Beach building is keeping the Atlantic Coast from going under
The artificial build-up of beaches is buffering the U.S. Atlantic coastline against the effects of sea level rise, but that benefit may not last as sand gets harder to come by in the coming decades.
To analyze patterns of shoreline change along the Atlantic Coast, researchers used U.S. Geological Survey records from 1830 to 2007 along more than 2,500 kilometers (1,553 miles) of shoreline, from Massachusetts to South Florida.
The study's authors were surprised to find a stark contrast between historical and recent rates of shoreline change. The authors expected to see a broad pattern of intensified erosion. Instead, they saw the opposite. Their results indicate that after 1960, shoreline position tended to shift seaward at an average rate of 5 centimeters (2 inches) per year.
"The weird thing was that in these long-term records, we would have expected to see a lot more erosion than we're seeing. The question was why," said Eli Lazarus, a lecturer in geomorphology at the University of Southampton in the U.K. and one of the authors of a new study published in Earth's Future, a journal of the American Geophysical Union.
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