Observations on the Quaternary geology around Nioghalvfjerdsfjorden, eastern North Greenland

1999 ◽  
pp. 56-60
Author(s):  
Ole Bennike ◽  
Anker Weidick
Keyword(s):  
Late Summer ◽  
Open Water ◽  
Quaternary Geology ◽  
Mean Annual Precipitation ◽  
Outlet Glacier ◽  
Ice Caps ◽  
North East ◽  
Pack Ice ◽  
Lake Deposits ◽  
North Greenland

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Bennike, O., & Weidick, A. (1999). Observations on the Quaternary geology around Nioghalvfjerdsfjorden, eastern North Greenland. Geology of Greenland Survey Bulletin, 183, 56-60. https://doi.org/10.34194/ggub.v183.5205 _______________ In North and North-East Greenland, several of the outlet glaciers from the Inland Ice have long, floating tongues (Higgins 1991). Nioghalvfjerdsfjorden (Fig. 1) is today occupied by a floating outlet glacier that is about 60 km long, and the fjord is surrounded by dissected plateaux with broad valleys (Thomsen et al. 1997). The offshore shelf to the east of Nioghalvfjerdsfjorden is unusually broad, up to 300 km wide (Cherkis & Vogt 1994), and recently small low islands were discovered on the western part of this shelf (G. Budeus and T.I.H. Andersson, personal communications 1998). Quaternary deposits are widespread around Nioghalvfjerdsfjorden and include glacial, glaciofluvial, marine, deltaic and ice lake deposits. Ice margin features such as kame deposits and moraines are also common (Davies 1972). The glaciation limit increases from 200 m a.s.l. over the eastern coastal islands to 1000 m in the inland areas; local ice caps and valley glaciers are common in the region, although the mean annual precipitation is only about 200 mm per year. Most of the sea in the area is covered by permanent sea ice, with pack ice further east, but open water is present in late summer in some fjords north of Nioghalvfjerdsfjorden, and in the Nordøstvandet polynia.

scholarly journals Glaciological Studies in Iceland with Erts-I Imagery

1975 ◽  
Vol 15 (73) ◽  
pp. 465-466 ◽  
Author(s):  
Richard S. Williams ◽  
ÁgÚst Bödvarsson ◽  
SigurjÓn Rist ◽  
KristjÁn SÆmundsson ◽  
Sigurdur Thorarinsson
Keyword(s):  
Late Summer ◽  
Time Lapse ◽  
Structural Features ◽  
List Type ◽  
Outlet Glacier ◽  
Glacial Ice ◽  
Ice Caps ◽  
North East ◽  
The North ◽  
Geothermal Activity

Under a long-term, bi-national, multi-disciplinary research project between the U.S. Geological Survey and various Icelandic scientific organizations, MSS imagery from the ERTS-I satellite is being used to study the varied dynamic environmental phenomena of Iceland, including its glaciers and ice caps. Initial analysis of the ERTS-I imagery has shown the importance of the repetitive imagery to: Record relatively short-term glaciological changes. According to measurements made on two ERTS-I images, taken 11 months apart, an outlet glacier in the north-east part of Vatnajökull, had surged 1.8 km. A combination of field observations and analysis of ERTS imagery shows a total surge in excess of 3 km which probably took place in a few months, perhaps in as little as a few weeks. Contorted moraines on another of Vatnajökull’s outlet glaciers, Skeiðararjökull, on the south-east coast, show a movement of 600 m in an 11 month period even though the snout of the glacier remained in essentially the same position. Several glacier-margin lakes have been observed to change in size during the year (1972-73), particularly Grjœnalón, which continued to enlarge in area each time it was imaged until its size diminished markedly after a jökulhlaup partially emptied the lake in August 1973. Seasonal changes in the size of sediment plumes along the coast, where glacial rivers debouch their sediment-laden water into the ocean, can also be observed in a time-lapse manner. Furnish the data necessary to revise certain glaciological features on maps, and to produce ortho-image maps of ice caps directly from ERTS imagery, at least to map scales of 1: 250 000. Sufficient ERTS-I imagery of Iceland from the late summer and early fall of 1973 now exists to map accurately, from a planimetric standpoint, 90% of that area of Iceland covered by glacial ice (previously estimated to be 11.5% of total area of Iceland). Optimum imagery (minimum snow cover, maximum exposure of glacial ice) has been obtained of Vatnajökull, Langjrikull, Hofsjökull, Myrdalsjökull, and Eyjafjallajökull or five (including the four biggest) of the seven largest ice caps in Iceland and five of the smaller (less than 50 km2) ice caps as well. On 19 August 1973 Hofsjökull had an area of 915 km- on ERTS imagery. Its area has usually been cited as 996 km2. On a 1945 Danish Geodetic Institute map (1: 500 000) the area is 981 km2; U.S. Army maps (1 : 250 000, 1969) show an area of 943 km2. Map subglacial volcanic and structural features. Within or at the margins of the ice caps and outlet glaciers, a number of new glaciological, structural, and volcanic features can be mapped from ERTS-I imagery, particularly at low solar illumination angles (<10°) including several probable subglacial central volcanoes, calderas, and tectonic lineaments. Some of the effects of jökulhlaups can be mapped, including subsidence cauldrons resulting from subglacial volcanic or intense geothermal activity.

