Australian Antarctic scientists are part of a bold international plan to target the knowledge gaps that prevent reliable predictions about future sea-level rise.
Image Credit: Felicity McCormack, Securing Antartica's Environmental Future
A new community-led scientific review proposes geophysical surveys of the entire Antarctic coastal region with three circumpolar rings around the icy continent.
The study, recently published in American Geophysical Union (AGU)’s Reviews of Geophysics, synthesizes current understanding of how ice, ocean, atmosphere and the solid Earth interact in Antarctica’s coastal zone, and highlights key knowledge gaps and the need for improved observations at a pan-Antarctic scale.
“Scientists would run three continent-wide survey rings around Antarctica – tracking inland ice flow, grounding zones and ocean-facing ice shelves to capture the critical processes driving ice loss,” said one of the study’s lead authors, Dr Felicity McCormack, a Chief Investigator at Securing Antarctica’s Environmental Future (SAEF), based at Monash University.
“This ambitious, globally coordinated campaign would resolve the biggest uncertainties in predicting Antarctic sea-level rise, with huge implications for coastal planning and efforts to support low-lying nations, including Australia’s Pacific neighbors.”
“The plan would transform our understanding of the Antarctic coastal system to reveal how far and how fast Antarctic ice loss could redraw coastlines around the world,” said study co-author Dr Chen Zhao, a Chief Investigator at the Australian Centre for Excellence in Antarctic Science (ACEAS) and ice–ocean systems analyst with the Australian Antarctic Program Partnership, based at the University of Tasmania.
The review was written by 80 scientists across 16 countries, spanning glaciology, oceanography, geophysics, and atmospheric science, coordinated through the Scientific Committee on Antarctic Research (SCAR) RINGS Action Group. RINGS is also endorsed by the Council of Managers of National Antarctic Programs (COMNAP), which provides logistics knowledge for efficient survey planning and better coordination between national Antarctic programs.
The paper brings together existing observations, models, and theory to highlight how incomplete data continue to limit estimates of Antarctic ice loss and future sea-level rise.
A Critical Control Point for Sea-Level Rise
The Antarctic coastal zone is not simply the edge of the continent. It is a tightly coupled system where grounded ice meets the ocean, and where small changes can have outsized consequences. Processes occurring near the grounding zone – the point where ice lifts off the bed and begins to float – can regulate ice discharge or, under certain conditions, trigger feedbacks that accelerate ice loss.
Observations over recent decades show that Antarctic mass loss has increased. The most rapid changes are driven by interactions between the ice and surrounding ocean, and by ice flow at the margins of the ice sheet, rather than surface melting alone. Yet key coastal conditions remain poorly mapped.
The Biggest Gaps – And Why They Matter
The review identifies persistent gaps in direct observations of coastal bed topography and sub-ice shelf cavities. Because ice sheet models are highly sensitive to conditions at the coast, even advanced models can produce misleading results when these data are missing or poorly constrained.
While satellite observations provide powerful measurements of ice motion and surface change, they cannot observe the bedrock under the ice from space. Australia has played a leading role in international efforts to map the Antarctic bedrock, most notably through the ICECAP airborne geophysics program, which has produced some of the most detailed bed-topography measurements of the East Antarctic margin to date.
“Mapping the land and seafloor under Antarctica’s ice and ice shelves is critical to accurately predict the continent’s contribution to future sea-level rise, which is currently the largest source of uncertainty in sea-level projections as the climate changes,” said Dr McCormack.
“It’s time to invest more in emerging technologies that can do this, such as autonomous aerial vehicles and next-generation ice-penetrating radar, to address one of the most critical challenges facing humanity.”
A Roadmap for Coordinated Action
Because no single nation can achieve comprehensive coverage alone, the authors emphasize that international coordination is essential.
“Uncoordinated surveys risk leaving gaps or duplicating effort. This paper provides an evidence-based framework to support coordinating RINGS activities under SCAR and COMNAP, helping to build more comprehensive datasets for improved sea-level projections,” said first author and the chair of the RINGS Action Group, Dr Kenichi Matsuoka at Norwegian Polar Institute.
“Such internationally coordinated efforts can serve as a stepping stone towards the next International Polar Year 2032–33,” Dr Matsuoka concluded.