The rapidly thinning Totten Glacier on the Sabrina Coast, East Antarctica, is the primary drainage outlet for ice within the Aurora Subglacial Basin, which could destabilize under the current atmospheric warming trend. There is growing need for direct geological evidence from the Sabrina Coast to frame late twentieth century Totten melting in the context of past warm climate analogs. Addressing this need, sediment archives were recovered from two sites on the Sabrina Coast slope and rise that record changes in terrigenous sedimentation and primary productivity in the region over glacial cycles since the mid‐Pleistocene transition (MPT). This research presents physical properties, grain size, diatom abundance and assemblages, and geochemical analysis from the two sites to determine how the processes that control sedimentation change between glacial and interglacial phases. The stratigraphic sequences in both cores record cyclic variations in physical properties and diatom abundances, which radiocarbon and biostratigraphic chronologies reveal as 100 Kyr glacial‐interglacial cyclicity. During glacials, terrigenous sediment deposition is enhanced by advanced grounded ice on the shelf, while primary productivity is restricted due to permanent summer sea ice extending past the continental slope. During interglacials, pelagic sedimentation suggests high surface productivity associated with contractions of regional sea ice cover. Comparison with post‐MPT slope records from Wilkes Land and the Amundsen Sea shows that this pattern is consistent in slope sediments around the margin. The higher‐amplitude variations in Antarctic ice volume and sea ice extent post‐MPT ensure that these signals are pervasive around the Antarctic margin.

中文翻译：

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自更新世中期以来，对南极东部托滕冰川的沉积和初级生产力下坡的控制

南极东部萨布丽娜海岸快速变薄的托滕冰川是奥罗拉冰河盆地内冰的主要排水出口，在当前的大气变暖趋势下，冰可能会不稳定。从萨布丽娜海岸（Sabrina Coast）获取直接的地质证据，以构筑二十世纪后期的托特融化（在过去温暖的气候类似物的背景下）的需求日益增长。为满足这一需求，从中更新世过渡期（MPT）以来，从萨布丽娜海岸斜坡的两个地点恢复了沉积物档案，并记录了冰川周期中该地区陆相沉积和初级生产力的变化。这项研究提出了物理性质，晶粒尺寸，硅藻丰度和组合物，并从这两个地点进行地球化学分析，以确定控制沉积的过程在冰期和冰间期之间如何变化。两个岩心中的地层层序记录了物理性质和硅藻丰度的周期性变化，放射性碳和生物地层年代学显示为100 Kyr冰川间冰期。在冰川时期，陆架上先进的地面冰层增加了陆源性沉积物的沉积，而永久性夏季海冰越过大陆斜坡，限制了初级生产力。在间冰期，上层沉积表明与区域海冰覆盖收缩有关的高地表生产力。与来自Wilkes Land和Amundsen Sea的MPT后斜坡记录的比较表明，这种模式在边缘附近的斜坡沉积物中是一致的。MPT后南极冰量和海冰范围的较大幅度变化确保了这些信号在南极边缘周围普遍存在。