A new study published in Science this week (Dorale et al 2010) indicates sea level can rise extremely quickly, as fast as “Twenty meters per thousand years [which] equates to one meter of sea level change in a 50-year period,” according to lead author Jeffrey Dorale, an assistant professor of geoscience at the University of Iowa. “Today, over one-third of the world’s population lives within 60 miles of the coastline. Many of these areas are low-lying and would be significantly altered—devastated—by a meter of sea level rise. Our findings demonstrate that changes of this magnitude can happen naturally on the timescale of a human lifetime. Sea level change is a very big deal.”
ScienceNOW Daily News
11 February 2010
Something very unusual happened about 80,000 years ago, as Earth’s last ice age was getting started. Sea levels that had been dropping for thousands of years–as more and more water became trapped in expanding glaciers–suddenly rose, according to a new study. Then after a few thousand years, the levels fell again. Although the researchers haven’t found the cause of this phenomenon, they say the findings could force at least a partial rethinking of the mechanisms governing Earth’s climate.
In coastal caves on the Spanish island of Mallorca in the Mediterranean Sea, the team studied stalactites encrusted with calcite. They measured the elevation of those encrustations, which were deposited like bathtub rings that mark high- and low-water levels, and then dated those deposits using the radioactive decay of traces of uranium into thorium isotopes. Based on those calculations, the researchers found that sea level 80,000 years ago had rebounded to the point where it rose 1 meter higher than it is today. And it could have risen quite quickly, as much as 2 meters per century, says geochemist and lead author Jeffrey Dorale of the University of Iowa, Iowa City.
link to the full story in Science Now here
Dorale, J. A., B. P. Onac, J. J. Fornos, J. Gines, A. Gines, P. Tuccimei, and D. W. Peate. Sea-Level Highstand 81,000 Years Ago in Mallorca. Science 327:860-863..”]