EGU25-15088, updated on 15 Mar 2025
https://doi.org/10.5194/egusphere-egu25-15088
EGU General Assembly 2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
An assessment of modern and past Circumpolar Deep Water presence beneath Shackleton Ice Shelf, East Antarctica: insights into using Meteoric Beryllium-10
Matthew Jeromson1, Molly Husdell2, Helen Bostock2, David Fink3, Krista Simon3, Ole Rieke4, Sarah Thompson4, Madi Rosevear4, Luke Nothdurft5, Laura Herraiz–Borreguero6, and Duanne White1
Matthew Jeromson et al.
  • 1Australian Centre for Excellence in Antarctic Science, University of Canberra, BRUCE, Australia (m.jeromson@gmail.com)
  • 2University of Queensland, Brisbane, Australia
  • 3Australian Nuclear Science and Technology Organisation (ANSTO), Sydney, Australia
  • 4University of Tasmania, Hobart, Australia
  • 5Queensland Institute of Technology, Brisbane, Australia
  • 6Commonwealth Scientific and Industrial Research Organisation (CSIRO), Hobart, Australia

Perched precariously upon the deepest continental location on Earth, East Antarctica’s Denman Glacier is hypersensitive to changes in both air and ocean temperatures. Shackleton Ice Shelf buttresses Denman Glacier, regulating the rate at which it flows into the Southern Ocean. However, under warming ocean conditions along the continental shelf – a function of increased upwelling of warm Circumpolar Deep Water (CDW) in many places around Antarctica – Shackleton Ice Shelf may become unstable and collapse. Loss of the ice shelf would destabilise the glacier in turn, and a complete collapse of the Denman System could contribute +1.5 m to global sea level. Besides what began 15 years ago, observational ocean data show that the interactions between upwelling CDW and regional calving margins is otherwise unprecedented in historical records, and of unknown influence on longer timescales. Here we aim to resolve two questions: is warm CDW currently reaching the glacier’s grounding line? And is there any evidence of CDW presence within the Shackleton Ice Shelf on a Holocene timescale? Utilising a Conductivity-Temperature-Depth (CTD) profile and a 1m sediment core collected from the seafloor beneath Shackleton Ice Shelf during the 2023-24 Denman Terrestrial Campaign, we employ meteoric-10Be signatures from sediment samples – which have been shown to reflect upwelling circumpolar deep-water conditions along the Antarctic continental shelf – to discuss the modern and paleo-ocean conditions within the Shackleton Ice Shelf cavity.

How to cite: Jeromson, M., Husdell, M., Bostock, H., Fink, D., Simon, K., Rieke, O., Thompson, S., Rosevear, M., Nothdurft, L., Herraiz–Borreguero, L., and White, D.: An assessment of modern and past Circumpolar Deep Water presence beneath Shackleton Ice Shelf, East Antarctica: insights into using Meteoric Beryllium-10, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15088, https://doi.org/10.5194/egusphere-egu25-15088, 2025.