Rift Propagation for Ice Sheet Models

Modelled projections of the contribution of the Antarctic ice sheets to sea level rise over this century vary from a few centimetres to more than one metre - a huge uncertainty which undermines the credibility of sea level rise projections. The reasons for this uncertainty lie in the treatment of ice shelves - the floating extensions of ice sheets which constrain the flow of ice from the interior to the ocean. Assuming that ice shelves will disintegrate leads to a much higher estimate of ice discharge than assuming they remain in place. No forecast so far, however, has included the processes of ice fracture and rift propagation that lead to ice shelf disintegration. These processes disrupt the normal assumptions of continuity inherent in ice sheet models and are highly dependent on the heterogeneous nature of ice shelves. We will overcome this fundamental limitation in sea level rise projections by explicitly representing heterogeneity in ice shelves and pioneering the inclusion of rift processes in an ice sheet model. We will meet these challenges by collecting new field and satellite data to quantify ice shelf heterogeneity and developing a fracture physics approach to simulate rift propagation. RIPFISH will enable a new generation of ice sheet models to achieve a step-change improvement in quantifying and reducing uncertainties in sea level rise projections.

BENEFICIARIES OF THIS RESEARCH AND HOW THE IMPACT WILL BE REALISED
RIPFISH will benefit:
1) Government advisors and policymakers, through more comprehensive assessment of the future of the Antarctic ice sheets that is less reliant than at present on assumptions about the break-up of Antarctic ice shelves.
WHO: Climate change advisers and influencers.
MEANS OF COMMUNICATION: Personal networks and Project Partners (e.g. BAS).
OUTPUTS AND ACTIVITIES: Research briefings, e.g. Parliamentary Office of Science and Technology POST-Notes.

2) Teachers, and students of all ages, through engaging targeted outreach about ice shelves, their significance in Antarctic mass balance, the importance of rift propagation, and the role of suture zones in allowing ice shelves to grow to the size we see them today.
WHO: The education sector by targeted engagement.
MEANS OF COMMUNICATION: Online science platforms and public engagement events.
OUTPUTS AND ACTIVITIES: Time for Geography schools' video, bespoke web page, schools talks, Swansea Science Festival, Oriel Science exhibition.

3) The wider public, through social media and web page generation to engage and inspire the public in cryospheric issues and ice shelves in particular, focussing on field activities, satellite data animations and the broader impact of changes occurring in Antarctica.
WHO: Broad public interest.
MEANS OF COMMUNICATION: Social media, in-person and online public engagement.
OUTPUTS AND ACTIVITIES: Swansea Science Story with Lizzie Daly (Swansea's outreach fellow BBC broadcaster), invited talks by Project Investigators.

4) The academic community, through the generation of model code that can be incorporated in ice sheet simulations to allow the simulation of ice shelf fractures, and new measurements describing the heterogeneity of ice shelves and the structure of suture zones.
WHO: Glaciologists and other scientists.
MEANS OF COMMUNICATION: Peer-reviewed literature.
OUTPUTS AND ACTIVITIES: High impact papers and conference presentations.