The Scoresby Sund piedmont glacier

The LGM maximum (Flakkerhuk) stage is shown by the location of the Kap Brewster moraine complex.  When the ice front was at that position Scoresby Sund and Jameson Land must have been covered by a very large piedmont lobe.  Evidence suggests that the ice was grounded all the way out to the Kap Brewster moraine. The Milne Land stage, around 10,000 years ago, represents a readvance which did not progress much beyond the trough exits.  Note from the text below that some researchers believe that Jameson Land was covered at the time of the LGM and others think it was ice-free!

On pondering about the nature of the Celtic Sea piedmont glacier, I am focussing more and more on Nordvestfjord, Scoresbysund and Jameson Land.  The parallels are striking.  In Nordvestfjord, a very large outlet glacier / ice stream like the Irish Sea Glacier, inputs from the flanks like those that came in from the Welsh ice cap and the Irish ice cap, a sudden deceleration / decanting of ice (Hall Bredning and St George's Channel), further inputs from the west (glacier ice from the Renland and Milne Land glaciers and in the case of the Celtic Sea piedmont, from southern Ireland) and finally a spreading of the ice southwards and eastwards over gentler terrain (Scoresbysund and Jameson Land in the case of Greenland and the Celtic Sea floor and the Bristol Channel floor -in the British case -- both probably above relative sea-level at the time -- so there would have been no ice shelves) -- except maybe off the set coast.

The Scoresby Sound piedmont was apparently grounded -- the water depth in the sound today is between 400m and 600m (much shallower water than in the feeder fjords).  Global sea level at the time was probably more than 100m lower than today.  But there were much greater isostatic depressions and rebounds here than in the Celtic Sea -- the implications need careful thought......

Running diagonally across this satellite image -- Nordvestfjord. the biggest of the outlet glacier routes.  Hall Breeding is speckled with icebergs.

Nordvestfjord landscape -- near the entrance of Gurreholmsdal. The trough walls are in places almost 2,000 m high -- and the fjord water is in places more than 1,500 m deep.  So the trough depth is c 3,500m or about 11,000 feet.

Fjord walls typical of the fjord system, near the Bear Islands.  Renland in the background  -- a "vertical landscape".....

Jameson Land -- a rolling lowland with ancient valleys and low hill masses.  For many years it was thought that the landscape bore no traces of glaciation.....  

Two images of the Jameson Land tundra landscape -- by contrast with the fjord landscape, this is dominated by wide horizons and "horizontal" features.

=================

https://core.ac.uk/download/pdf/11771291.pdf

Gabriele Uenzelmann-Neben (1992) Scoresby Sund, East Greenland: Structure and Distribution of Sedimentary Rocks.
Polarforschung 62 (1): 1-9, 1992 (erschienen 1993)

In Scoresby Sund, the Pleistocene was a time characterized by erosion. Thicker deposits can be found only at the valley mouths, high mountain plateaus and the coast of Jameson Land (FUNDER 1990). The occurrence pattern of Quaternary sediments documents a number of glacial-interglacial cycles. The oldest sediments (Lodin Elv formation) found on land are of Pliocene/Pleistocene age. The most expanded glaciation, the Scoresby Sund Glacial, occurred around 200 ka (FUNDER 1972, 1984, 1989) and represents an important stratigraphic marker (HJORT & MÖLLER 1991; HJORT & SALVIGSEN 1991). Sediments deposited during the Langelandselv Interglacial (Eemian 120 ka, FUNDER 1990) can be found only along the southwestern coast of Jameson Land. This interglacial showed higher temperatures than the present and can be correlated with isotopic stage Se (BÖCHER & BENNICKE 1991). The first two Early Weichselian glacials (Glaciation 1 and 2 during the Jameson Land Marine Episode) showed neither an ice cover of the outer fjord areas (FUNDER 1989) nor of Jameson Land (FUNDER et al. 1991). During the Flakkerhuk Glacial (late Early Weichselian, FUNDER et al. 1991) a thick floating glacier extended out onto the shelf while Jameson Land stayed uncovered (FUNDER 1989, 1990). Glaciation 4 (Late Weichselian, FUND ER et al. 1991) commenced about 20 to 13 ka. Until present, it has been considered to be a minor glacial stage. Thick glaciers terminated at the mouths of the western fjords into Hall Bredning and Scoresby Sund during the Milne Land Stage (11 - 9.5 ka, HJORT 1979). After a continuous retreat of the glaciers astandstill followed during the Rodefjord Stage (FUNDER 1971). The end of that phase resembles the present ice extent.

Some refs

Dowdeswell, JA, Villinger, H., Whittington, R.J. & Marienfeld, P. (1991): The Quaternary marine record in the Scoresby Sund fjord system, East Greenland: preliminary results and interpretation. In: P. Möller.; Ch. Hjort & O. Ingolfsson, eds., The last interglacial-glacial cycle: preliminary report on the PONAM fieldwork in Jameson Land and Scoresby Sund, East Greenland. Lundqua Reports 33: 149-156, Lund.

Dowdeswell, JA, Uenzelmann-Neben, G. & Whittington, R.J. (submitted): The Late Quaternary sedimentary record in Scoresby Sund, East Greenland. - Boreas.

Funder. S. (1971): Observations on the Quaternary Geology of the Rodefjord Region, Scoresby Sund. - Rapport Grenlands Geologiske Undersogelse 37, Copenhagen.

Funder. S. (1972): Remarks on the Quaternary geology of Jameson Land and adjacent areas, Scoresby Sund, East Greenland. - Rapports Gronlands Geologiske Undersogelse 48: 93-98, Copenhagen.

