Retreat patterns and dynamics of the former Norske Trough ice stream (NE Greenland): An integrated geomorphological and sedimentological approach
Metadatos
Mostrar el registro completo del ítemAutor
López Quirós, Adrián; Junna, Tuomas; Davies, Joanna; Andresen, Katrine J.; Nielsen, Tove; Haghipour, Negar; Wacker, Lukas; Alstrup, Aage Kristian Olsen; Munk, Ole Lajord; Rasmussen, Tine L.; Pearce, Christof; Seidenkrantz, Marit-SolveigEditorial
Elsevier
Materia
Submarine landforms Sediment cores Paleoceanography LGM ice extent Ice retreat Holocene Northeast Greenland
Fecha
2024-02-01Referencia bibliográfica
López Quirós, A. et al. Retreat patterns and dynamics of the former Norske Trough ice stream (NE Greenland): An integrated geomorphological and sedimentological approach. Quaternary Science Reviews 325 (2024) 108477. [https://doi.org/10.1016/j.quascirev.2023.108477]
Patrocinador
Independent Research Fund Denmark 0135–00165 B; Danish Centre for Marine Research, the Engineering Research Council of Canada; Independent Research Fund Denmark 7014-00113 B/FNU; Spanish Ministry of Science and Innovation FJC 2021-047046-I; NextGenerationEU/PRTRResumen
A better understanding of past extent and dynamics of the Greenland Ice Sheet (GrIS) is required to provide context for present-day observations, to constrain numerical climate models and to predict future scenarios of ice-sheet response to recent climatic change. The presence of a grounded GrIS on the NE Greenland shelf during the Last Glacial Maximum (LGM) is supported by high-resolution seismic data combined with multi-proxy analyses of sediment gravity cores from Norske Trough. Our results indicate that an ice stream advanced to the outer shelf during the LGM. Recessional moraines and grounding zone wedges on the seafloor of the outer to middle shelf show that initial retreat was episodic, punctuated by two major stillstands. Pinning points for grounding-zone stabilization were controlled by pre-LGM trough topography. In contrast, preserved large-scale glacial lineations on the seafloor of the inner shelf, formed during the advance, indicate that ice retreat from the inner trough to the coast-proximal position was rapid in order to maintain the former carved morphology. Initial ice retreat was underway before 16.6 cal Kyr BP, earlier than previously known for this sector of the NE Greenland shelf. The inner shelf was free from grounded ice at least by 12.5 cal Kyr BP, and likely before. Retreat occurred in a glaciomarine setting and the ice sheet was fringed by a floating ice shelf. There is no evidence of grounded-ice readvances during the Younger Dryas, although a floating ice shelf with vigorous sea-ice and iceberg rafting production occupied the inner shelf at 11.3 cal Kyr BP. 14C dates reveal initial stepwise ice retreat followed by a fast retreat that coincides with Heinrich Stadial 1 and the Bølling-Allerød interstadial, respectively. During both periods there was increased inflow of warm Atlantic Water, indicating a strong ocean/climate control on the late deglaciation of Norske Trough. Following the late deglaciation, postglacial (Holocene) sedimentation records a change from an ice-distal glaciomarine environment, to an open marine environment and complete ice shelf disintegration. On the innermost shelf of the Norske Trough, the ice shelf disintegrated and reformed once before the final break-up occurred at 9.6 cal Kyr BP.