sea level rise According to NASA, it's threatening the East Coast of the United States, but that's not the only thing to worry about. Images shared by the space agency on Tuesday show that the coast is indeed sinking. Major cities such as New York And Baltimore.
The discovery was made by a team of scientists at Virginia Tech's NASA-funded Earth Observation and Innovation Laboratory. geographical issues “It is happening fast enough to threaten the infrastructure, farmland, and wetlands that tens of millions of people along the coast depend on,” NASA said.
Scientists examined satellite data and GPS sensors to monitor coastal movements and found that infrastructure in major cities such as New York, Baltimore and Norfolk, Virginia, were built on land that had sunk between 2007 and 2020. Or, it sinks by an average of 1 to 2 mm per year. But some counties in Delaware, Maryland, South Carolina and Georgia have seen land sink two or three times faster than that.
Scientists have found that land in wetlands sinks by more than 3 millimeters a year. Forests were also moved due to seawater intrusion and land subsidence.
And it's not just wildlife that's affected. Along the coast, at least 897,000 structures, including highways and airports, lie on sinking land.
Results from another study from Virginia Tech's lab were published in PNAS Nexus.
The map shared by NASA was created using satellite data from the United States, Japan, and Europe. They show that the mid-Atlantic region is sinking more. This shows that the region is sinking downward due to the Laurentian Ice Sheet, which began retreating 12,000 years ago. The sinking continues today, which in turn causes parts of the United States and Canada to rise.
One of the fastest sinking cities is Charleston, whose downtown is only 10 feet above sea level. The city experiences subsidence of about 4 mm per year. The city is home to about 800,000 people, and some of the sinking is due to human activities such as groundwater pumping, according to NASA.
To prevent tidal flooding, the city is considering an 8-mile-long seawall to protect against storm surges.
Virginia Tech geophysicist Leonard Ohenhen said the issue of subsidence is “harmful” and “overlooked” compared to sea level rise. But it's still a big problem, and people living along the coast could see more damage to their homes, saltwater intrusion into their farms and freshwater supplies, and more.
But subsidence is a problem that can be slowed regionally, said Manoochehr Shirzaei, co-author of both studies and director of the Virginia Tech Research Institute. Groundwater extraction, dams, and other infrastructure can also cause subsidence.
The lab will next use these research techniques in the Gulf Coast, with the goal of mapping all of the world's coastlines, Shirzaei said.