Sediments covering Arctic continental shelves are uniquely impacted by ice processes. Delivery of sediments is generally limited to the summer, when rivers are ice free, permafrost bluffs are thawing, and sea ice is undergoing its seasonal retreat. Once delivered to the coastal zone, sediments follow complex pathways to their final depocenters—for example, fluvial sediments may experience enhanced seaward advection in the spring due to routing under nearshore sea ice; during the open-water season, boundary-layer transport may be altered by strong stratification in the ocean due to ice melt; during the fall storm season, sediments may be entrained into sea ice through the production of anchor ice and frazil; and in the winter, large ice keels more than 20 m tall plow the seafloor (sometimes to seabed depths of 1–2 m), creating a type of physical mixing that dwarfs the decimeter-scale mixing from bioturbation observed in lower-latitude shelf systems. This review summarizes the work done on subtidal sediment dynamics over the last 50 years in Arctic shelf systems backed by soft-sediment coastlines and suggests directions for future sediment studies in a changing Arctic. Reduced sea ice, increased wave energy, and increased sediment supply from bluffs (and possibly rivers) will likely alter marine sediment dynamics in the Arctic now and into the future.

中文翻译：

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北极大陆架沉积物动力学


覆盖北极大陆架的沉积物受到冰过程的独特影响。沉积物的输送通常仅限于夏季，此时河流无冰，永久冻土悬崖正在融化，海冰正在季节性消退。一旦输送到沿海地区，沉积物就会沿着复杂的路径到达其最终的沉积中心——例如，由于在近岸海冰下布线，河流沉积物可能会在春季经历增强的向海平流;在开阔水域季节，由于冰融化，海洋中的强烈分层可能会改变边界层运输;在秋季风暴季节，沉积物可能会通过锚冰和 FRAZIL 的产生被夹带到海冰中;在冬季，超过 20 m 高的大型冰龙骨犁地犁地在海底（有时达到 1-2 m 的海底深度），形成一种物理混合，使在低纬度大陆架系统中观察到的生物扰动产生的分米级混合相形见绌。本文总结了过去 50 年在以软沉积物海岸线为支撑的北极大陆架系统中对潮下带沉积物动力学所做的工作，并为不断变化的北极未来沉积物研究提出了方向。海冰减少、波浪能增加以及悬崖（可能还有河流）的沉积物供应增加，可能会改变北极现在和未来的海洋沉积物动态。