Northeast Greenland - Digital Bathymetric Compilation, with links to DBM in ArcGIS format

A new digital bathymetric model (DBM) for the Northeast Greenland (NEG) continental shelf (74°N - 81°N) is presented. The DBM has a grid cell size of 250 m × 250 m and incorporates bathymetric data from 30 multibeam cruises, more than 20 single-beam cruises and first reflector depths from industrial seismic lines. The new DBM substantially improves the bathymetry compared to older models. The DBM not only allows a better delineation of previously known seafloor morphology but, in addition, reveals the presence of previously unmapped morphological features including glacially derived troughs, fjords, grounding-zone wedges, and lateral moraines. These submarine landforms are used to infer the past extent and ice-flow dynamics of the Greenland Ice Sheet during the last full-glacial period of the Quaternary and subsequent ice retreat across the continental shelf. The DBM reveals cross-shelf bathymetric troughs that may enable the inflow of warm Atlantic water masses across the shelf, driving enhanced basal melting of the marine-terminating outlet glaciers draining the ice sheet to the coast in Northeast Greenland. Knolls, sinks, and hummocky seafloor on the middle shelf are also suggested to be related to salt diapirism. North-south-orientated elongate depressions are identified that probably relate to ice-marginal processes in combination with erosion caused by the East Greenland Current. A single guyot-like peak has been discovered and is interpreted to have been produced during a volcanic event approximately 55 Ma ago.

本研究构建了一款适用于东北格陵兰（Northeast Greenland，简称NEG）大陆架（北纬74°~81°）的新型数字水深模型（Digital Bathymetric Model，简称DBM）。该模型的网格单元尺寸为250 m × 250 m，整合了30次多波束测深航次、20余次单波束测深航次的水深数据，以及工业地震测线获取的第一反射界面深度数据。相较于早期模型，这款新型DBM显著优化了水深数据的精度与完整性。该模型不仅能够更精准地刻画已认知的海底地貌形态，还揭示了此前未被测绘的多种地貌特征，包括冰川成因槽谷、峡湾、冰盖接地带楔体与侧碛堤。上述海底地貌可用于反演第四纪末次冰盛期及后续冰盖跨大陆架冰退过程中，格陵兰冰盖的古分布范围与冰流动力学特征。该DBM还识别出跨陆架槽谷，这类槽谷可能为暖大西洋水团跨陆架输入提供了通道，进而加剧了东北格陵兰沿岸入海终端出口冰川的冰床底部消融速率。陆架中部的海丘、沉陷洼地与起伏不平的海底，也被认为与盐底辟作用相关。研究同时识别出南北向延伸的狭长洼地，其成因可能与东格陵兰洋流侵蚀叠加冰缘过程有关。此外，本次研究发现了一座桌状海山状海峰，经解释其形成于约55 Ma前的一次火山活动事件。