Circulation over the South‐East Greenland Shelf and Potential for Liquid Freshwater Export: a Drifter Study

2021 ◽  
Author(s):  
E. Duyck ◽  
M.F. De Jong
Keyword(s):  
The South ◽  
East Greenland ◽  
Freshwater Export

Freshwater export from the south-east Greenland shelf into the Irminger Sea and relation to wind events

2021 ◽  
Author(s):  
Elodie Duyck ◽  
Femke De Jong
Keyword(s):  
Surface Water ◽  
Ekman Transport ◽  
The Arctic ◽  
The South ◽  
Overturning Circulation ◽  
East Greenland ◽  
East Greenland Current ◽  
Irminger Sea ◽  
Freshwater Export ◽  
Wind Events

<p>Greenland Ice Sheet melt and freshening of the Arctic Ocean lead to increased discharge of freshwater into the East Greenland Current. If this additional freshwater reaches the convective regions of the Subpolar North Atlantic it could weaken deep mixing and affect the strength of the Atlantic Meridional Overturning Circulation. In particular, freshwater exported away from the South-East Greenland shelf could affect deep convection in the Irminger Sea, which has recently been shown to have a key role in the Atlantic overturning circulation. Though export of fresh shelf surface water is well observed west of Greenland, there is still little insight into surface water export from the East Greenland shelf to the Irminger Sea.</p><p>The East Greenland Current Drifter Investigation of Freshwater Transport drifter deployment conducted in August 2019 at 65°N on the eastern side of Greenland, resulted in five out of 30 drifters being exported away from the east Greenland shelf, four of which were exported at Cape Farewell. The specific wind regime at Cape Farewell is a potential driving factor for enhanced freshwater export in the area. While persistent south-eastward barrier winds push surface waters to the coast over most of the eastern shelf, Cape Farewell experiences strong eastward wind events such as tip-jets that could cause off-shelf export. Using wind data from the ERA-5 atmospheric reanalysis, we compute Ekman transport along the east Greenland shelf. We find greater probability for off-shelf Ekman transport at Cape Farewell than along the rest of the shelf, confirming that the area is the most likely to contribute to wind-driven freshwater export to the Irminger Sea. Wind and surface velocity data from a high-resolution model (2 km) are used to further investigate and quantify freshwater export at Cape Farewell and how it relates to local wind events.</p>

Mafic igneous rocks and mineralisation in the Palaeoproterozoic Ketilidian orogen, South-East Greenland: project SUPRASYD 1996

1997 ◽  
pp. 66-74
Author(s):  
Henrik Stendal ◽  
Wulf Mueller ◽  
Nicolai Birkedal ◽  
Esben I. Hansen ◽  
Claus Østergaard
Keyword(s):  
Mineral Exploration ◽  
Volcanic Rocks ◽  
Shear Zones ◽  
Field Work ◽  
Igneous Rocks ◽  
Border Zone ◽  
The South ◽  
East Greenland ◽  
North West ◽  
Arc Setting

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Stendal, H., Mueller, W., Birkedal, N., Hansen, E. I., & Østergaard, C. (1997). Mafic igneous rocks and mineralisation in the Palaeoproterozoic Ketilidian orogen, South-East Greenland: project SUPRASYD 1996. Geology of Greenland Survey Bulletin, 176, 66-74. https://doi.org/10.34194/ggub.v176.5064 _______________ The multidisciplinary SUPRASYD project (1992–96) focused on a regional investigation of the Palaeoproterozoic Ketilidian orogenic belt which crosses the southern tip of Greenland. Apart from a broad range of geological and structural studies (Nielsen et al., 1993; Garde & Schønwandt, 1994, 1995; Garde et al., 1997), the project included a mineral resource evaluation of the supracrustal sequences associated with the Ketilidian orogen (e.g. Mosher, 1995). The Ketilidian orogen of southern Greenland can be divided from north-west to south-east into: (1) a border zone in which the crystalline rocks of the Archaean craton are unconformably overlain by Ketilidian supracrustal rocks; (2) a major polyphase pluton, referred to as the Julianehåb batholith; and (3) extensive areas of Ketilidian supracrustal rocks, divided into psammitic and pelitic rocks with subordinate interstratified mafic volcanic rocks (Fig. 1). The Julianehåb batholith is viewed as emplaced in a magmatic arc setting; the supracrustal sequences south of the batholith have been interpreted as either (1) deposited in an intra-arc and fore-arc basin (Chadwick & Garde, 1996), or (2) deposited in a back-arc or intra-arc setting (Stendal & Swager, 1995; Swager, 1995). Both possibilities are plausible and infer subduction-related processes. Regional compilations of geological, geochemical and geophysical data for southern Greenland have been presented by Thorning et al. (1994). Mosher (1995) has recently reviewed the mineral exploration potential of the region. The commercial company Nunaoil A/S has been engaged in gold prospecting in South Greenland since 1990 (e.g. Gowen et al., 1993). A principal goal of the SUPRASYD project was to test the mineral potential of the Ketilidian supracrustal sequences and define the gold potential in the shear zones in the Julianehåb batholith. Previous work has substantiated a gold potential in amphibolitic rocks in the south-west coastal areas (Gowen et al., 1993.), and in the amphibolitic rocks of the Kutseq area (Swager et al., 1995). Field work in 1996 was focused on prospective gold-bearing sites in mafic rocks in South-East Greenland. Three M.Sc. students mapped showings under the supervision of the H. S., while an area on the south side of Kangerluluk fjord was mapped by H. S. and W. M. (Fig. 4).