scholarly journals Glaciological Studies in Iceland with Erts-I Imagery

1975 ◽  
Vol 15 (73) ◽  
pp. 465-466
Author(s):  
Richard S. Williams ◽  
Ágúst Bödvarsson ◽  
Sigurjón Rist ◽  
Kristján Sæmundsson ◽  
Sigurdur Thorarinsson
Keyword(s):  
Late Summer ◽  
Time Lapse ◽  
Structural Features ◽  
List Type ◽  
Outlet Glacier ◽  
Glacial Ice ◽  
Ice Caps ◽  
North East ◽  
The North ◽  
Geothermal Activity

Under a long-term, bi-national, multi-disciplinary research project between the U.S. Geological Survey and various Icelandic scientific organizations, MSS imagery from the ERTS-I satellite is being used to study the varied dynamic environmental phenomena of Iceland, including its glaciers and ice caps. Initial analysis of the ERTS-I imagery has shown the importance of the repetitive imagery to: Record relatively short-term glaciological changes. According to measurements made on two ERTS-I images, taken 11 months apart, an outlet glacier in the north-east part of Vatnajökull, had surged 1.8 km. A combination of field observations and analysis of ERTS imagery shows a total surge in excess of 3 km which probably took place in a few months, perhaps in as little as a few weeks. Contorted moraines on another of Vatnajökull’s outlet glaciers, Skeiðararjökull, on the south-east coast, show a movement of 600 m in an 11 month period even though the snout of the glacier remained in essentially the same position.Several glacier-margin lakes have been observed to change in size during the year (1972-73), particularly Grjœnalón, which continued to enlarge in area each time it was imaged until its size diminished markedly after a jökulhlaup partially emptied the lake in August 1973. Seasonal changes in the size of sediment plumes along the coast, where glacial rivers debouch their sediment-laden water into the ocean, can also be observed in a time-lapse manner.Furnish the data necessary to revise certain glaciological features on maps, and to produce ortho-image maps of ice caps directly from ERTS imagery, at least to map scales of 1: 250 000. Sufficient ERTS-I imagery of Iceland from the late summer and early fall of 1973 now exists to map accurately, from a planimetric standpoint, 90% of that area of Iceland covered by glacial ice (previously estimated to be 11.5% of total area of Iceland). Optimum imagery (minimum snow cover, maximum exposure of glacial ice) has been obtained of Vatnajökull, Langjrikull, Hofsjökull, Myrdalsjökull, and Eyjafjallajökull or five (including the four biggest) of the seven largest ice caps in Iceland and five of the smaller (less than 50 km2) ice caps as well. On 19 August 1973 Hofsjökull had an area of 915 km- on ERTS imagery. Its area has usually been cited as 996 km2. On a 1945 Danish Geodetic Institute map (1: 500 000) the area is 981 km2; U.S. Army maps (1 : 250 000, 1969) show an area of 943 km2.Map subglacial volcanic and structural features. Within or at the margins of the ice caps and outlet glaciers, a number of new glaciological, structural, and volcanic features can be mapped from ERTS-I imagery, particularly at low solar illumination angles (<10°) including several probable subglacial central volcanoes, calderas, and tectonic lineaments. Some of the effects of jökulhlaups can be mapped, including subsidence cauldrons resulting from subglacial volcanic or intense geothermal activity.

