Dry lake beds as sources of dust in Australia during the Late Quaternary: A volumetric approach based on lake bed and deflated dune volumes. (1st April 2017)

• Record Type: Journal Article
• Authors: Farebrother, Will; Hesse, Paul P.; Chang, Hsing-Chung; Jones, Claudia
• Is Part Of: Quaternary science reviews. Volume 161(2017)
• Page Start: 81
• Page End: 98
• Publication Date: 2017-04-01
• Subjects: Dust -- Quaternary -- South Pacific -- DEM -- Aeolian; Geology, Stratigraphic -- Quaternary -- Periodicals; Stratigraphie -- Quaternaire -- Périodiques; 551.79
• DOI: 10.1016/j.quascirev.2017.02.019
• Languages: English
• ISSNs: 0277-3791

Abstract

Abstract: Dust affects Earth's climate, ecology and economies across a broad range of scales, both temporally and spatially, and is an integral part of the earth's climate system. Previous studies have highlighted the importance of inland lake beds to dust emissions both locally and globally. This study aims to explore the relative volumetric importance of ephemeral lakes that emit dust to the Australian southeastern dust path over the last glacial cycle. SRTM DEMs and GIS analyses of long-term (up to 80 ka) lake-bed deflation volumes and deposition of sand-sized sediment onto downwind source bordering dunes were used to derive estimates of transported dust mass. A strong power relationship was found between lake area and the mass of deflated lake bed sediments. Total dust masses for the largest 53 lakes in southeastern Australia were derived using the relationship between lake area and dust mass and used to determine an upper value for total dust mass deflated from lake beds in southeastern Australia. Ephemeral lake-derived dust was found to represent at most 13% of the dust derived from southeastern Australia deposited in the southern Pacific over the last 80 ka or 22% over the last 40 ka. Lake Eyre (the largest lake) has contributed at most 3% of the Australian southeast dust plume. These results imply that there are significant additional sources of dust in Australia over these timescales, such as floodplains or dunefields, and that modelling must allow for diverse climatic and geomorphic controls on dust production. Highlights: Deflationary lake basins in Australia were examined for their Late Quaternary dust flux. Basin volumes from SRTM DEM minus volume of source-bordering dunes yields volume of dust. Total dust yield from SE Australian lakes is 13–22% of Australian dust in SW Pacific. Multiple geomorphic sources, with different processes, contribute to continental dust flux.