Major cities along the US Atlantic coast are sinking faster than previously thought, with some subsidence rates outpacing global sea level rise, threatening buildings, roads and other key infrastructure.
According to new research published in the scientific journal PNAS Nexus, urban centers such as New York City, Long Island, Baltimore, Virginia Beach and Norfolk are experiencing subsidence rates of up to 5 millimeters per year.
Researchers warn that such rapid subsidence could weaken building foundations, damage roads, gas and water lines, and exacerbate coastal flooding, especially with sea level rise along the coast caused by climate change.
“The continued subsidence on the US East Coast should cause concern,” said Leonard Ohenhen, lead author of the study from Virginia Tech.
“This is especially the case in areas with high population and property density, where there has been a historical neglect of infrastructure maintenance,” Dr. Ohenhen said.
Analyzing data from a variety of sources, including space-based radar satellites, scientists have created digital maps showing exactly where collapsed land poses a risk to the health of vital infrastructure.
They have measured millions of land subsidence events over the years and created some of the world’s first high-resolution maps of this process.
Researchers found that a large area of the East Coast is subsiding at least 2 millimeters per year, affecting more than 2 million people and 800,000 properties.
“The problem is that the hotspots of sinking land intersect directly with population and infrastructure centers,” Dr. Ohenhen said.
According to the study, 3,700 square kilometers are falling at a rate of more than 5 millimeters per year, which is more than the global rate of sea level rise of 4 millimeters per year.
Overall, scientists say that about 2,000 to 74,000 square kilometers of land area, home to 1.2 to 14 million people and 476,000 to 6.3 million properties, and more than half of all infrastructure in major cities such as New York, Baltimore and Norfolk, are subject to subsidence rates of 1 to 2 millimeters per year.
Manoochehr Shirzaei, co-author of the study, said: “With this study we underline that land subsidence is not an abstract threat. It affects you, me and everyone, it may be gradual but its effects are real.”
Giving an example of the effects of this collapse, the researchers say that significant areas of critical infrastructure, such as New York’s JFK and LaGuardia airports and runways, as well as rail systems, were affected.
“Their current and future impacts are potential damage to infrastructure and increased flood risks,” Dr. Ohenhen added.
https://www.independent.co.uk/climate-change
