GSA Annual Meeting in Indianapolis, Indiana, USA - 2018

Paper No. 17-1
Presentation Time: 8:05 AM

GSA QUATERNARY GEOLOGY AND GEOMORPHOLOGY DIVISION FAROUK EL-BAZ AWARD FOR DESERT RESEARCH: THE FUTURE IS AEOLIAN: CAN WE UNDERSTAND HOW DESERTS WILL RESPOND TO CLIMATE CHANGE FROM THEIR QUATERNARY HISTORY?


HESSE, Paul, Environmental Sciences, Macquarie University, Sydney, 2109, Australia

To answer this question we need to know not only the trajectory of climate change but also the sensitivity and response of desert aeolian processes to a changing climate. Mapping shows that, globally, most Quaternary dunefields are currently vegetated and largely stable. Further, dust fluxes measured from ice-cap and marine cores show Holocene levels much lower than in the past. Hence many desert areas are potentially susceptible to activation in the future. How well do we understand the processes by which stable desert dunes and dunefields become active? Or where or how desert dust is mobilised? Recent continental meta-analyses (Quaternary International, v410) showed, surprisingly, weak evidence to support the contention that, globally, desert dunefields were more active during the LGM. In comparison, there is widespread evidence that LGM dust fluxes were several times higher in many regions than today. If saltation bombardment is the primary mechanism for dust liberation then surely the two phenomena should be tightly correlated. These observations suggest that, in fact, there are important aspects of the desert aeolian system which we do not understand well. In this paper I will investigate evidence from Australia’s deserts of late Quaternary and contemporary responses of aeolian systems to climate change and variability.