Repeated ice streaming on the northwest Greenland continental shelf since the onset of the Middle Pleistocene Transition

Abstract

Abstract. Ice streams provide a fundamental control on ice sheet discharge and depositional patterns along glaciated margins. This paper investigates ancient ice streams by presenting the first 3D seismic geomorphological analysis of a major glacigenic succession offshore Greenland. In Melville Bugt, northwest Greenland, six sets of landforms (five buried and one on the seafloor) have been interpreted as mega-scale glacial lineations (MSGLs) that provide evidence for extensive ice streams on outer palaeo-shelves. A gradual change in mean MSGL orientation and associated depocentres through time suggests that the palaeo-ice flow and sediment transport pathways migrated in response to the evolving submarine topography through each glacial–interglacial cycle. The stratigraphy and available chronology show that the MSGLs are confined to separate stratigraphic units and were most likely formed after the onset of the Middle Pleistocene Transition at ∼1.3 Ma. The MSGL record in Melville Bugt suggests that since ∼1.3 Ma, ice streams have regularly advanced across the continental shelf during glacial stages. High-resolution buried 3D landform records such as these have not been previously observed anywhere on the Greenland continental shelf margin and provide a crucial benchmark for testing how accurately numerical models are able to recreate past configurations of the Greenland Ice Sheet.

A Continuous Seismostratigraphic Framework for the Western Svalbard-Barents Sea Margin Over the Last 2.7 Ma: Implications for the Late Cenozoic Glacial History of the Svalbard-Barents Sea Ice Sheet

“…This is supported by the first signs of extensive glacial erosion on the Yermak Plateau (Mattingsdal et al, 2014) and observations of streamlined subglacial landforms and extensive glaciotectonism (deformation of rocks or sediment due to the overriding or pushing of ice) formed by ice streams reaching the shelf-edge in the southwestern Barents Sea at this time (e.g., Andreassen et al, 2004Andreassen et al, , 2007Laberg et al, 2010). During the Middle Pleistocene Transition (MPT ∼1.3-0.7 Ma) ice sheet expansions have also been documented, both from seismic and sedimentological data, on the east Greenland margin (Laberg et al, 2018;Pérez et al, 2018), the northwestern Greenland margin (Newton et al, 2020), the mid-Norwegian margin (Montelli et al, 2017;Newton and Huuse, 2017), the North Sea (Rea et al, 2018), and North America (Balco and Rovey, 2010), implying a regional expansion of all major Northern Hemisphere ice sheets (Newton et al, 2020).…”

Expedition 400 Preliminary Report: NW Greenland Glaciated Margin

“…The site was aimed at retrieving a continuous highresolution record of ice-ocean processes spanning the early late Pleistocene. The depth target was the base of an expanded drift-channel succession situated on the lower slope between the Melville Bugt and Upernavik TMFs that are the modern expression of major paleoice streams draining the NGrIS (Knutz et al, 2019;Newton et al, 2017Newton et al, , 2020Newton et al, , 2021. The sedimentary succession is covered https://doi.org/10.14379/iodp.pr.400.2024 publications.iodp.org • 18…”

Geohazard detection using 3D seismic data to enhance offshore scientific drilling site selection

“…IODP Proposal 909 site locations are shown as well as the associated stratigraphic targets of each site (I-VII). Shallow cores that were drilled by a consortium led by Shell that provide stratigraphic information used within the proposal are also shown (Acton, 2012;Nøhr-Hansen et al, 2018). The location of the key regional 2D seismic transect used for original site selection is also shown and represents the location of Fig.…”

“…The north-western Greenland margin is a frontier petroleum province, with potential Cretaceous source rocks identified across the region in shallow cores and outcrop ( Fig. 1) (Acton, 2012;Bojesen-Koefoed et al, 2004;Nøhr-Hansen et al, 2018;Núñez-Betelu, 1993) as well as deep unexplored sedimentary rift basins (Henriksen et al, 2009). The area experienced a surge in oil and gas exploration activity between 2007 and 2014, resulting in five exploration licenses being awarded within Melville Bay and the acquisition of extensive 2D and 3D seismic datasets.…”