Southern outlet of the Northeast Greenland Ice Stream, NE Greenland: post-Last Glacial Maximum response to climate warming

• Main Authors: Zoller, Kevin, Laberg, Jan Sverre, Rydningen, Tom Arne, Husum, Katrine, Forwick, Matthias
• Format: Text
• Language: English
• Published: 2023
• Subjects: Greenland; Dove Bugt; Bessel fjord; Dove bugt; Ice Sheet
• Online Access: https://doi.org/10.5194/egusphere-2022-970; https://egusphere.copernicus.org/preprints/2022/egusphere-2022-970/

The Greenland Ice Sheet (GrIS) responds rapidly to the present climate; therefore, its response to the predicted future warming is of concern. To learn more about the impact of future climatic warming on the ice sheet, decoding its behavior during past periods of warmer than present climate is important. However, due to the scarcity of marine studies reconstructing ice sheet conditions on the Northeast Greenland shelf and adjacent fjords, the timing of the deglaciation over marine regions and its connection to forcing factors remain poorly constrained. This includes data collected in fjords that encompass the Holocene thermal maximum (HTM), a period in which the climate was warmer than it is at present. This paper aims to use new bathymetric data and the analysis of sediment gravity cores to enhance our understanding of ice dynamics of the GrIS in a fjord and inner shelf environment as well as give insight into the timing of deglaciation and provide a palaeoenvironmental reconstruction of southwestern Dove Bugt and Bessel Fjord since the Last Glacial Maximum (LGM). North–south-oriented glacial lineations and the absence of pronounced moraines in southwest Dove Bugt, an inner continental shelf embayment (trough), suggest the southwards and offshore flow of Storstrømmen, the southern branch of the Northeast Greenland Ice Stream (NEGIS). Sedimentological data suggest that an ice body, theorized to be the NEGIS, may have retreated from the region slightly before ∼ 11.4 cal ka BP. The seabed morphology of Bessel Fjord, a fjord terminating in southern Dove Bugt, includes numerous basins separated by thresholds. The position of basin thresholds, which include some recessional moraines, suggest that the GrIS had undergone multiple halts or readvances during deglaciation, likely during one of the cold events identified in the Greenland Summit temperature records. A minimum age of 7.1 cal ka BP is proposed for the retreat of ice through the fjord to or west of its present-day position in the Bessel Fjord catchment area. ...