scholarly journals Oceanic heat delivery via Kangerdlugssuaq Fjord to the south-east Greenland ice sheet

2014 ◽  
Vol 119 (2) ◽  
pp. 631-645 ◽  
Author(s):  
Mark E. Inall ◽  
Tavi Murray ◽  
Finlo R. Cottier ◽  
Kilian Scharrer ◽  
Timothy J. Boyd ◽  
...  
Keyword(s):  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
The South ◽  
East Greenland

scholarly journals Glaciological observations in the south-western Scoresby Sund region. A preliminary report

1973 ◽  
Vol 58 ◽  
pp. 49-54
Author(s):  
O.B Olesen ◽  
N Reeh
Keyword(s):  
Preliminary Report ◽  
The South ◽  
East Greenland ◽  
Fjord System ◽  
Ice Production ◽  
Rate Of Movement

The glaciological work on the 1972 geological expedition to Scoresby Sund, East Greenland, was an expansion of the observations made on the expedition in 1968 (see Olesen & Reeh, 1969). In 1968 observations on rate of movement and estimations of the calve-ice production in the northern parts of the Seoresby Sund fjord complex were carried out. A natural continuation of this study was to observe the remainder of the major glaciers, draining the lnland lce into the southern parts of the same fjord system.

scholarly journals Jurassic dinoflagellate cyst stratigraphy of Store Koldewey, North-East Greenland

2004 ◽  
Vol 5 ◽  
pp. 99-112 ◽  
Author(s):  
Stefan Piasecki ◽  
John H. Callomon ◽  
Lars Stemmerik
Keyword(s):  
Middle Jurassic ◽  
Upper Jurassic ◽  
Dinoflagellate Cysts ◽  
The South ◽  
Important Species ◽  
East Greenland ◽  
Sequence Stratigraphic ◽  
Fine Grained ◽  
North East ◽  
The North

The Jurassic of Store Koldewey comprises a Middle Jurassic succession towards the south and an Upper Jurassic succession towards the north. Both successions onlap crystalline basement and coarse sediments dominate. Three main lithostratigraphical units are recognised: the Pelion Formation, including the Spath Plateau Member, the Payer Dal Formation and the Bernbjerg Formation. Rich marine macrofaunas include Boreal ammonites and the successions are dated as Late Bathonian – Early Callovian and Late Oxfordian – Early Kimmeridgian on the basis of new collections combined with material in earlier collections. Fine-grained horizons and units have been analysed for dinoflagellate cysts and the stratigraphy of the diverse and well-preserved flora has been integrated with the Boreal ammonite stratigraphy. The dinoflagellate floras correlate with contemporaneous floras from Milne Land, Jameson Land and Hold with Hope farther to the south in East Greenland, and with Peary Land in North Greenland and Svalbard towards the north. The Middle Jurassic flora shows local variations in East Greenland whereas the Upper Jurassic flora gradually changes northwards in East Greenland. A Boreal flora occurs in Peary Land and Svalbard. The characteristic and stratigraphically important species Perisseiasphaeridium pannosum and Oligosphaeridium patulum have their northernmost occurrence on Store Koldewey, whereas Taeniophora iunctispina and Adnatosphaeridium sp. extend as far north as Peary Land. Assemblages of dinoflagellate cysts are used to characterise significant regional flooding events and extensive sequence stratigraphic units.

