Fluctuations in lemming populations in north Yukon, Canada, 2007–2010

2011 ◽  
Vol 89 (4) ◽  
pp. 297-306 ◽  
Author(s):  
Charles J. Krebs ◽  
Donald Reid ◽  
Alice J. Kenney ◽  
Scott Gilbert
Keyword(s):  
Coastal Plain ◽  
The Arctic ◽  
North Coast ◽  
Male Body ◽  
Peak Density ◽  
The North ◽  
Live Trapping ◽  
Winter Snow ◽  
Dicrostonyx Groenlandicus ◽  
Snow Conditions

We estimated population density of brown lemmings ( Lemmus sibiricus (Kerr, 1792)), Greenland collared lemmings ( Dicrostonyx groenlandicus (Traill, 1823)), and tundra voles ( Microtus oeconomus (Pallas, 1776)) on Herschel Island from 2007 to 2010 by mark–recapture on three live-trapping areas. Limited data were also available from Komakuk Beach on the north Yukon coast. In contrast to most previous studies, brown and collared lemmings were partly out of phase. Brown lemmings on Herschel reached peak density in 2007–2008 and were low in 2009–2010, while collared lemmings were at peak density in 2007–2008 and again in 2010. Large adult male body size was characteristic of peak populations. Brown lemmings increased dramatically in the peak summer of 2008 and collared lemmings increased rapidly when winter breeding under the snow was successful in 2009–2010. By contrast, at Komakuk Beach, we could see no clear signs of fluctuations in these three species. Winter snow conditions may be too severe for population persistence on the coastal plain along the north coast of the Yukon. Further work is needed to unravel why peak lemming densities are so variable among sites and why lemming fluctuations are so pronounced on the arctic coastal plain of Alaska and virtually absent on the coastal plain of the north Yukon.

scholarly journals Snowfall and Oxygen-Isotope Variations off the North Coast of Ellesmere Island, N.W.T., Canada

1987 ◽  
Vol 33 (114) ◽  
pp. 195-199 ◽  
Author(s):  
Martin O. Jeffries ◽  
H. Roy Krouse
Keyword(s):  
Arctic Ocean ◽  
High Arctic ◽  
Geographic Region ◽  
Ellesmere Island ◽  
The Arctic ◽  
North Coast ◽  
Snow Pack ◽  
The North ◽  
Winter Snow ◽  
The Mean

AbstractSnow-pack along the land-fast ice fringe off the north coast of Ellesmere Island was generally characterized by depth-hoar overlain by dense snow and wind slab. Mean snow depth in the study area was 0.54 m (1982-85) and the mean δ18O value of the snow-pack was -31.3˚/00. Isotope data were not obtained previously for this geographic region and, therefore, complement a previous study of δ18O variations in High Arctic snow (Koerner, 1979). The data are consistent with an Arctic Ocean moisture source. The δ18O profiles show seasonal variations, with winter snow being more depleted in 18O than fall and spring snow. However, the δ18O profiles are dominated by a trend to higher δ18O values with increasing depth. This is attributed to a decrease in δ18O values as condensation temperatures fall during the autumn-winter accumulation period. During this time, there is also a change from relatively open to almost complete ice cover in the Arctic Ocean. The change in evaporation conditions and consequent effect on δ values gives rise to a sharp discontinuity in the δ18O profiles and a bi-modal δ18O frequency distribution. The bi-modal distribution is reinforced by a secondary isotope fractionation that occurs during depth-hoar formation. This isotope effect leads to a wider δ18O range but does not significantly alter the mean δ18O value.

scholarly journals Snowfall and Oxygen-Isotope Variations off the North Coast of Ellesmere Island, N.W.T., Canada

1987 ◽  
Vol 33 (114) ◽  
pp. 195-199 ◽  
Author(s):  
Martin O. Jeffries ◽  
H. Roy Krouse
Keyword(s):  
Arctic Ocean ◽  
High Arctic ◽  
Geographic Region ◽  
Ellesmere Island ◽  
The Arctic ◽  
North Coast ◽  
Snow Pack ◽  
The North ◽  
Winter Snow ◽  
The Mean

