VOLCANIC ERUPTIONS AND TREE-RINGS - ESTABLISHING CHRONOLOGICAL FRAMEWORKS FOR HUMAN AND ENVIRONMENTAL INTERACTION (Invited Presentation)

Volcanic eruptions have a diverse range of potential impacts for human societies. From localized destruction, to agricultural enhancement, to sudden, short term climatic perturbations and their associated consequences. Establishing a precise and accurate chronological anchor for the onset and duration of events is central to any investigation of these inter-relationships. The tree-ring record is particularly significant in this regard. Certain tree species reliably form rings of cells reflecting sub-annual to annual growth which can provide a range of data on the environmental conditions in which they were formed. These data may be extracted and explored in a variety of ways to link a specific, calendar dated growth ring with a volcanic event of uncertain age, and to measure the duration, extent or severity of climatic / environmental effects. The most well established application of this is in the correlation of anomalous tree-ring growth or cell formation (reflecting sudden onset climatic change) with layers of volcanic acidity / ash in ice core sequences. This combination of proxy records has proved most effective; however do tree-rings have even more to offer? This presentation will review landmark studies in volcano / tree-ring research to illustrate the diversity of possible approaches and problems. It will also explore the latest research in tree-ring chemistry as a means to further elucidate certain key volcanic events of the historic / prehistoric period.