Beryllium isotope signatures of ice shelves and sub-ice shelf circulation

Be isotopes are a useful tracer of sediment source and transport pathways but have not been widely tested in glacio-marine environments. We measured Be isotopes in a range of depositional environments from open marine, sub-ice shelf and subglacial settings throughout Prydz Bay, one of Antarctica's largest ice drainage systems. We find that strong sub-ice shelf and bottom current circulations can advect 10Be-rich open marine sediments into an ice shelf cavity, and 10Be-poor terrestrial sediments onto the continental shelf at the ice shelf outflow, meaning that 10Be concentrations reflect sub-ice shelf circulation patterns rather than depositional environment. However, HCl-extractable 10Be/9Be ratios can provide a more robust discrimination of sediment deposited in open marine and sub-ice shelf settings. Thus, Be isotopes are a useful tracer of both environmental setting and sub-ice shelf circulation strength in both modern and paleo-ice sheet margins. Crown Copyright © 2018 Published by Elsevier B.V.

Keywords

Ice, Beryllium 10, Isotopes, Sediments, Antarctica, Advection

Citation

White, D. A., Fink, D., Post, A. L., Simon, K., Galton-Fenzi, B., Foster, S., Fujioka, T., Jeromson, M. R., Blaxell, M., Yokoyama, Y. (2019). Beryllium isotope signatures of ice shelves and sub-ice shelf circulation. Earth and Planetary Science Letters, 505, 86-95, doi:10.1016/j.epsl.2018.10.004

URI

https://doi.org/10.1016/j.epsl.2018.10.004
https://apo.ansto.gov.au/dspace/handle/10238/12507

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