Abstract Autonomous Underwater Vehicles (AUVs) deployed close to the seafloor can acquire high-resolution geophysical data about the topography and shallow stratigraphy of the seabed, yet have had limited application within the fields of glacial geomorphology and ice sheet reconstruction. Here, we present multibeam echo-sounding, side-scan sonar, sub-bottom profiler and High-Resolution Synthetic Aperture Sonar (HISAS) data acquired during three AUV dives on the northeast Antarctic Peninsula continental shelf. These data enable glacial landforms, including mega-scale glacial lineations (MSGLs), grounding-zone wedges (GZWs) and iceberg ploughmarks, to be imaged at a horizontal resolution of a few tens of centimetres, allowing for the identification of subtle morphological features. We map tidal ridges that are interpreted as having been formed 1) along the ice-sheet grounding line by the squeezing up of soft seafloor sediments by vertical motion of the grounding line during tidal cycles, and 2) by the tidally driven motion of grounded or near-grounded icebergs. These data also enable the mapping of small GZWs that show the location of short-term still-stands or re-advances of the ice-sheet grounding zone. No meltwater channels are identified from our data, suggesting that free-flowing meltwater may not be essential for the formation of GZWs or MSGLs. The examples presented here show how high-resolution AUV-derived geophysical data provide a step-change in our ability to image seafloor glacial landforms, enabling new interpretations about past ice dynamics and glacial sedimentation at fine temporal and spatial scales.

中文翻译：

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从高分辨率自主水下航行器数据对海底冰川地貌形成的新见解

摘要 靠近海底部署的自主水下航行器（AUV）可以获取有关海底地形和浅层地层的高分辨率地球物理数据，但在冰川地貌和冰盖重建领域的应用有限。在这里，我们展示了在南极半岛东北部大陆架的三次 AUV 潜水中获得的多波束回波探测、侧扫声纳、海底剖面仪和高分辨率合成孔径声纳 (HISAS) 数据。这些数据使冰川地貌，包括巨型冰川线 (MSGL)、接地带楔形 (GZW) 和冰山犁痕，能够以几十厘米的水平分辨率成像，从而可以识别细微的形态特征。我们绘制了潮汐脊的地图，这些潮脊被解释为 1) 沿着冰盖接地线，通过在潮汐周期期间接地线的垂直运动挤压软海底沉积物，以及 2) 通过接地或近地冰山。这些数据还能够绘制小型 GZW 的地图，以显示冰盖接地区的短期静止或重新前进的位置。从我们的数据中没有发现融水通道，这表明自由流动的融水可能不是 GZW 或 MSGL 的形成所必需的。此处提供的示例展示了高分辨率 AUV 衍生的地球物理数据如何为我们对海底冰川地貌成像的能力提供了一个阶段性的变化，从而能够在精细的时间和空间尺度上对过去的冰动态和冰川沉积进行新的解释。