These 28 major U.S. cities are sinking, new study finds — and researchers say damage may only appear when it's "potentially catastrophic"

New York, Dallas, Seattle and 25 other major U.S. cities are sinking, threatening the structural integrity of buildings, roads, dams and other forms of infrastructure, new research found. The study's authors say it represents a looming threat to the infrastructure of these cities, which combined are home to some 34 million people.

The study by Virginia Tech researchers, published in the journal Nature Cities on Thursday, used satellite-based radar measurements to visualize movement of the land underneath the nation's most populated cities, which they say is largely due to groundwater extraction. 

In all 28 of the cities they analyzed, at least 20% of urban areas are sinking, the researchers said. In 25 of the cities, they found at least 65% of the area is sinking, and more than 29,000 buildings are located in "high and very high damage risk areas, indicating a greater likelihood of infrastructure damage."