ANSTO Access Proposal AP19482: For how long have warm waters been interacting with the grounding line of Denman Glacier?

In this project we aim to apply beryllium isotopes as a proxy for CDW upwelling in the Denman Region of Antarctica. We will use temporal and spatial shifts in the 10Be/9Be ratio in sediments from the open marine environment and from beneath Shackleton Ice Shelf. These samples have been recently collected during the Australian Denman Terrestrial Campaign (2023-2024) and the German “EASI-3” campaign (2024) to establish for how much of the Holocene warm CDW has been accessing the Denman Region’s Continental Shelf and the Shackleton Ice Shelf cavity. Our group has successfully developed the 10Be/9Be proxy for this application through use of a spatial dataset across multiple Antarctic marine systems (Jeromson et al 2024a, Jeromson et al 2024b, Jeromson et al in review). Something we also aim to advance further through the prospective data from this project.
We have four key objectives to resolve this aim:
1. Produce a robust age model for the core collected from beneath the Shackleton Ice Shelf (EBD-01b) by using relative (e.g. diatom assemblage change) and absolute (e.g. stepwise combustion 14C) dating techniques.
2. Confirm the application of the beryllium isotope proxy in Denman Marine region sediments by measuring a set of spatial samples (as per Jeromson et al 2024).
3. Measure EBD-01B and a transect of 3 to 4 cores from the open marine setting for Beryllium isotopes at a resolution of 200 to 500 years through the Holocene to map the incursion of CDW onto the continental shelf.
4. Conduct a set of complementary proxy analyses to get a more complete picture of processes acting on the continental shelf and within the ice shelf cavity.
Access to 10Be and 14C preparation and measurement are requested from ANSTO to complete these objectives.