Tuesday, December 29, 2009

Sea level rise quickening along US east coast

Sandy Bowers in the Philadelphia Inquirer: Looking deep into the geologic past, researchers at the University of Pennsylvania have learned that along the Atlantic Coast, including New Jersey, sea level rose three times faster during the 20th century than it did during the previous 4,000 years.

At one location in North Carolina, they fixed the date of the rapid acceleration to between 1879 and 1915, after the Industrial Revolution had taken deep hold, lending credence to the connection between the rising temperatures that occurred then and rising sea levels.

"If that happened in the past, it gives you strong confidence that the predictions of increased sea-level rise in the 21st century are true," said lead researcher Benjamin P. Horton, a professor in Penn's sea-level research laboratory.

Scientists predict sea levels will rise as a result of global warming, "but by how much, when, and where it will have the most effect is unclear," Horton said. "Lots of people are looking at the future," he said. "The problem is, they've been looking at the future without having the information to understand the past."

Horton also can't predict the rise in particular Jersey Shore towns. Still, he and others said the studies suggested a strong acceleration in overall sea-level rise along the U.S. Atlantic Coast, including in New Jersey and Delaware. Levels there are rising not only because of higher water - due to melting polar ice and expansion of a warmer ocean - but because the land is sinking.

…The rate in New Jersey is about one inch every 10 years, faster than anywhere along the coast from Maine to South Carolina and double the rate in Boston or Charleston, S.C., Horton says. "The important thing to realize," Horton said, "is that sea level is going up due to two factors." Not just because the ocean is rising, but also because the land is subsiding…

A 1944 aerial view of New Jersey from Cape May to Normandy Beach. Approx geographic coverage: South: 38.93 deg. N, 74.98 deg. W North: 39.98 deg. N, 74.07 deg. W Aerial flight service: Flight A, 16th Photo Squadron, US Army.

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