Ice shelves, the floating extensions of the Antarctic Ice Sheet, are melted from below by the ocean. Increased ice shelf basal melting is the main mechanism by which Antarctica currently contributes to global sea level rise. As melt rates are sensitive to temperature, salinity, and circulation in tiny pockets of the Southern Ocean, predicting how they might respond to climate change is not straightforward. Projecting future ice shelf melting is at the forefront of coupled Earth system modelling, as most climate and ocean models still do not include ice shelves at all. This talk will summarise my research since 2020 on the future of ice shelf basal melting, focusing on three regions of Antarctica. In the Amundsen Sea, in West Antarctica, relatively warm ocean water already accesses the ice shelves. However, climate change is projected to make these regions warmer still, by increasing the volume of warm water flowing onshore. In contrast, Antarctica’s two largest ice shelves, the Ross and Filchner-Ronne, are currently bathed in cold water and melt rates are stable. However, numerous models predict that with sufficient climate change, these cavities could abruptly flip into a warm state similar to the Amundsen Sea. Sea level rise from Antarctica, therefore, is not all-or-nothing. Ice loss from some regions may already be committed, but in other regions abrupt changes may or may not be triggered, depending on how much the climate warms. Therefore, the trajectory of carbon emissions over the coming century will likely have a large impact on Antarctica’s long-term contribution to sea level rise.

How to cite: Naughten, K.: Ice shelves, the Southern Ocean, and the future, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-3134, https://doi.org/10.5194/egusphere-egu26-3134, 2026.

EGU26-3134

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Two centuries ago, the pioneers of modern empirical research revolutionized Earth science by treating nature as a dynamic, interconnected system—one best understood not through hypotheses alone, but through systematic observation and measurement. "Nature does not answer questions we have not yet asked," as Alexander von Humboldt observed, "it shows us phenomena we must first learn to see as questions."

Yet science today often prioritizes hypothesis-driven research, leaving little room for the unexpected. This lecture explores the tension between discovery and prediction in glaciology, where some of the transformations have emerged not from testing hypotheses, but from exploration, curiosity, and serendipity.

From overlooked data to phenomena no one anticipated, glaciology’s future depends on our willingness to reclaim discovery science—not as a replacement for hypothesis testing, but as its essential counterpart. As Aldous Huxley reminds us, "There are things known and things unknown, and in between are the doors of perception." To address todays and future challenges in Earth science, we must keep those doors open.

How to cite: Eisen, O.: Of Known Unknowns and Unobserved Knowns, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-2271, https://doi.org/10.5194/egusphere-egu26-2271, 2026.

EGU26-2271

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