Processes occurring at the grounding zone of marine terminating ice streams are crucial to marginal stability, influencing ice discharge over the grounding-line, and thereby regulating ice-sheet mass balance. We present new marine geophysical data sets over a ~30940 km area from a former ice-stream grounding zone in Storfjordrenna, a large cross-shelf trough in the western Barents Sea, south of Svalbard. Mapped ice-marginal landforms on the outer shelf include a large accumulation of grounding-zone deposits and a diverse population of iceberg ploughmarks. Published minimum ages of deglaciation in this region indicate that the deposits relate to the deglaciation of the Late Weichselian Storfjordrenna Ice Stream, a major outlet of the Barents Sea–Svalbard Ice Sheet. Sea-floor geomorphology records initial ice-stream retreat from the continental shelf break, and subsequent stabilization of the ice margin in outer-Storfjordrenna. Clustering of distinct iceberg ploughmark sets suggests locally diverse controls on iceberg calving, producing multi-keeled, tabular icebergs at the southern sector of the former ice margin, and deep-drafted, single-keeled icebergs in the northern sector. Retreat of the palaeo-ice stream from the continental shelf break was characterized by ice-margin break-up via large calving events, evidenced by intensive iceberg scouring on the outer shelf. The retreating ice margin stabilized in outer-Storfjordrenna, where the southern tip of Spitsbergen and underlying bedrock ridges provide lateral and basal pinning points. Ice-proximal fans on the western flank of the grounding-zone deposits document subglacial meltwater conduit and meltwater plume activity at the ice margin during deglaciation. Along the length of the former ice margin, key environmental parameters probably impacted ice-margin stability and grounding-zone deposition, and should be taken into consideration when reconstructing recent changes or predicting future changes to the margins of modern ice streams.

中文翻译：

---

巴伦支海西部 Storfjordrenna 冰流初始冰消期的冰缘退缩和接地带动力学

在海洋终止冰流的接地区发生的过程对于边缘稳定性至关重要，影响着接地线上的冰排放，从而调节冰盖质量平衡。我们提供了来自 Storfjordrenna 的前冰流接地区约 30940 公里区域的新海洋地球物理数据集，Storfjordrenna 是斯瓦尔巴群岛南部巴伦支海西部的一个大型跨大陆架槽。外陆架上绘制的冰缘地貌包括大量的接地带沉积物和多样化的冰山犁痕。该地区已公布的最小冰川消退年龄表明，这些沉积物与晚魏克瑟尔期 Storfjordrenna 冰流的消冰作用有关，后者是巴伦支海-斯瓦尔巴冰盖的主要出口。海底地貌记录了最初的冰流从大陆架断裂处撤退，以及随后外斯托夫约德雷纳冰缘的稳定。不同冰山犁痕集的聚集表明对冰山崩解的局部控制不同，在前冰缘的南段产生多龙骨板状冰山，在北段产生深水单龙骨冰山。古冰流从大陆架断裂处撤退的特点是冰缘因大型崩解事件而破裂，外大陆架上的冰山强烈冲刷证明了这一点。退缩的冰缘在外 Storfjordrenna 稳定下来，斯匹次卑尔根岛的南端和下面的基岩山脊提供了侧向和基底钉扎点。接地带沉积物西侧的近冰扇记录了冰川消融期间冰下融水管道和冰缘融水羽流活动。沿着前冰缘的长度，关键环境参数可能影响冰缘稳定性和接地带沉积，在重建现代冰流边缘的近期变化或预测未来变化时应予以考虑。