Direct evidence of aeolian deposition of marine diatoms to an ice sheet

• Published in: Antarctic Science
• Main Authors: Budgeon, A.L., Roberts, D., Gasparon, M., Adams, N.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2012
• Subjects: Antarc*; Antarctic; Antarctic Science; Antarctica; East Antarctica; Ice Sheet; Sea ice; Windmill Islands
• Online Access: http://dx.doi.org/10.1017/s0954102012000235; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102012000235

Abstract Antarctic snow samples collected from the Wilkins Runway, c. 50 km inland from the Windmill Islands, East Antarctica, contain aeolian-derived diatoms. The diatom assemblage preserved is exclusively of marine origin. As diatoms are excellent indicators of source conditions, we are able to confirm that an unusual weather event, with anomalous north-westerly winds blowing at around 10 m s -1 , resulted in the deposition of coastal marine species at the Wilkins Runway. The composition of the floral assemblage collected indicate that the parent water mass was from a coastal marine region undergoing typical Antarctic summer conditions with periods of both consolidated sea ice and open water. On inspection of available satellite imagery, these conditions were found upwind of the deposition site. This study provides a methodology for diatoms found within ice cores to be identified and the source region to be determined. It also provides evidence for a large-scale aeolian deposition of marine diatoms to an ice sheet, which may have implications for the interpretation of controversial marine diatoms found in sediments that have been used as evidence for the retreat of the East Antarctic Ice Sheet.