Post by jonsdigs on Dec 13, 2006 13:55:10 GMT -5
Archive of history in stalagmite
An Oregon Caves' spike tells of ice ages and warming periods with climate data for 14,000 years
The Oregonian
Wednesday, December 13, 2006
RICHARD L. HILL
CORVALLIS -- The foot-long spike of chalk-colored rock doesn't look like much outside its home in the Oregon Caves. But the stalagmite has given scientists their first precise look at southwest Oregon's past climate.
Before it was broken from the cave floor in the 1930s, the stalagmite appears to have recorded the first decades of global warming from about 1800 as the industrial age and its emissions of greenhouse gases began.
Paleoclimatologists at Oregon State University say their research is in its early stages, but the sample that sprouted from the cave floor over thousands of years is revealing information about climate not only from the industrial era but over the past 14,000 years.
"The stalagmite is giving us a detailed climate record over a long time span, which makes it unique," said Alan Mix, an isotope geochemist and a research project leader. "We're seeing climate results for Oregon that no one has ever seen before."
The research shows the natural climate fluctuations of the past, which can be compared with today's human-influenced climate. The preliminary findings show how Oregon climate has changed during the past 11 centuries and hint at how closely linked it is to global trends.
Last year, the researchers reported in the journal Quaternary Research that southwest Oregon cooled 12,800 years ago, the same time as an abrupt 1,300-year cold period called the Younger Dryas that originated in the North Atlantic Ocean.
The stalagmite data also suggest a sharp rise in temperatures about 1100 A.D., during what is called the "Medieval Warm Period," and a dip in temperature around 1650 during the "Little Ice Age."
"Understanding how the climate system has changed in the past will give us a better understanding of what to expect in the future as the impact of global warming becomes more pronounced," said Peter Clark, an OSU professor of geosciences and a project leader.
Lica Ersek, a doctoral student with the OSU Paleoclimate Research Group, is presenting the most recent findings this week at the American Geophysical Union's annual fall meeting in San Francisco.
The stalagmite is on loan from the 484-acre Oregon Caves National Monument, about 50 miles southeast of Grants Pass. Workers broke off the stalagmite and other formations during the 1920s and 1930s while widening passages through the cave, which is made up of a series of interconnected chambers.
Full Article
An Oregon Caves' spike tells of ice ages and warming periods with climate data for 14,000 years
The Oregonian
Wednesday, December 13, 2006
RICHARD L. HILL
CORVALLIS -- The foot-long spike of chalk-colored rock doesn't look like much outside its home in the Oregon Caves. But the stalagmite has given scientists their first precise look at southwest Oregon's past climate.
Before it was broken from the cave floor in the 1930s, the stalagmite appears to have recorded the first decades of global warming from about 1800 as the industrial age and its emissions of greenhouse gases began.
Paleoclimatologists at Oregon State University say their research is in its early stages, but the sample that sprouted from the cave floor over thousands of years is revealing information about climate not only from the industrial era but over the past 14,000 years.
"The stalagmite is giving us a detailed climate record over a long time span, which makes it unique," said Alan Mix, an isotope geochemist and a research project leader. "We're seeing climate results for Oregon that no one has ever seen before."
The research shows the natural climate fluctuations of the past, which can be compared with today's human-influenced climate. The preliminary findings show how Oregon climate has changed during the past 11 centuries and hint at how closely linked it is to global trends.
Last year, the researchers reported in the journal Quaternary Research that southwest Oregon cooled 12,800 years ago, the same time as an abrupt 1,300-year cold period called the Younger Dryas that originated in the North Atlantic Ocean.
The stalagmite data also suggest a sharp rise in temperatures about 1100 A.D., during what is called the "Medieval Warm Period," and a dip in temperature around 1650 during the "Little Ice Age."
"Understanding how the climate system has changed in the past will give us a better understanding of what to expect in the future as the impact of global warming becomes more pronounced," said Peter Clark, an OSU professor of geosciences and a project leader.
Lica Ersek, a doctoral student with the OSU Paleoclimate Research Group, is presenting the most recent findings this week at the American Geophysical Union's annual fall meeting in San Francisco.
The stalagmite is on loan from the 484-acre Oregon Caves National Monument, about 50 miles southeast of Grants Pass. Workers broke off the stalagmite and other formations during the 1920s and 1930s while widening passages through the cave, which is made up of a series of interconnected chambers.
Full Article