US Cities Sinking on the East Coast, Threatening Critical Infrastructure

A study has highlighted the speed at which U.S. cities along the East Coast are sinking as sea levels continue to rise, potentially threatening vital infrastructure hot spots.

Some areas along the U.S. Atlantic coast are sinking at a rate of 5 millimeters (0.2 inches) per year, the study published in the Proceedings of the National Academies of Sciences reported. Places mentioned in the report include New York City, Long Island, Baltimore, Norfolk and Virginia Beach.

This subsidence is largely a result of climate change. Global warming is causing a rise in sea levels, meaning coastal areas are particularly at risk. Experts estimate that the ocean is absorbing more than 90 percent of greenhouse gases in the atmosphere, which is also causing sea water to expand. And, as the world warms, glaciers and ice sheets are melting, feeding into the world's oceans.

"Continuous unmitigated subsidence on the U.S. East Coast should cause concern," lead author Leonard Ohenhen, a graduate student who works with associate professor Manoochehr Shirzaei at Virginia Tech's Earth Observation and Innovation Lab said in a press release detailing the findings. "This is particularly in areas with a high population and property density and a historical complacency toward infrastructure maintenance."

Entire areas are not likely to sink, as the study notes that there is stable ground which is not in danger of subsiding. However, the areas at risk interlink closely with "population and infrastructure hubs."

"For example, significant areas of critical infrastructure in New York, including JFK and LaGuardia airports and its runways, along with the railway systems, are affected by subsidence rates exceeding 2 mm per year," Ohenhen said. "The effects of these right now and into the future are potential damage to infrastructure and increased flood risks."

To reach these findings, Ohenhen, Shirzaei and colleagues built terrain maps from data gathered by satellites. These maps pinpointed exactly the areas that were sinking and the risks this poses to buildings and other infrastructure. They discovered that a notable area of the East Coast is sinking by at least 2 mm each year. Along the mid-Atlantic coast, some areas are sinking by over 5 mm per year. This is more than the current 4 mm of global sea level rise, the study reported.

Although many may not see this as an immediate problem, the study indicates there is cause for concern.

"We measured subsidence rates of 2 mm per year affecting more than 2 million people and 800,000 properties on the East Coast," Shirzaei said. "We know to some extent that the land is sinking. Through this study, we highlight that sinking of the land is not an intangible threat. It affects you and I and everyone, it may be gradual, but the impacts are real."

The U.S. is not the only country at risk, with coastal areas all over the globe potentially threatened in the not so distant future.

"Sea level rise poses a significant threat to low-lying coastal areas and coastal communities," Zita Sebesvari, a senior scientist at the United Nations University—Institute for Environment and Human Security (UNU-EHS), previously told Newsweek.

"As sea levels continue to rise, coastal areas are at risk of flooding, coastal erosion and salinization of soils and water sources," Sebesvari said. "Erosion and flooding can damage infrastructure, homes, and businesses, and even displace people from their homes. Areas particularly at risk from sea level rise are low-lying coastal regions and small island nations."

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