Science at the Shine Dome 2010

Career research awards

Thursday, 6 May 2010

2010 Mawson Medal and Lecture

Patrick De Deckker
Associate Director, Earth Environment Group Leader, Research School of Earth Sciences
Australian National University

Patrick De Deckker did a PhD in the Zoology Department at the University of Adelaide on salt lakes, their biota and Quaternary lacustrine deposits. He continued in this field during seven years of postdoctoral positions. He obtained a DSc from the same university, from the Department of Geology and Geophysics, for long-term accomplishment in the fields of limnology, palaeolimnology, palaeoceanography and micropalaeontology. In 1988, Patrick joined the Australian National University and has held a full-time teaching position combined with research ever since. He led the informal Australian Marine Quaternary Program that brought together many people working on many aspects of marine science and deep-sea cores. During his entire career, Patrick’s work has always been multidisciplinary in nature with a common aim: to obtain information of relevance for the reconstruction of past marine and continental environments of importance for the understanding of global and regional climatic variability.

Geochemical and microbiological fingerprinting of Australian airborne dust

Understanding the origin and composition of Australian dust has implications for the environment, the oceans and human health. However, there is scant published information on the chemical and biological composition of airborne dust in Australia.
My talk will concentrate on an intensive, multidisciplinary and collaborative analysis of dust from the 22 October 2002 Canberra dust storm event, as well as for several events that occurred in September 2009. The latter significantly affected Sydney and a large portion of the east coast of Australia. These dust events were investigated using a variety of approaches, including DNA microbiology, organic and inorganic chemistry, palynology, sedimentology, mineralogy, meteorology and satellite imagery.

Using a variety of geochemical and palynological 'fingerprinting' analyses, including investigations of Nd and Sr isotopes, the provenance of the dust that rained down in Canberra on these occasions is linked to parts of western NSW and central Australia, respectively. Investigation of the meteorological events at these times corroborates the results. Further investigations using different isotopes of Nd, Pb and Sr demonstrate that Australian dust has clearly been linked, for particular episodes of the Late Quaternary, to dust recovered from Antarctic ice cores.

This project has involved numerous investigators from Australia and overseas and was funded by an Australian Research Council Discovery grant.