Contact: Mari N. Jensen
University of Arizona
Caption: University of Arizona tree-ring researcher Daniel Griffin collects a core from the trunk of a ponderosa pine to study the tree's annual growth rings. He measures the width of such rings to study the monsoon rainfall history of the America Southwest.
Credit: (c) Scott St. George, University of Minnesota
Usage Restrictions: This image may only be used to accompany a story about the research described in the release, Monsoon Failure Key to Long Droughts in Southwest
Related news release: Monsoon failure key to long droughts in Southwest