MSc in Geography
Reconstruction of Late-Glacial Environmental and Climate Change, Mavora Lakes, New Zealand
Assoc. Prof. Sean Fitzsimons
The late-glacial period (ca. 18-10 kyr BP) was characterised by a series of abrupt climate changes, registered in paleoclimate records throughout the North Atlantic region. One such event was first identified in terrestrial proxy records from Northern Europe by an increase in cold climate flora, most notably Dryas octopetala, indicating a return to colder conditions. The event is locally identified throughout the North Atlantic region as the Younger Dryas Staidal and is dated between c. 11,000 and 10,000 14C yr BP. The degree to which these abrupt climate changes are reflected in paleoclimate records from the Southern Hemisphere is, however, far from evident. Although there is a growing body of evidence that suggests rapid environmental changes have occurred in the Southern Hemisphere during the late-glacial, it remains to be determined whether these changes are a direct result of climate cooling in the Northern Hemisphere. In New Zealand, most evidence of Quaternary climate change is preserved in records of glacier activity and vegetation change. Glacier advances, recorded mainly in the South Island of New Zealand provide evidence of late glacial climate change but often lack precise dating. Evidence for late-glacial abrupt climate anomalies in New Zealand remains uncertain because there are few records which span the late-glacial, few record rapid climate changes, and most records are characterised by poor chronological and analytical resolution. The strategy that is to be used in this investigation is different in that it is an integrative, multi-proxy approach combining pollen records and glacier evidence together to provide a comprehensive reconstruction of environmental change. The principal aims of this study are to undertake a high resolution palynological investigation of late glacial peat sequences from the Mavora Lakes area, to reconstruct the vegetation and climate history of the region in conjunction with a detailed mapping and dating investigation of glacial landforms in order to produce a comprehensive picture of late glacial environmental change and to test proposed mechanisms of global climate change. The outcomes of this project are expected to further develop the understanding of inter-hemispheric climate relationships and to test the proposed mechanisms of global climate change. It will also provide further evidence characterising the late-glacial climate in New Zealand, which in conjunction with previous research will allow for a robust chronology of climatic events to be developed for southern New Zealand.