scholarly journals Time budget patterns and complementary use of a Mediterranean wetland (Tonga, North-east Algeria) by migrant and resident waterbirds

2016 ◽  
Vol 86 (1) ◽  
pp. 55 ◽  
Author(s):  
Elafri Ali ◽  
Halassi Ismahan ◽  
Houhamdi Moussa
Keyword(s):  
Coastal Wetlands ◽  
Time Budget ◽  
Quantitative Description ◽  
Late Summer ◽  
Open Water ◽  
Feeding Time ◽  
Time Budgets ◽  
North East ◽  
Species Specific ◽  
Open Water Body

We carried out a quantitative description of the use of a Mediterranean wetland (Tonga, North-east Algeria) by 22 waterbirds species (11 residents and 11 Palaearctic migrants) during late summer-wintering period, also analyzing their species-specific diurnal time budgets and the main related features of the landscape. The analyses of similarity in time budgets across birds (Hierarchal Cluster Analysis) showed four clusters of species associated with four major activities: day time mostly feeding (11 species), sleeping (6), swimming (3) and resting (2). Residents (Herons and Rails) showed a higher feeding time when compared to migrants (diving ducks, Gulls and Cormorants). From late summer to winter the time budget activity change in migrants; in contrast residents behave uniformly among daytime and at the course of the season. The use of this natural wetland in a complementary way by a high number of waterbirds (residents and migrants), is principally promoted by the existing of numerous habitat types. We found that 3 main ecological units, open water body, mudflats, and flooded meadows were the most utilized as foraging habitats among grebes, rails, ducks, gulls, and herons. In contrast, floating-leafed vegetation, and tall emergent vegetation were the commonest habitat categories used in resting activities especially by cormorants and herons. Data on behaviour requirements of these waterbirds can be used for conservation and correct management of this and other Mediterranean coastal wetlands.

scholarly journals Organic matter pathways to zooplankton and benthos under pack ice in late winter and open water in late summer in the north-central Bering Sea

2005 ◽  
Vol 291 ◽  
pp. 135-150 ◽  
Author(s):  
JR Lovvorn ◽  
LW Cooper ◽  
ML Brooks ◽  
CC De Ruyck ◽  
JK Bump ◽  
...  
Keyword(s):  
Organic Matter ◽  
Bering Sea ◽  
Late Summer ◽  
Open Water ◽  
Late Winter ◽  
North Central ◽  
The North ◽  
Pack Ice

Occurrence and effects of open water in McMurdo Sound, Antarctica, during winter and early spring

Polar Record ◽  
1967 ◽  
Vol 13 (87) ◽  
pp. 775-778 ◽  
Author(s):  
B. Stonehouse
Keyword(s):  
Late Summer ◽  
Open Water ◽  
Early Spring ◽  
Easy Access ◽  
High Latitudes ◽  
Mcmurdo Sound ◽  
Pack Ice ◽  
Fast Ice

McMurdo Sound is well known as an area comparatively free from fast ice during the middle and late summer. Although closed to its discoverer in February 1841 by contrary winds, pack ice and new ice (Ross, 1847), the sound provided easy access to high latitudes in January and February on at least ten occasions between 1902 and 1916. Since 1955, icebreakers have assisted shipping movements in November and December, and possibly helped in dispersing the winter fast ice by cutting wide channels from Cape Bird southward. However, northerly swells and south-easterly gales are sufficient in most years to disperse fast ice from the southern end of the sound by mid or late February (Heine, 1963).

