Daniel Griffin, University of Minnesota (IMAGE)
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
License
Licensed content