An Isotopic Map of Dust Source Areas in the McMurdo Sound Sector of Antarctica

• Main Authors: Blakowski M. A., Aciego S., Delmonte B., BARONI, CARLO, SALVATORE, MARIA CRISTINA
• Other Authors: AGU, Blakowski, M. A., Aciego, S., Delmonte, B., Baroni, Carlo, Salvatore, MARIA CRISTINA
• Format: Conference Object
• Language: English
• Published: American Geophysical Union 2014
• Subjects: Aeolian dust; Geomorphological survey; Isotopic map; Victoria Land; Antarctica; Antarctic; The Antarctic; McMurdo Sound; McMurdo Ice Shelf; Royds; Cape Royds; Cape Bird; Royds Cape; Antarc*; Ice Sheet; Ice Shelf; polar desert; Sea ice
• Online Access: http://hdl.handle.net/11568/646074

The McMurdo Sound sector of Antarctica features a unique, polar desert ecosystem characterized by low temperatures, hyper-aridity, and high-speed winds. These climatic conditions result in limited water sources, sparse vegetation, underdeveloped soils, and abundant unconsolidated sediment easily influenced by wind-driven transport. Radiogenic isotopes (87Sr/86Sr, 143Nd/144Nd) provide constant signatures of dust from source- to sink-areas. Accordingly, aeolian dust derived from arid regions has been recognized in many studies as an important tracer of atmospheric circulation, as well as a tool for deciphering past climatic conditions in dust source regions. However, while major global dust sources (e.g. from South America, Africa, and Asia) are well studied and easily identifiable via distinct isotopic signatures when encountered in different depositional environments (e.g. Antarctic ice cores), local material from sources in and around the ice-free Dry Valleys and surrounding areas have remained in need of further documentation. We analyzed 40 samples of silt, sand, glacial drift, and weathered regolith material in both fine (<5μm) and coarse fractions collected from Victoria Land and the McMurdo Sound sector, including Cape Royds, Cape Bird, and the McMurdo Ice Shelf. Here we present an ArcGIS-generated, high-precision geochemical map of Antarctic PSAs synthesized from our data and combined with geomorphological and stratigraphic information on the studied sites. We believe that our expanded isotopic catalogue and map can be used to enhance and/or prompt regional studies in a variety of disciplines, such as by providing greater constraints on models of regional dust variability and transport pathways and of the melting history of the Antarctic ice sheet, and by determining the provenance of dust archived in ice cores, lake sediment, soil records, and impurities in Antarctic sea-ice.