British Universities East Greenland Expedition, 1974

Polar Record ◽  
1976 ◽  
Vol 18 (112) ◽  
pp. 76-77
Author(s):  
D. W. Matthews
Keyword(s):  
North Atlantic Ocean ◽  
Volcanic Rocks ◽  
Open Water ◽  
East Greenland ◽  
North East ◽  
The North ◽  
Pack Ice ◽  
The North Sea ◽  
Made In

This expedition to the Blosseville Kyst area of east Greenland was wholly geological, comprising several groups brought together under the leadership of Professor P. E. Brown of Aberdeen University. It aimed to follow up geological discoveries which had been made in 1971 by expeditions from Cambridge and Sheffield, and also to pursue several new lines of research directed primarily at relating the sediments and volcanic rocks in east Greenland to the birth of the North Atlantic Ocean. The expedition chartered mv Signalhorn from Martin Karlsen AS of Brandal, Norway, for a period of 52 days; after some delay, due to a mechanical emergency in the North Sea, she sailed from Aberdeen on 20 July. The journey was slow and rough and featured an abortive attempt to take the shorter route round north-east Iceland. On 26 July the east Greenland coast was sighted at lat 68 N in fine weather. Aputitq and the Kangerdlugssuaq area were beset by heavy pack ice, but good progress was made northwards along Blosseville Kyst through moderately open water about five miles offshore.

scholarly journals Glacier velocities from aerial photographs in North and North-East Greenland

1988 ◽  
Vol 140 ◽  
pp. 102-105
Author(s):  
A.K Higgins
Keyword(s):  
Sea Ice ◽  
Aerial Photographs ◽  
Surface Pattern ◽  
East Greenland ◽  
Ice Caps ◽  
North East ◽  
Glacier Terminus ◽  
Stable Conditions ◽  
Glacier Velocity ◽  
North Greenland

General descriptions of the glaciers of North and North-East Greenland have been given by Koch (1928), Davies & Krinsley (1962) and Weidick (1975). These descriptions, however, provide little in the way of quimtitative data on glacier velocities, although Davies & Krinsley cancluded that a large number af glaciers and small ice caps in North Greenland exhibited stable conditions, with a significant number showing evidence of recent retreat. Comparisons of vertical aerial photographs taken in 1959-63, 1971 and 1978 permit measurements ef glacier velocity to be made on floating ice tongues which have preserved a distinctive surface pattern of meandering streams and crevasses. These show the largest glaciers draining the Inland Ice in North and North-East Greenland to have average velocities ranging from 300 to 900 m/year. This study of vertical aerial photographs has also demonstrated that for floating glacier tongues the position of the glacier terminus is not areliable indicator of advance or retreat. In the fjords of North Greenland semi-permanent sea ice often maintains the integrity of advancing floating glacier fronts for periods of ten to twenty years (Koch, 1928; Weidick, 1975); the break-up of the floating tongue in rare summers when the sea ice melts completely may give the impression of a sudden retreat, but this 'retreat' is unrelated to changes in the mass balance.

scholarly journals Quaternary geology of western and central North Greenland

1992 ◽  
Vol 153 ◽  
pp. 1-34
Author(s):  
M Kelly ◽  
O Bennike
Keyword(s):  
Sea Level ◽  
Slow Rate ◽  
Late Holocene ◽  
Ice Sheet ◽  
Quaternary Geology ◽  
Glacial Sediments ◽  
Ice Caps ◽  
Marine Fossils ◽  
Late Weichselian ◽  
North Greenland

