ATHENS, Ohio (Aug. 19, 2008) – A stalagmite in a West Virginia cave has yielded the most detailed geological record to date on climate cycles in eastern North America over the past 7,000 years. The new study confirms that during periods when Earth received less solar radiation, the Atlantic Ocean cooled, icebergs increased and precipitation fell, creating a series of century-long droughts.
A research team led by Ohio University geologist Gregory Springer examined the trace metal strontium and carbon and oxygen isotopes in the stalagmite, which preserved climate conditions averaged over periods as brief as a few years. The scientists found evidence of at least seven major drought periods during the Holocene era, according to an article published online in the journal Geophysical Research Letters.
“This really nails down the idea of solar influence on continental drought,” said Springer, an assistant professor of geological sciences.
The sun is not a reliable supplier of light radiation. You can't trust the sun. It gets all bent out of shape by magnetic field fluctuations.
Geologist Gerald Bond suggested that every 1,500 years, weak solar activity caused by fluctuations in the sun’s magnetic fields cools the North Atlantic Ocean and creates more icebergs and ice rafting, or the movement of sediment to ocean floors. Other scientists have sought more evidence of these so-called “Bond events” and have studied their possible impact on droughts and precipitation. But studies to date have been hampered by incomplete, less detailed records, Springer said.
But we hopefully have hundreds of years to prepare for the next megadrought.
The climate record suggests that North America could face a major drought event again in 500 to 1,000 years, though Springer said that manmade global warming could offset the cycle.
If humans survive for the next 500 years and I'm still alive in a rejuvenated body I'm looking forward to the opportunity to do climate engineering to prevent a massive drought.
|Share |||Randall Parker, 2008 August 20 11:11 PM Climate Trends|