Scientists have made a startling discovery that could impact more than 15 million Americans – nearly all of the US East Coast is sinking.
Virginia Tech researchers identified ‘hotspots’ from Florida to New Hampshire that are dropping as much as five millimeters a year due to groundwater extraction and the weight of infrastructure.
The team collected data from space-based radar sites to build digital terrain maps of the East Coast to show where sinking landscapes present risks to the health of vital infrastructure.
Particularly hard-hit population centers such as New York City and Long Island, Baltimore, Maryland, Virginia Beach and New Haven, Connecticut are seeing areas of rapid ‘subsidence.’
Virginia Tech researchers identified 800,000 properties from Florida to New Hampshire that are dropping as much as five millimeters a year
Lead author Leonard Ohenhen, a graduate student at Virginia Tech, said: ‘Continuous unmitigated subsidence on the. East Coast should cause concern.
‘This is particularly in areas with a high population and property density and a historical complacency toward infrastructure maintenance.’
The team found several areas along the mid-Atlantic coast of more than 1,400 square miles are sinking more than five millimeters per year, more than the current four millimeters per year global rate of sea level rise.
There are 25 millimeters in one inch.
‘The percent land area within each county affected by subsidence on the US east coast has important implications for flood frequency and severity in the different communities,’ reads the study published in PNAS.
‘Land subsidence can potentially increase the flooded area during coastal storm events by modifying the base flood elevations and topographic gradients.’
Ohenhen and his professor Manoochehr Shirzaei used satellite data from 2007 to 2020 published by the United States Geological Survey.
The sinking land also impacted major infrastructure like roads, trains and railways across the East Coast
Pictured is a satellite image of roads in Virginia
‘We highlight 12 metropolitan cities affected by spatially variable land subsidence: Boston (Massachusetts [MA]), Providence (Rhode Island [RI]), New Haven (Connecticut [CT]), New York (New York [NY]), Atlantic City (New Jersey [NJ]), Baltimore (Maryland [MD]), Norfolk (Virginia [VA]), Wilmington (North Carolina [NC]), Charleston (South Carolina [SC]), Jacksonville (FL), and Miami (FL),’ reads the study.
The team found that most of the East Coast is sinking by two millimeters yearly, impacting around 2.1 million people.
According to the study, that amount does not include the 16 million others living in regions dipping more significantly.
Several areas in Atlantic City, Savannah, and Charleston were observed to be subsiding with rates faster than four millimeters per year.’
Parts of New Jersey and Delaware have subsidence rates of at least three millimeters per year.
The team also broke down the data by county, revealing that 138 to 163 counties have sinking averages of one millimeter per year and 56 to 152 counties at two millimeters per year.
That also included popular airports: John F. Kennedy International Airport (JFK) is sinking 1.7 mm per year
However, the team identified hotspot counties with higher hazard severity: Hampton (VA), Norfolk (VA), Virginia Beach (VA), Chesapeake (VA), Baltimore City (MD), Union (NJ), Middlesex (NJ), Monmouth (NJ), Ocean (NJ), New Haven (CT), and several counties in New York City (Queens, Bronx, Nassau, and Westchester).
The sinking land also impacted major infrastructure like roads, trains and railways across the East Coast.
That also included popular airports: John F. Kennedy International Airport (JFK) is sinking 1.7 mm per year, LaGuardia Airport 1.5 mm per year, Newark Liberty International Airport (EWR) 1.4 mm per year, and Boston Logan International Airport has a median subsidence rate of 1.1 mm per year.
‘Here, the problem is not just that the land is sinking. The problem is that the hotspots of sinking land intersect directly with population and infrastructure hubs,’ said Ohenhen.
‘For example, significant areas of critical infrastructure in New York, including JFK and LaGuardia airports and its runways, along with the railway systems, are affected by subsidence rates exceeding two mm per year.
‘The effects of these right now and into the future are potential damage to infrastructure and increased flood risks.’
