Opposite Dust Grain Size Patterns in the Pacific and Atlantic Sectors of the Southern Ocean During the Last 260,000 Years


Contact
michelle.van.der.does [ at ] awi.de

Abstract

Southern Ocean westerly wind intensity and position are thought to play a crucial role in controlling glacial/interglacial CO2 changes through their impact on Antarctic upwelling intensity and the delivery of iron-rich dust that stimulates biological production during glacial periods. Sediment-core grain size records can provide key insights into changes in wind strength and source-area characteristics over glacial-interglacial timescales. However, so far, little is known about G/IG grain size changes in Southern Ocean sediments. For this study, we analyzed the grain-size distributions of two subantarctic deep sea sediments cores from the Pacific (PS75/056-1) and Atlantic (ODP Site 1090) sectors of the Southern Ocean. Dust mean grain size shows opposing trends in the two Southern Ocean sectors. Coarser glacial grain sizes are observed in the Pacific sector, while finer glacial grain-sizes are observed in the Atlantic. Our results suggest that changes in the latitudinal position of the SWW had distinct impacts on grain size distribution in the Atlantic and Pacific sectors, also likely associated with shifts in the dust source areas. These findings indicate that more extensive studies of grain-size distribution in the Southern Ocean can provide important insights on the timing and latitudinal extent of the westerly winds changes during ice ages.



Item Type
Conference (Invited talk)
Authors
Divisions
Primary Division
Programs
Primary Topic
Peer revision
Not peer-reviewed
Publication Status
Published
Event Details
AGU Fall Meeting 2020, 01 Dec 2020 - 01 Dec 2020, Online (virtual meeting).
Eprint ID
53465
Cite as
van der Does, M. , Wengler, M. , Lamy, F. , Martinez-Garcia, A. , Kuhn, G. , Stuut, J. B. , Tiedemann, R. and Winckler, G. (2020): Opposite Dust Grain Size Patterns in the Pacific and Atlantic Sectors of the Southern Ocean During the Last 260,000 Years , AGU Fall Meeting 2020, Online (virtual meeting), December 2020 - December 2020 .


Share

Research Platforms

Campaigns


Actions
Edit Item Edit Item