Supplementary Data for: Glacial erosion and Quaternary landscape development of the Eurasian Arctic

This dataset contains a high-resolution palaeo-topography reconstruction of the Eurasian Arctic through the Quaternary (<2.74 Ma). NetCDF files of palaeo-topographies on 20 km grids are provided for each of the 47 major interglacials before the present day.
Article abstract: Multiple ice age cycles spanning the last three million years have fundamentally transformed the Arctic landscape. The cadence, intensity and pattern of this glacial modification underpin the stability of Arctic geosystems over geologic time scales, including its hydrology, circulation patterns, slope stability, hydrocarbon fluid flow, geochemical/sediment cycling and nutrient supply. The Barents Shelf provides a unique arena to investigate long-term landscape evolution as it has undergone significant glacial modification during the Quaternary and has an extensive stratigraphic data repository motivated by decades of hydrocarbon seismic and well exploration. Here, we assimilate new geological datasets with ice sheet erosion modelling to incrementally reconstruct the geomorphic evolution of the Eurasian Arctic domain over each of the 47 glaciations since the intensification of Northern Hemisphere glaciation ~2.74 Ma. We utilise this time-transgressive framework to review hypotheses regarding the heterogenous development of the Barents Shelf and the timing of key topographic reconfiguration episodes. Our results demonstrate that up to 2.6 km of bedrock was glacially removed to the shelf margins, and though the mean rate of erosion declines over the Quaternary, the efficacy of glacial erosion has a more complex timeline. Initially, erosion was highly effective as large expanses of the Eurasian Arctic switched from subaerial exposure to marine conditions around 2 Ma ago. Thereafter, erosional efficacy decreased as the landscape desensitized to successive glaciations but, after 1 Ma, it increased as a dynamic, marine-based ice sheet drained by ice streams expanded, selectively eroding large outlet troughs to the shelf edge. Critically for Arctic climate, at ~0.69 Ma this episode of enhanced preferential erosion opened up the Barents Seaway establishing a new circulation pathway between the Atlantic and Arctic Oceans. Our 4D landscape reconstruction provides key boundary conditions for paleoclimate models and establishes a new framework for assessing the profound impact of late-Cenozoic glaciation on the Eurasian Arctic landscape.

本数据集包含第四纪（Quaternary，<2.74 Ma，即274万年前至今）欧亚北极区域的高分辨率古地形（palaeo-topography）重建成果。针对现今之前的47个主要间冰期，均提供了20千米网格下的古地形NetCDF文件。论文摘要：过去三百万年间的多轮冰期循环从根本上重塑了北极地貌。此类冰川改造的节律、强度与模式，是地质时间尺度下北极地质系统稳定性的核心支撑，涵盖北极水文、环流格局、斜坡稳定性、油气流体运移、地球化学/沉积物循环以及养分供给等多个方面。巴伦支海陆架（Barents Shelf）是研究长期地貌演化的独特平台：该区在第四纪期间经历了显著的冰川改造，且凭借数十年油气地震与钻井勘探积累了海量地层数据资源。本研究整合全新地质数据集与冰盖侵蚀模拟模型，逐步重建了自约274万年前北半球冰期强化以来，47次冰期事件中欧亚北极区域的地貌演化历程。本研究依托该穿时演化框架，针对巴伦支海陆架的非均质性演化以及关键地形重构事件的发生时序，对相关假说进行了系统梳理与评述。研究结果显示，总计可达2.6千米的基岩被冰川剥蚀并搬运至陆架边缘；尽管第四纪期间平均侵蚀速率呈下降趋势，但冰川侵蚀效能的时间演化过程更为复杂。约200万年前，随着欧亚北极大片区域从陆上暴露转为海洋环境，冰川侵蚀效能极高。此后，随着地貌对后续冰期的响应逐渐钝化，侵蚀效能有所下降；但在100万年后，随着由冰流（ice streams）引流的动态海洋基型冰盖扩张，冰川侵蚀效能再度提升，该冰盖选择性地在陆架边缘侵蚀出大型出口槽谷。对北极气候而言尤为关键的是，约69万年前，此次增强的选择性侵蚀作用打通了巴伦支海道（Barents Seaway），构建起大西洋与北冰洋之间全新的环流通道。本研究的四维（4D）地貌重建成果为古气候模型（paleoclimate models）提供了关键边界条件，同时为评估晚新生代（late-Cenozoic）冰川作用对欧亚北极地貌的深远影响搭建了全新研究框架。