NASA has raised concerns about the sinking of the East Coast of the United States, revealing that satellite images depict a gradual decline in coastal land, including areas hosting major cities such as New York and Baltimore.
A team of scientists at Virginia Tech’s Earth Observation and Innovation Lab, funded by NASA, discovered this troubling trend, which poses a significant threat to infrastructure, farmland, and wetlands relied upon by tens of millions of coastal residents.
By analyzing satellite data and GPS sensors, researchers observed land subsidence, or sinking, averaging 1 to 2 millimeters annually between 2007 and 2020. However, certain regions in Delaware, Maryland, South Carolina, and Georgia experienced subsidence rates that were two to three times higher.
NASA Images (Credits: CBS News)
Marshlands were particularly affected, sinking by over 3 millimeters annually, while the intrusion of saltwater and sinking land displaced forests. Approximately 897,000 structures, including highways and airports, are situated on subsiding land along the coast, exacerbating the risk of damage and flooding.
The findings, published in PNAS Nexus, underscore the urgency of addressing this issue. NASA’s maps, compiled from data collected by satellites from the U.S., Japan, and Europe, illustrate that the Mid-Atlantic region faces heightened sinking, attributed to the retreat of the Laurentide ice sheet over 12,000 years ago.
The sinking persists today, with implications extending across the U.S. and Canada. Charleston emerges as one of the cities most vulnerable to subsidence, with downtown areas hovering just 10 feet above sea level and experiencing a subsidence rate of approximately 4 millimeters per year.
Human activities like groundwater extraction contribute to this phenomenon, prompting discussions about constructing an 8-mile seawall to mitigate storm surges.
Leonard Ohenhen, a geophysicist at Virginia Tech, characterized subsidence as a “pernicious” and “overlooked” issue compared to rising sea levels.
Nevertheless, it poses significant challenges, including increased home damage, saltwater infiltration into farms and freshwater supplies, and other environmental complications.
However, subsidence is not without recourse. Manoochehr Shirzaei, director of the Virginia Tech lab, highlighted local interventions such as groundwater management and infrastructure adjustments as potential solutions.
The lab aims to expand its research to the Gulf Coast, with ambitions to map coastlines worldwide, offering valuable insights into addressing this pressing global issue.