scholarly journals Remarks on the Quaternary geology of Jameson Land and adjacent areas, Scoresby Sund, East Greenland

1972 ◽  
Vol 48 ◽  
pp. 93-98
Author(s):  
S Funder
Keyword(s):  
Quaternary Geology ◽  
Field Observations ◽  
East Side ◽  
The South ◽  
East Greenland ◽  
The North ◽  
South West

During the summer of 1971 mapping of Quatemary geology was carried out in the eastem part of the Scoresby Sund region: along the coasts of Jameson Land, at the head of Carlsberg Fjord, around Scoresbysund settlement and at the mouth of Schuchert Dal to the north of Hall Bredning. Observations made by K. Birkenmajer and M. Aellen on the distribution of erratic boulders and extent of glaciation in areas to the south and south-west of Carlsberg Fjord and along the east side of Schuchert Dal were kindly made available to me. The work this summer marked the completion of a 'three summer project' of Quatemary mapping in the region. Some results from the first two summers have been published previously (Funder, 1970, 1971). In the map (map 4) some significant field observations have been presented. The distribution of 'Jameson Land plateau drift deposits' on the map is mainly based on observations by F. Surlyk and T. Birkelund which kindly have been put at my disposal. Sample localities of C14 dates are plotted on the map; a list of these dates with short abstracts is found at the end of this report.

scholarly journals The high-grade gneisses in the south-west of Dove Bugt: an old gneiss complex in a deep part of the Caledonides of North-East Greenland

1991 ◽  
Vol 152 ◽  
pp. 103-111
Author(s):  
B Chadwick ◽  
C.R.L Friend
Keyword(s):  
Granitic Rocks ◽  
Small Scale ◽  
High Grade ◽  
Deep Part ◽  
The South ◽  
East Greenland ◽  
North East ◽  
Gneiss Complex ◽  
South West

The complex range of orthogneisses has been subdivided on the basis of field characteristics into an old polyphase group, grey phlebitic gneisses, younger varieties of pink granitic gneisses that occur principally as extensive sheets, mixed orthogneisses with schlieric facies and undifferentiated gneisses with dioritic facies. Mafic sheets, now amphibolites, were emplaced at various stages in the evolution of the gneisses. Enclaves and sheets of supracrustal rocks include paragneisses, graphitic schists, marble, amphibolite and stratiform gabbroic complexes with anorthosite. Nappes with curvilinear hinge lines and belts of mylonite developed in high amphibolite conditions after emplacement of the sheets of pink granitic rocks (now variably deformed gneisses) into the old orthogneisses and supracrustal rocks. Principal displacements in the mylonites were shallow and N-directed. The nappes and mylonites were deformed by upright-inclined folds with north-westerly vergence. The nappes, mylonites and north-westerly verging folds are presumed to be Caledonian. N- and S-directed extensions indicated by small-scale ductile structures younger than the regional folding suggest that longitudinal collapse predominated in this part of the Caledonian belt in the south-west of Dove Bugt.

Seismic investigation of the East Greenland volcanic rifted margin

1997 ◽  
pp. 50-54
Author(s):  
Trine Dahl-Jensen ◽  
W. Steven Holbrook ◽  
John R. Hopper ◽  
Peter B. Kelemen ◽  
Hans Christian Larsen ◽  
...  
Keyword(s):  
Oceanic Crust ◽  
Upper Mantle ◽  
High Velocity ◽  
Lower Crust ◽  
The South ◽  
East Greenland ◽  
Seismic Investigation ◽  
Iceland Plume ◽  
Greenland Margin ◽  
Rifted Margin

