A glaciochemical study of the 120 m ice core from Mill Island, East Antarctica

Mana Inoue*, Mark A. J. Curran, Andrew D. Moy, Tas D. van Ommen, Alexander D. Fraser, Helen E. Phillips, Ian D. Goodwin

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)
11 Downloads (Pure)

Abstract

A 120 m ice core was drilled on Mill Island, East Antarctica (65°30′ S, 100°40′E) during the 2009/2010 Australian Antarctic field season. Contiguous discrete 5cm samples were measured for hydrogen peroxide, water stable isotopes, and trace ion chemistry. The ice core was annually dated using a combination of chemical species and water stable isotopes. The Mill Island ice core preserves a climate record covering 97 years from 1913 to 2009CE, with a mean snow accumulation of 1.35m (ice-equivalent) per year (mIEyr-1). This northernmost East Antarctic coastal ice core site displays trace ion concentrations that are generally higher than other Antarctic ice core sites (e.g. mean sodium levels were 254 μEq L-1). The trace ion record at Mill Island is characterised by a unique and complex chemistry record with three distinct regimes identified. The trace ion record in regime A displays clear seasonality from 2000 to 2009 CE; regime B displays elevated concentrations with no seasonality from 1934 to 2000 CE; and regime C displays relatively low concentrations with seasonality from 1913 to 1934 CE. Sea salts were compared with instrumental data, including atmospheric models and satellite-derived sea-ice concentration, to investigate influences on the Mill Island ice core record. The mean annual sea salt record does not correlate with wind speed. Instead, sea-ice concentration to the east of Mill Island likely influences the annual mean sea salt record. A mechanism involving formation of frost flowers on sea ice is proposed to explain the extremely high sea salt concentration. The Mill Island ice core records are unexpectedly complex, with strong modulation of the trace chemistry on long timescales.

Original languageEnglish
Pages (from-to)437-453
Number of pages17
JournalClimate of the Past
Volume13
Issue number5
DOIs
Publication statusPublished - 9 May 2017

Bibliographical note

Copyright the Author(s) 2017. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.

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