AbstractSnow-pack along the land-fast ice fringe off the north coast of Ellesmere Island was generally characterized by depth-hoar overlain by dense snow and wind slab. Mean snow depth in the study area was 0.54 m (1982-85) and the mean δ18O value of the snow-pack was -31.3˚/00. Isotope data were not obtained previously for this geographic region and, therefore, complement a previous study of δ18O variations in High Arctic snow (Koerner, 1979). The data are consistent with an Arctic Ocean moisture source. The δ18O profiles show seasonal variations, with winter snow being more depleted in18O than fall and spring snow. However, the δ18O profiles are dominated by a trend to higher δ18O values with increasing depth. This is attributed to a decrease in δ18O values as condensation temperatures fall during the autumn-winter accumulation period. During this time, there is also a change from relatively open to almost complete ice cover in the Arctic Ocean. The change in evaporation conditions and consequent effect on δ values gives rise to a sharp discontinuity in the δ18O profiles and a bi-modal δ18O frequency distribution. The bi-modal distribution is reinforced by a secondary isotope fractionation that occurs during depth-hoar formation. This isotope effect leads to a wider δ18O range but does not significantly alter the mean δ18O value.

Chapter 20 Paleogene history

1997 ◽  
Vol 17 (1) ◽  
pp. 388-417
Keyword(s):  
Early Cretaceous ◽  
The Arctic ◽  
North Coast ◽  
Western Coast ◽  
Central Basin ◽  
Oblique Collision ◽  
The North ◽  
Western Border ◽  
Paleozoic Rocks ◽  
West Spitsbergen

The Paleogene chapter of Svalbard history is a quite distinct one. It begins with an unconformity, albeit a sub-parallel one representing a late Cretaceous hiatus. Resting on Albian and older strata, the Van Mijenfjorden Group of six formations totals a thickness of about 2500 m in the Central Basin of Spitsbergen. The outcrop is ringed by Early Cretaceous strata in a broad syncline (Fig. 20.1). The strata are largely non-marine, coal-bearing sandstones, with interbedded marine shales and they range in age through Paleocene and Eocene.From latest Paleocene through Eocene time the West Spitsbergen Orogeny caused (Spitsbergian) deformation along the western border of the Central Basin, but it is most conspicuous in the folding and thrusting of Carboniferous through Early Cretaceous rocks. The orogen extended westwards to and beyond the western coast of central and southern Spitsbergen including Precambrian and Early Paleozoic rocks, which had already been involved in earlier tectogenesis. The eastward-verging thrusting extended beneath the Tertiary basin and reactivated older faults to the east.In the wider context Svalbard, adjacent to the north coast of Greenland, had been an integral part of Pangea from Carboniferous through Cretaceous time. The northward extension of the Atlantic opening reached and initiated the spreading of the Arctic Eurasia Basin at the beginning of the Paleogene Period. This led to the separation of Svalbard together with the Barents Shelf and northern Europe from Greenland by dextral strike-slip transform faulting. In the course of this progression, oblique collision between northeast Greenland and Svalbard caused

scholarly journals Aspects of the Glaciology of Meighen Island, Northwest Territories, Canada

1965 ◽  
Vol 5 (40) ◽  
pp. 399-410 ◽  
Author(s):  
K. C. Arnold
Keyword(s):  
Snow Accumulation ◽  
The Arctic ◽  
North Coast ◽  
Ice Cap ◽  
The North ◽  
Four Seasons ◽  
Northern Half ◽  
Northern Edge ◽  
Summer Temperatures ◽  
Made In

Abstract Meighen Island lies in the centre of the north coast of the Queen Elizabeth Islands and fronts on the Arctic Ocean. An ice cap of about 76 km.2 covers about one-tenth of the island. Its greatest thickness of 150 m. occurs under the summit, near the south end, which was 268 m. above sea-level in 1960. The northern half of the ice cap is less than 30 m. thick; and the total volume is of the order of 2,000 × 106 m.3. Precipitation is low in the northern Queen Elizabeth Islands, and Meighen Island lies in an area where summer temperatures are lowest. In the winters of 1959–60, 1960–61 and 1961–62, the snow accumulation was 12.6, 18.2 and 14.1 cm. of water equivalent. Some snowfall remained on the higher part of the ice cap in the cold summer of 1961; but the ice cap diminished in volume in each year; by 36 × 106, 72 × 106, 22 × 106 and 91 × 106 m.3 in the 1959, 1960, 1961 and 1962 ablation seasons. If the conditions of these four seasons were maintained the ice cap would disappear in about 100 yr. However, a radio-carbon dating of a saxifrage exposed by the retreat of the ice from a small nunatak near the northern edge gave a date of less than 100 yr., and it appears that the existence of the ice cap might be sensitively related to recent climatic change. Careful surveys were made in 1959, 1960 and 1961 in an attempt to detect movement in the ice cap. Unequivocal evidence is not available from these surveys; but the stake network has been maintained and another survey has recently been completed.

