And now, land may be sinking
Study suggests mid-Atlantic is getting lower, which may exacerbate effects of sea-level rise
In the coming decades, cities and towns up and down the eastern seaboard will have to come to terms with the impact of rising sea level due to climate change. A new study, however, is suggesting that rising sea levels may be only part of the picture — because the land along the coast is also sinking.
That’s the key finding of Professor of Earth and Planetary Sciences Peter Huybers, Frank B. Baird Jr. Professor of Science Jerry Mitrovica, and Christopher Piecuch, an assistant scientist at the Woods Hole Oceanographic Institution, who used everything from tide gauges to GPS data to paint the most accurate picture ever of sea-level rise along the east coast of the U.S. The researchers are co-authors of the study, recently published in Nature.
“What we are seeing at a large scale, and this was a surprise to me, is a very clear pattern that you would expect if the response to the last ice age were the primary control on the differential rates of sea-level rise across the eastern U.S.,” said Huybers. In other words, between 20,000 and 95,000 years ago, the Laurentide Ice Sheet, which covered most of northern North America, levered the land upwards. “Now, thousands of years after the ice is gone,” Huybers said, “the mid-Atlantic crust is still subsiding.
“In New England, there is not too much additional sea-level rise from land motion because it’s near the hinge point,” he continued. “The bulge caused by the ice sheet was centered on the mid-Atlantic, and because it’s still settling down, the relative rise of sea level in the mid-Atlantic is about twice the global average.”