Topographic variability beneath ice sheets regulates ice flow, basal melting, refreezing processes, and meltwater drainage. The preservation of old ice layers and basal ice stratigraphy is sensitive to these subglacial processes, and Dome Fuji, inland East Antarctica, is one of the few regions where 1.5-Ma old ice can be preserved for investigating a major climatic change that occurred in the mid-Pleistocene. We used stochastic simulation methods and radar data to generate an ensemble of simulated bed topography with the continuous and realistic roughness necessary to assess basal conditions. Ensemble analysis reveals the magnitude and spatial distribution of topographic uncertainty, facilitating uncertainty-constrained assessments of subglacial drainage and topographic adjustments to geothermal heat flow (GHF). We find that topographic variability can lead to widespread local GHF variations of ±20% of the background value, which aggregate to raise the regional value and suggest previously underestimated distributions and rates of basal melting. We also find that survey profile spacing has an increasing influence on topographic uncertainty for rougher bed, deriving an empirical relationship that could guide future survey planning based on uncertainty tolerance.

中文翻译：

---

地床地形的随机模拟限制了南极洲东部富士山附近的地热热流和冰下排水

冰盖下方的地形变化调节冰流、基底融化、再冻结过程和融水排水。老冰层和基底冰地层的保存对这些冰下过程很敏感，南极洲东部内陆的圆顶富士是少数可以保存 1.5 Ma 老冰的地区之一，用于研究南极洲发生的重大气候变化。更新世中期。我们使用随机模拟方法和雷达数据来生成模拟床地形的集合，其具有评估基础条件所需的连续且真实的粗糙度。集合分析揭示了地形不确定性的大小和空间分布，有助于对冰下排水的不确定性约束评估和地热热流（GHF）的地形调整。我们发现，地形变异性可能导致广泛的局部 GHF 变化，范围为背景值的 ±20%，这些变化加在一起会提高区域值，并表明先前低估的基底融化的分布和速率。我们还发现，测量剖面间距对粗糙床的地形不确定性的影响越来越大，得出了一种经验关系，可以指导基于不确定性容忍度的未来测量规划。