Funder. S. (1984): Chronology of the last interglacial/glacial cycle in Greenland: First approximation. - In: W.c. Mahaney (ed.), Correlation of Quaternary chronologies, 261-279, GeoBooks, Norwich,

Funder. S. (1989): Quaternary Geology of the ice-free areas and adjacent shelves of Greenland. - In: J.R. Fulton (ed.), Quaternary Geology of Canada and Greenland. Geological Survey of Canada, Geology of Canada No I.

Funder. S. (1990): Quaternary Map of Greenland, 1:500000, Sheet 12, Descriptive Text. - Geological Survey of Greenland, Copenhagen.

Funder. S.; Hjort, CH & Landvik, IY. (1991): Quaternary stratigraphy of Jameson Land - a first approximation. - In: P. Möller; Ch. Hjort & O. Ingolfsson eds., The last interglacial-glacial cycle: preliminary report on the PONAM fieldwork in Jameson Land and Scoresby Sund, East Greenland. Lundqua Reports 33: 171-176, Lund.

GEBCO (1980): General bathymetric chart of the oceans. - Chart No. 5.04, Canadian Hydrographie Service, Ottawa.

Hinz, K., Mutter, J.C., Zehnder, C.M. & NGT Study Group (1987): Symmetrie conjugation of continent-ocean boundary structures along the Norwegian and East Greenland Margins. Mar. Petr. Geology 4: 166-187.

Hjort, Ch. (1979): Glaciation in northern East Greenland during Late Weichselian and Early Flandrian. - Boreas 3: 281-296.

Hjort, Ch. & Möller P. (1991): Glacial deposits on the interior plateaux of Jameson Land, East Greenland. - In: P. Möller; Ch. Hjort & O. Ingolfsson (eds.), The last interglacial-glacial cycle: preliminary report on the PONAM fieldwork in Jameson Land and Scoresby Sund, East Greenland. Lundqua Reports 33: 7-22, Lund.

Hjort, Ch. & Salvigsen, O. (1991): The channel & tor-landscape in southeastern Jameson Land, East Greenland. - In: P. Möller; Ch.

Hjort & O. Ingolfsson (eds.), The last interglacial-glacial cycle: preliminary report on the PONAM fieldwork in Jameson Land and Scoresby Sund, East Greenland. Lundqua Reports 33: 23-26, Lund.

==========================

Another interesting paper:

Funder, S. & Hansen, L. (1996): The Greenland ice sheet - a model for its culmination and decay during and after the last glacial maximum. Bulletin of the Geological Society of Denmark, Vol. 42, pp. 137-152. Copenhagen, 1996-02-01.

https://2dgf.dk/xpdf/bull42-02-137-152.pdf

Extracts

Onshore studies at the mouth of Scoresby Sund have shown that the large grounded outlet glacier which filled the fjord basin during LGM, the Flakkerhuk stade, was thin and less than 400 m thick at the fjord mouth (Mangerud & Funder 1994; Tveranger, HoumarkNielsen, Løvberg & Mangerud 1994). It probably had its front on the "Kap Brewster sedimentary ridge", a 20 km wide, 175 m high, and more than 30 km long ridge of Quaternary sediments which has been located from air gun and bathymétrie data at the fjormouth (Fig. 4 and Dowdeswell, Uenzelmann-Neben, Whittington & Marienfeld 1994). This is in agreement with ice core studies on a local ice cap which showed that the Inland Ice during LGM was drained through the deep fjord troughs and never invaded the adjacent mountain plateaus at c. 2000 m a.s.l. (Johnsen, Clausen, Dansgaard, Gundestrup, Hansson, Jonsson, Steffensen & Sveinbjømsdottir 1992). Recent seismic studies have indicated that a similar but smaller moraine-like ridge occurs at the mouth of Kong Oscar Fjord to the north of Scoresby Sund, but is lacking from other fjords (Hubberten, Grobe, Jokat, Melles, Niessen & Stein 1995). Coring on the shelf and its edge at the mouth of Scoresby Sund and at Hochstetter Forland show maximum fluxes of terrigenous material and pulses of IRD indicating the presence of ice bergs and melt water from glacier fronts on the shelf between 16 and 21 ka. This was correlated with LGM in Scoresby Sund, the Flakkerhuk stade (Nam, Stein, Grobe & Hubberten 1995; Stein, Nam, Grobe & Hubberten in press). The history of the glacier in Scoresby Sund is discussed further below.

Scoresby Sund between 16 and 10 ka

The Scoresby Sund drainage system is the largest single outlet from the eastern margin of the Inland Ice. Owing to work during the PONAM Project this area has the most detailed record of events during and after LGM (Funder, Hjort & Landvik 1994), and current field work has added to this. The position of ice margins and key-14C dates are shown on Fig. 4, and details of the 14C-dates are given in Table 1. As noted above, a large outlet glacier filled the fjord system during LGM probably with its front on the Kap Brewster sedimentary ridge, between 16 and 21 ka (Fig.4). Six thousand years later, during the Milne Land stade, the glacier fronts had receded c. 150 km and uncovered the outer fjord basin. Current studies on western Jameson Land show that the glacial history during and after LGM began when the glacier in Scoresby Sund ran along the present coastline and deposited proglacial sediments along the margin and in blocked river valley basins. Next, during the peak of glaciation, the glacier expanded inland over the ice dammed lake basins, up to 15 kilometres from the coast and deposited thin and discontinuous till over the area. After this, the ice melted, maybe with lakes dammed against its margin. In the final collapse much of the land based ice was transformed to dead-ice as seen from the numerous kames. The retreating ice front was followed by marine water, and the present pattern of fluvial drainage was established with marine limit at c. 70 m above sea level in western Jameson Land. During the Milne Land stade the fjord glaciers advanced to positions on the western margin of the Scoresby Sund basin, but did not reinvade western Jameson Land (Fig. 4).