Satellite imagery has revealed that major cities along the U.S. Atlantic coast are experiencing land subsidence, with some areas sinking at rates of 2 to 5 millimeters per year, a pace faster than previously estimated. This phenomenon, known as subsidence, poses significant risks to infrastructure and communities in vulnerable coastal areas.
A recent paper published in the Proceedings of the National Academies of Sciences by researchers from Virginia Tech and the U.S. Geological Survey emphasizes the implications of this subsidence for planning community and infrastructure resilience.
The affected regions include populous areas such as New York City, Baltimore, Virginia Beach, and Norfolk. The subsidence exacerbates the impact of climate change-induced storms and weather issues, as the sinking land amplifies the vulnerabilities of these coastal areas.
Lead author Leonard Ohenhen, a graduate student at Virginia Tech, warns of the continuous and unmitigated subsidence causing concern, particularly in areas with high population density and historical complacency toward infrastructure maintenance.
The research team utilized satellite imagery and radar data to create digital terrain maps, pinpointing areas where land subsidence poses the most significant risks to vital infrastructure. The analysis, based on data from multiple years, indicates that a large portion of the East Coast is sinking at a rate of at least 2 mm per year. Notably, areas along the mid-Atlantic coast spanning over 3,700 square kilometers are experiencing subsidence rates exceeding 5 mm per year.
Adding complexity to the issue is the global sea level rise, estimated at about 4 mm per year. The study highlights that subsidence rates of 2 mm per year impact over 2 million people and 800,000 properties on the East Coast. The paper, titled “Slowly but surely: Exposure of communities and infrastructure to subsidence on the US east coast,” reveals that critical infrastructure in major cities, including airports and railway systems, intersects with the identified hotspots of sinking land.
The authors underscore the tangible and real impacts of subsidence, emphasizing its gradual but substantial consequences. The exposure of communities, assets, and infrastructure systems to subsidence on the East Coast is extensive, affecting millions of people and properties. The study argues that the problem is not merely the sinking land itself but the intersection of sinking land hotspots with population and infrastructure hubs.
The information provided in the study is deemed essential, as it addresses a gap in understanding and emphasizes the urgency of addressing subsidence-related risks. The research sheds light on the need for proactive measures in infrastructure planning and community resilience to mitigate the potential damage and increased flood risks associated with land subsidence along the U.S. Atlantic coast.