Transient ice sheet response of the Antarctic Ice Sheet during the Last Interglacial - Wilkes Basin collapse scenarios

The response of the East Antarctic Ice Sheet to global warming represents a major source of uncertainty in sea level projections. Thinning of the East Antarctic George V and Sabrina Coast ice-cover is currently taking place, and regional ice-sheet instability episodes might have been triggered in past warm climates. However, the magnitude of ice retreat in the past can not yet be quantitatively derived from paleo-proxy records alone. We propose that a runaway retreat of the George V coast grounding line and subsequent instability of the Wilkes Basin ice-sheet would either leave a clear imprint on the water isotope composition in the Talos Dome region or prohibit a Talos Dome ice-core record from the Last Interglacial altogether. Testing this hypothesis our ice sheet model simulations suggest, that Wilkes Basin ice-sheet retreat remained relatively limited during the Last Interglacial and provide a constraint on Last Interglacial East Antarctic grounding line stability.

东南极冰盖（East Antarctic Ice Sheet）对全球变暖的响应，是海平面预测领域不确定性的主要来源之一。当前，东南极乔治五世海岸与萨布丽娜海岸的冰盖正发生减薄，且区域冰盖失稳事件可能在过往温暖气候时期就已被触发。然而，仅凭古代用指标记录（paleo-proxy records），目前尚无法仅通过该类记录定量反演过去的冰退规模。我们提出，乔治五世海岸接地线（grounding line）的失控崩退以及随后发生的威尔克斯盆地（Wilkes Basin）冰盖失稳，要么会在塔尔穹顶（Talos Dome）区域的水体同位素组成中留下清晰的印记，要么会完全抹去末次间冰期（Last Interglacial）的塔尔穹顶冰芯记录。通过冰盖模式（ice sheet model）模拟对该假说进行检验后，结果表明：末次间冰期期间，威尔克斯盆地冰盖的崩退规模相对有限，且该结果可为末次间冰期东南极冰盖接地线的稳定性提供约束条件。