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Dahl-Jensen, T., Holbrook, W. S., Hopper, J. R., Kelemen, P. B., Larsen, H. C., Detrick, R., Bernstein, S., & Kent, G. (1997). Seismic investigation of the East Greenland volcanic rifted margin. Geology of Greenland Survey Bulletin, 176, 50-54. https://doi.org/10.34194/ggub.v176.5061 _______________ The SIGMA project (Seismic Investigation of the Greenland MArgin) was designed to make accurate measurements of crustal thickness, velocity structure and seismic reflectivity along the hotspot-influenced volcanic rifted margin (VRM) off South-East Greenland (Fig. 1). SIGMA is a joint project between researchers at Woods Hole Oceanographic Institution (Woods Hole, Mass., USA) and the Danish Lithosphere Centre (DLC), and data was acquired on a cruise with R/V Maurice Ewing in August–October 1996. VRMs are characterised by a prism of igneous rocks that occupies the continent–ocean transition zone in an 80 to 150 km wide belt, several times thicker than normal oceanic crust, and which extends in some regions for more than 1500 km along strike. This thick igneous crust has two characteristics on seismic data: a seawarddipping reflector sequence (SDRS) interpreted as subaerially erupted basalt flows and intercalated volcanoclastics, and a high-velocity lower crust with P-wave velocities (7.2–7.6 km/s) suggestive of mafic to ultramafic intrusive rocks (Hinz, 1981; Mutter et al., 1982, 1984, 1988; Larsen & Jakobsdóttir, 1988; White & McKenzie, 1989; Holbrook & Kelemen, 1993). Several models for the thermal and mechanical processes involved in the formation of VRMs have been proposed, including: decompression melting during passive upwelling near a mantle plume (White & McKenzie, 1989); actively upwelling plume heads impinging on the base of the lithosphere (Richards et al., 1989; Duncan & Richards, 1991; Griffiths & Campbell, 1991); enhanced upper mantle convection driven by steep, cold lithospheric edges adjacent to the rift (Mutter et al., 1988) and hot upper mantle due to non-plume ‘hot cells’ or insulation by supercontinents (Gurnis, 1988). SIGMA consists of four transects systematically sampling the structure of the South-East Greenland margin and the continent–ocean transition at increasing distance from the Iceland hotspot track, in order to investigate the South-East Greenland VRM with respect to the following questions:1) What is the structure of the transition from continental to thick igneous crust, and thence to normal oceanic crust? Is the transition abrupt or gradual? To what extent does faulting play a role? Does the abruptness of the continent–ocean boundary change with distance from the Iceland plume? 2) What was the total volume of magmatism during continental breakup on the South-East Greenland margin and its conjugates, and how does it vary in space and time? How does this magmatism relate to distance from the Iceland plume and to its temporal magmatic budget? What is the proportion of plutonic to volcanic rocks, and how does this vary with distance from the hotspot track and with total crustal thickness? 3) Does high velocity lower crust exist beneath the margin, and if so, is there any evidence that its composition, thickness, and distribution change along strike? How might such changes relate to variations in melting conditions (temperature and degree of melting) with distance from the plume? 4) Is the structure of the South-East Greenland margin symmetrical with its conjugate margins on the Hatton–Rockall Bank and Iceland–Faeroes Ridge? What combinations of pure shear and simple shear processes might explain the conjugate structures?

scholarly journals ODP Leg 163, South-East Greenland volcanic rifted margin

1996 ◽  
Vol 172 ◽  
pp. 103-112
Author(s):  
H.C Larsen ◽  
R.S Duncan ◽  
J.F Allan ◽  
ODP Leg 163 shipboard party
Keyword(s):  
Oceanic Crust ◽  
The South ◽  
The West ◽  
East Greenland ◽  
Early Tertiary ◽  
Greenland Margin ◽  
Rifted Margin

The South-East Greenland margin is a type example of a volcanic rifted margin. The margin is characterised by a broad seaward-dipping reflector sequence (SDRS) composed of basalt that onlaps continental (mainly Precambrian) crust to the west and terminates eastward in oceanic crust of early Tertiary age (Figs 1, 2).

scholarly journals New zircon U-Pb and Hf isotopic constraints on the crustal evolution of the Skjoldungen region, South-East Greenland

1969 ◽  
Vol 35 ◽  
pp. 55-58
Author(s):  
Thomas F. Kokfelt ◽  
Tomas Næraa ◽  
Kristine Thrane ◽  
Leon Bagas
Keyword(s):  
Mineral Resources ◽  
Geological Survey ◽  
Crustal Evolution ◽  
Crustal Growth ◽  
Isotopic Data ◽  
The South ◽  
Joint Project ◽  
East Greenland ◽  
History Of ◽  
Isotopic Constraints

We report new zircon U-Pb and Hf isotopic data from the Skjoldungen region between c. 62°30´ and 63°40´N in South- East Greenland. The work was carried out under the South- East Greenland Mineral Endowment Task (SEGMENT); a joint project between the Geological Survey of Denmark and Greenland (GEUS) and the Ministry of Mineral Resources (MMR) in Greenland to assess the mineral endowment and update the geological knowledge of the region using modern petrological, geochemical and geochronological tools. This paper presents new zircon U-Pb and Hf isotopic data from a range of different Archaean rocks in the Skjoldungen region, which greatly improve the understanding of the history of crustal growth.

Sign in / Sign up

Export Citation Format

Share Document