2024-01-03 12:53:32
Major cities on the US Atlantic coast are sinking, in some cases up to 5 millimeters per year, a rate that far exceeds global sea level rise. This is confirmed by new research from Virginia Tech and the United States Geological Survey.
Particularly hard-hit population centers, such as New York City and Long Island, Baltimore, Virginia Beach and Norfolk, are seeing areas of rapid “sinking” along with slower sinking or relatively stable terrain, increasing the risk for roads, building foundations, railway lines and pipelines, according to a study now published in PNAS Nexus.
“Continued and absolute subsidence off the East Coast of the United States should cause concern,” said lead author Leonard Ohenhen, a graduate student working with associate professor Manoochehr Shirzaei at Virginia Tech’s Earth Observation and Innovation Laboratory. : “This is particularly in areas with high population and property density and a historical complacency towards infrastructure maintenance.”
Shirzaei and his research team gathered a vast collection of data points measured by space-based radar satellites and used this high-precision information to build digital terrain maps that show exactly where sinking landscapes pose risks to infrastructure health. vital. Using publicly available satellite images, Shirzaei and Ohenhen measured millions of instances of land subsidence over several years. They then created some of the world’s first high-resolution representations of land subsidence.
These innovative new maps show that a large area of the East Coast is sinking at least 2 mm per year, and several areas along the mid-Atlantic coast of up to 3,700 square kilometers are sinking more than 5 mm per year, more than the current global rate of sea level rise of 4 mm per year.
“We measure subsidence rates of 2mm per year affecting more than 2 million people and 800,000 properties on the East Coast,” Shirzaei said. “We know to some extent that the land is sinking. Through this study, we highlight that land subsidence is not an intangible threat. It may be gradual but the impacts are real.”
Multiple critical infrastructures affected
In several cities along the East Coast, multiple critical infrastructures, such as roads, railways, airports, and levees, are affected by different rates of subsidence.
“The problem here is not just that the land is sinking. The problem is that critical points of sinking land intersect directly with population and infrastructure centers,” Ohenhen said. “For example, major areas of critical infrastructure in New York, including JFK and LaGuardia airports and their runways, along with rail systems, are affected by subsidence rates exceeding 2 mm per year. The effects of this now and in the future are potential damage to infrastructure and increased risks of flooding.
Subsidence can undermine the foundation of the building; damage roads, gas and water lines; cause buildings to collapse; and exacerbate coastal flooding, especially when combined with sea level rise caused by climate change.
“This information is needed. No one else is providing it,” said Patrick Barnard, a USGS research geologist and co-author of the study: “Shirzaei and his team at Virginia Tech entered that niche with their technical expertise and are providing something extremely valuable.”
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