TUCSON, Arizona, May 3 (TNSJou) -- The University of Arizona issued the following news release: * * * Tree-ring, ice core and volcano experts teamed up to identify one of the most climatically impactful volcanic eruptions in 4,000 years - Aniakchak II. In the process, they narrowed down potential dates for the Thera volcano eruption. * * * A University of Arizona tree-ring expert is closer than ever to pinning down the date of the infamous Thera volcano eruption - a goal she has pursued for   more