The earliest Quaternary event represented is the Kap Bryant glacial stade of probable Saalian age, in which an ice sheet covered the area out to the shelf. In contrast, in the Late Weichselian Kap Fulford stade, the area was only partly glaciated, with outlet lobes from an ice sheet occupying the outer fjords. There is some evidence of an earlier (Early Weichselian?) slightly more extensive glaciation (Kap Sumner stade). In the early Holocene, the ice margin had retreated to the middle regions of the fjords and extensive glacial lakes were formed in intervening areas. The Late Holocene Steensby stade produced a readvanee of the ice sheet at the head of the fjords and the growth of local ice caps. Reworked marine fossils in glacial sediments define the Hall Land marine event of Eemian and/or Early Weichselian age. The Late Weichselian/Holocene marine event (Nyeboe Land event) is abundantly represented by deposits whose distribution shows that the limit of transgression varied over the area, with a maximum at about 125 m above sea level. Regression from this limit occurred during the Holocene, initially at a slow rate. The fossil biota are described from the marine sediments and from a small number of terrestrial occurrences.

A new volcanic province: evidence from glacial erratics in western North Greenland

2000 ◽  
pp. 35-41 ◽  
Author(s):  
Peter R. Dawes ◽  
Bjørn Thomassen ◽  
T.I. Hauge Andersson
Keyword(s):  
Volcanic Rocks ◽  
Iron Formation ◽  
Banded Iron Formation ◽  
Common Component ◽  
Volcanic Province ◽  
North West ◽  
North East ◽  
The North ◽  
Surficial Deposits ◽  
North Greenland

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Dawes, P. R., Thomassen, B., & Andersson, T. H. (2000). A new volcanic province: evidence from glacial erratics in western North Greenland. Geology of Greenland Survey Bulletin, 186, 35-41. https://doi.org/10.34194/ggub.v186.5213 _______________ Mapping and regional geological studies in northern Greenland were carried out during the project Kane Basin 1999 (see Dawes et al. 2000, this volume). During ore geological studies in Washington Land by one of us (B.T.), finds of erratics of banded iron formation (BIF) directed special attention to the till, glaciofluvial and fluvial sediments. This led to the discovery that in certain parts of Daugaard-Jensen Land and Washington Land volcanic rocks form a common component of the surficial deposits, with particularly colourful, red porphyries catching the eye. The presence of BIF is interesting but not altogether unexpected since BIF erratics have been reported from southern Hall Land just to the north-east (Kelly & Bennike 1992) and such rocks crop out in the Precambrian shield of North-West Greenland to the south (Fig. 1; Dawes 1991). On the other hand, the presence of volcanic erratics was unexpected and stimulated the work reported on here.

Investigations of past climate and sea-ice variability in the fjord area by Station Nord, eastern North Greenland

1969 ◽  
Vol 35 ◽  
pp. 67-70 ◽  
Author(s):  
Niels Nørgaard-Pedersen ◽  
Sofia Ribeiro ◽  
Naja Mikkelsen ◽  
Audrey Limoges ◽  
Marit-Solveig Seidenkrantz
Keyword(s):  
Sea Ice ◽  
Outer Part ◽  
Late Summer ◽  
Field Work ◽  
The Arctic ◽  
Research Station ◽  
Fjord System ◽  
Sea Bottom ◽  
Satellite Radar ◽  
North Greenland

The marine record of the Independence–Danmark fjord system extending out to the Wandel Hav in eastern North Greenland (Fig. 1A) is little known due to the almost perennial sea-ice cover, which makes the region inaccessible for research vessels (Nørgaard-Pedersen et al. 2008), and only a few depth measurements have been conducted in the area. In 2015, the Villum Research Station, a new logistic base for scientific investigations, was opened at Station Nord. In contrast to the early exploration of the region, it is now possible to observe and track the seasonal character and changes of ice in the fjord system and the Arctic Ocean through remote sensing by satellite radar systems. Satellite data going back to the early 1980s show that the outer part of the Independence–Danmark fjord system is characterised by perennial sea ice whereas both the southern part of the fjord system and an area 20–30 km west of Station Nord are partly ice free during late summer (Fig. 1B). Hence, marine-orientated field work can be conducted from the sea ice using snow mobiles, and by drilling through the ice to reach the underlying water and sea bottom.

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