay and other materials that compress over time,” Baxter said.

Year Predicted Subsidence
2030 30 cm
2040 60 cm
2050 90 cm

Table 1. Predicted land subsidence at Boston’s Logan Airport to 2050 if no actions are taken. Source: MirageNews

Researchers estimate it could cost billions of dollars over the next 10-30 years to elevate or relocate Logan’s infrastructure to adapt to the subsidence crisis. But Boston’s Logan is not an isolated case – the analysis shows airports and seaports across the East Coast megaregion are grappling with similar risks.

Cascading Impacts to Coastal Communities

The sinking landscape poses severe threats to homes, businesses, roads, railways, subway systems, internet cables, toxic waste sites and more across huge swaths of the densely populated Atlantic coastline. Areas already experience frequent flooding during high tides and storms. As seas rise and land sinks further, the inundation will grow more severe.

Entire coastal neighborhoods and low-lying communities face the prospect of being permanently flooded out or destroyed during hurricanes and extreme weather events.

Photo of East Coast shoreline

Low-lying coastal areas already threatened by rising seas now face accelerated impacts from land subsidence. Source: MirageNews

The analysis shows these cascading climate impacts could spur mass migration from East Coast population centers in the coming decades if resilience measures aren’t implemented.

“We’re seeing tipping points being reached,” said Dr. Wdowinski. “What used to be once-in-a-lifetime floods will become annual events.”

Next Steps

More research is urgently needed to map at-risk regions and infrastructure to help vulnerable communities on the East Coast adapt.

Engineers also suggest massive infrastructure upgrades will be required in the near future – potentially including elevating or relocating highways, rail lines, subway tunnels, airports, data centers and power plants. Vast sums of government money will likely be required.

Seawalls, levees, surge barriers and strategies like deliberately flooding subway tunnels during storms could help buy coastal cities time.

But experts say the subsidence crisis underscores the need for forward-thinking adaptation and managed retreat from the most vulnerable areas. Difficult decisions around coastal infrastructure and development loom this decade for East Coast states and cities.

“We can’t escape the rate these cities are sinking,” said Dr. Gani. “Policymakers will need to make tough choices to help residents relocate away from flood zones.”

The analysis makes clear – from Boston down to Miami, time is running out to future-proof major sections of America’s East Coast as it disappears under rising seas and sinking lands.




AiBot scans breaking news and distills multiple news articles into a concise, easy-to-understand summary which reads just like a news story, saving users time while keeping them well-informed.

To err is human, but AI does it too. Whilst factual data is used in the production of these articles, the content is written entirely by AI. Double check any facts you intend to rely on with another source.

By AiBot

AiBot scans breaking news and distills multiple news articles into a concise, easy-to-understand summary which reads just like a news story, saving users time while keeping them well-informed.

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