The East Coast of the United States faces a double risk: rising sea levels and sinking cities

Images shared by POT revealed a worrying scenario for the eastern coasts of USA: not only is sea level rising, but the land on which important cities such as NY and Baltimore is sinking.

A team of scientists funded by the POT and based on the Virginia Tech Earth Observation and Innovation Laboratory assured that this geographical problem “it is happening fast enough to threaten infrastructure, farmland and wetlands” on which tens of millions of people along the coast depend.

The study, published in PNAS Nexus and collected by CBS Newsused satellite data and GPS sensors to monitor coastal movement, discovering that between 2007 and 2020, the land under key infrastructure in cities such as NY, Baltimore and Norfolk, Virginiaexperienced an average subsidence of 1 to 2 millimeters per year.

However, in certain counties of Delaware, Maryland, South Carolina and Georgia, the ground sank up to two or three times faster. It was also discovered that the ground in the swamps is sinking more than 3 millimeters per year, also displacing forests due to the intrusion of salt water. One of the cities that is sinking the fastest is Charlestonwhere the center is just 3 meters above sea level, and sees subsidence of approximately 4 millimeters per year.

Around 800,000 people live in the city, and it is estimated that some of the subsidence is caused by human activities such as groundwater extraction. Before this panorama, Charleston Are you considering build a 13 kilometer sea wall around the peninsula to protect its center from storm flooding.

The images used in this study were created with data from satellites USA, Japan and Europeand show that the region of Mid-Atlantic It is sinking further, due to the retreat of the ice sheet Laurentide that began 12,000 years ago, causing the region to sink while parts of USA and Canada they rise. This phenomenon continues today.

“The problem of subsidence is pernicious and has been overlooked” compared to sea level rise, he noted Leonard Ohenhengeophysicist Virginia Tech. However, it is a big problem that can cause further damage to homes, saltwater infiltration into farms and freshwater supplies, among other challenges.

Along the coast, at least 897,000 structures—including roads and airports—are built on land that is sinkingwarned Manoochehr Shirzaeico-author of both studies and director of the laboratory at Virginia Tech

The laboratory researchers in Virginia Tech They intend to apply these research techniques in the Gulf Coastwith the aim of mapping all the coasts of the world and determining if it is a global phenomenon.