MANTOLOKING, N.J.—A new study looking back over 1,000 years finds the flooding risk along the New York and New Jersey coasts increased greatly after industrialization, and major storms that once might have occurred every 500 years could soon happen every 25 years or so.
The study by Penn State, Rutgers, Princeton, and Tufts universities, and Massachusetts Institute of Technology, finds that flood heights have risen nearly 4 feet since the year 850, largely because of a sea level rise. The study advocates better risk management strategies to cope with storms.
It was released a month before the third anniversary of Superstorm Sandy, which devastated the coasts of New York and New Jersey.
"A storm that occurred once in seven generations is now occurring twice in a generation," said Benjamin Horton of Rutgers, one of six lead researchers involved in the study. "What we do know is that as sea level rise accelerates into the future, we are going to have more frequent flooding."
The study was published Monday in the Proceedings of the National Academy of Sciences journal.
The researchers said that in a changing climate, future inundation of the U.S.'s Atlantic Coast will depend on storm surges during tropical cyclones and the rising sea levels on which those surges occur. However, the record of tropical cyclones in the North Atlantic Basin is too short to draw meaningful conclusions, from 1851 to the present.
To reconstruct sea levels for earlier periods, the research team used microfossils, called foraminifera, that were preserved in sediment cores from coastal salt marshes in Cape May Court House and Galloway, New Jersey.