Sunday, January 24, 2010

Arizona cave shows abrupt Pleistocene climate shifts

A paper by UA geosciences professor Julia Cole and colleagues to be published next month in Nature Geoscience provides the first documentation that "the abrupt changes in Ice Age climate known from Greenland also occurred in the southwestern U.S."
 
"It's a new picture of the climate in the Southwest during the last Ice Age," Julia said. "When it was cold in Greenland, it was wet here, and when it was warm in Greenland, it was dry here."  The team analyzed thousands of micro-slices of a stalagmite from an Arizona cave, to track evidence of climate from 55,000 to 11,000 years ago. [right, a slice of a stalagmite core before samples are taken from it. The creamy or yellow area upper half of the slice is the region that can be tested to reveal past climate. The reddish, pockmarked region on the bottom half of the slice is the cave-floor rubble the stalagmite started growing on. Description from UA. Credit: Mari N. Jensen, UA College of Science]


Ref:  "Moisture Variability in the Southwestern U.S. Linked to Abrupt Glacial Climate Change," Nature Geoscience [in press]

[this post is taken in part from the UA news release]