81,000 years ago, global warming all the way back then? So which one of these guys was to blame?
Neanderthal or Cro Magnon?
Posted on 02/11/2010 1:29:33 PM PST by decimon
Theories about the rates of ice accumulation and melting during the Quaternary Period -- the time interval ranging from 2.6 million years ago to the present -- may need to be revised, thanks to research findings published by a University of Iowa researcher and his colleagues in the Feb. 12 issue of the journal Science.
Jeffrey Dorale, assistant professor of geoscience in the UI College of Liberal Arts and Sciences, writes that global sea level and Earth's climate are closely linked. Data he and colleagues collected on speleothem encrustations (see photo right), a type of mineral deposit, in coastal caves on the Mediterranean island of Mallorca indicate that sea level was about one meter above present-day levels around 81,000 years ago. The finding challenges other data that indicate sea level was as low as 30 meters -- the ice equivalent of four Greenland ice sheets -- below present-day levels.
He said the sea level high stand of 81,000 years ago was preceded by rapid ice melting, on the order of 20 meters of sea level change per thousand years and the sea level drop following the high water mark, accompanied by ice formation, was equally rapid.
"Twenty meters per thousand years equates to one meter of sea level change in a 50-year period," Dorale said. "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."
Dorale also noted that although their findings disagree with some sea level estimates, such as those from Barbados and New Guinea that come from ancient coral reefs, they are in agreement with data gathered from other sites such as the Bahamas, the U.S. Atlantic coastal plain, Bermuda, the Cayman Islands and California.
"There has been a long-standing debate on this issue, but our data is pretty robust," he said. "The key to our research is two-fold. First, the speleothem approach we employed is novel and extremely precise compared to other methods of sea-level reconstruction. Second, Mallorca appears to be particularly well suited to the task, because neither tectonics nor isostasy -- geological forces of crustal motion -- over-complicate the record. It's really close to the ideal scenario. It's also a heck of a nice place to do fieldwork."
Dorale's colleagues include Bogdan Onac of the University of South Florida, Tampa; Joan Fornos, Joaquin Gines and Angel Gines, all of the Universitat de les Illes Balears, Mallorca, Spain; Paola Tuccimei of the University of Rome III, Italy; and UI associate professor of geoscience David Peate.
The research was supported by the National Science Foundation in a grant to Dorale and Onac.
STORY SOURCE: University of Iowa News Services, 300 Plaza Centre One, Iowa City, Iowa 52242-2500 MEDIA CONTACT: Gary Galluzzo, writer, 319-384-0009, gary-galluzzo@uiowa.edu
Rising to the occasion ping.
“Twenty meters per thousand years equates to one meter of sea level change in a 50-year period,”
Somebody please show me where any CONUS coastline has changed 1 meter in the past 50 years????
More crapola!
So . . . slip-ons? . . . or chest waders?
Gills and wings. You'll need to become a fird.
81,000 years ago, global warming all the way back then? So which one of these guys was to blame?
Neanderthal or Cro Magnon?
More than 50 years, but there are remains of foundations of structures east of the beaches in some Jersey Shore communities from 80 or more years ago. But all it takes to do that is one huge nor'easter or hurricane, which scours away the sand and cuts back the coastline. And what the actual sea level was then, who knows?
Neanderthal or Cro Magnon?
Since both drove SUVs, they're equally responsible.
Not crapola. They have proof that the sea level changes naturally.
In other words, they’ve shown that global warming is natural.
Not man-made.
This is a big deal. This is peer-reviewed scientific proof against AGW.
Another global warming shill and demagogue. Thanks decimon.
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Darn, Civ! Well put!
Does your quote fit in a tag line? If not, it should.
:’) The first sentence does. :’)
Since both drove SUVs, they're equally responsible.
Ancient man also had luxury jets to ride around in. :D 
thanks decimon
The other type is called an "interstadial". They are less than 10,000 years long, and they occur "irregularly". For the most part no one has any idea why any particular "interstadial" happened.
At the present time it is possible we are 5,000 years past the end of the last Interglacial, with the extra time technically being an interstadial which could end tomorrow once the conditions causing it change.
Interstadials are highly important to humanity. The warm period referred to in the news story above is not an "interglacial" but an "interstadial". It lasted a few thousand years, the oceans rose, it went away, the water went back to the poles as ice and snow ~ probably powered a glacial advance in the North American ice sheet in fact.
Another "interstadial" about 35,000 years ago allowed Cro Magnon man to enter Europe. It lasted a while. Things went cold again. The Neanderthals died out, and possibly the original Cro Magnons who moved to Europe died out leaving only a small remnant population hanging onto the Franco-Spanishborder region.
Going the other way around there are sometimes short-lived periods of glaciation within the framework of an interglacial. The Younger Dryas appears to have been one such. The Little Ice Age was probably another ~ and it may not be over.
At some point we will tip over into the next glacial period and billions of people will die.
Greenland and Antarctic ice core data suggests we are so close to that point that we could find the snows piling up just any time.
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