NASA Maps Suggest Tens of Millions of People at Risk – Executive Summary

Newsweek reported Thursday that the future of the U.S. East Coast is threatened not only by rising sea levels, but also by the sinking land itself.

A team of scientists from Virginia Tech's NASA-funded Earth Observation and Innovation Laboratory found that the geographic problem “is happening fast enough to threaten the infrastructure, farmlands, and wetlands that tens of millions of people along the coast depend on,” NASA explained. .

Scientists analyzed satellite data and GPS sensors to monitor coastal movement and found that major cities like New York, Baltimore and Norfolk, Virginia, were built on land that sank between 2007 and 2020 — on average, 1 to 2 millimeters per year, but Some counties, in Delaware, Maryland, South Carolina and Georgia, saw their lands sink two or three times faster.

“We analyzed satellite radar data to assess how land subsidence increases the vulnerability of communities, properties and infrastructure to coastal hazards. Our key findings indicate that between 2,000 and 74,000 square kilometers of land area, inhabited by 1.2 to 14 million people Between 476,000 and 6.3 million properties are sinking at a rate of 1 to 2 mm per year, study authors.

“Land sinking affects more than half of the infrastructure in many major cities, exposing them to an increased risk of flooding and other coastal hazards,” he stressed.

This subsidence could exacerbate the effects of sea level rise, which is estimated to exceed 30 cm on most US coasts by 2050, and lead to increased levels of tidal flooding and damage to homes and infrastructure.

The city of Charleston, South Carolina, is one of the fastest growing cities, sinking at a rate of about 4 mm every year. This subsidence, exacerbated by rising sea levels, could be catastrophic for the city, most of which is already located less than 3 meters above sea level.