scholarly journals The Walrus

Oryx ◽  
1950 ◽  
Vol 1 (1) ◽  
pp. 10-14
Author(s):  
Colin Matheson
Keyword(s):  
Distinct Species ◽  
The Arctic ◽  
North Coast ◽  
Hudson Bay ◽  
Pacific Walrus ◽  
The North ◽  
The Pacific ◽  
Western Shore ◽  
Far Eastern ◽  
Siberian Coast

The Walrus is confined to the northern circumpolar regions, its range northward apparently extending to the limit of perpetual ice. Now rare in Iceland, Odobenus rosmarus is stated to be still not unfamiliar in Hudson Bay, Davis Strait, and Baffin Bay north to Ellesmere Land, the coasts of Greenland, Spitsbergen, Novaia Zemlia, and the western part of the north coast of Siberia; in all of which regions, however, persecution has greatly diminished its numbers. The species does not extend along the far eastern part of the north Siberian coast, and Walrus are not met with again until the north-eastern extremity of Siberia is reached. Here the Pacific Walrus, which differs somewhat from that of the Atlantic side and is regarded as a distinct species, Odobenus obesus, is reported from Cape Chelagskai, in longitude 170° E., along the Siberian coast as far as northern Kamschatka south to latitude 60°, also on some of the islands in the Bering Sea, and on the opposite coast of Alaska south to about latitude 55° and eastward to Point Barrow. Here again a long gap along the Arctic coast of North America, from Point Barrow in longitude 158° W. to the western shore of Hudson Bay in longitude 97° W., separates the Pacific from the Atlantic Walrus.

Sea Ice in the Greenland Polynya in 2018 - A Study with CryoSat-2 and SMOS

2020 ◽  
Author(s):  
Weixin Zhu ◽  
Lu Zhou ◽  
Shiming Xu
Keyword(s):  
Sea Ice ◽  
Global Climate ◽  
Arctic Sea Ice ◽  
Climate System ◽  
The Arctic ◽  
Ice Thickness ◽  
Sea Ice Thickness ◽  
The North ◽  
Ice Surface ◽  
Snow Conditions

<p><strong>Abstract</strong></p><p>Arctic sea ice is a critical component in the global climate system. It affects the climate system by radiating incident heat back into space and regulating ocean-atmosphere heat and momentum. Satellite altimetry such as CryoSat-2 serves as the primary approach for observing sea ice thickness. Nevertheless, the thickness retrieval with CryoSat-2 mainly depends on the height of the ice surface above the sea level, which leads to significant uncertainties over thin ice regimes. The sea ice at the north of Greenland is considered one of the oldest and thickest in the Arctic. However, during late February - early March 2018, a polynya formed north to Greenland due to extra strong southern winds. We focus on the retrieval of sea ice thickness and snow conditions with CryoSat-2 and SMOS during the formation of the polynya. Specifically, we investigate the uncertainty of CryoSat-2 and carry out inter- comparison of sea ice thickness retrieval with SMOS and CryoSat-2/SMOS synergy. Besides, further discussion of retrieval with CryoSat-2 is provided for such scenarios where the mélange of thick ice and newly formed thin ice is present.</p>

‘The last duty of an officer’: Lieutenant de vaisseau Joseph-René Bellot, 1826–1853, in the Franklin Search

Polar Record ◽  
2013 ◽  
Vol 50 (1) ◽  
pp. 1-30 ◽  
Author(s):  
William Barr ◽  
Nadine Forestier-Blazart ◽  
Jean-Claude Forestier-Blazart
Keyword(s):  
East Coast ◽  
The Arctic ◽  
North Coast ◽  
Northwest Passage ◽  
The North ◽  
Integral Component ◽  
Somerset Island

ABSTRACTLieutenant de vaisseau Joseph René Bellot, (1826–1853) participated, as second-in command, in Lady Franklin's private expedition in search of her missing husband on board Prince Albert, under the command of Captain William Kennedy in 1851–1852. Having wintered at Batty Bay on the east coast of Somerset Island, Kennedy and Bellot sledged south in the spring of 1852, to Bellot Strait, which they discovered. Having passed through the strait, they crossed Peel Sound, and continued west across Prince of Wales Island to Ommanney Bay, then back across Prince of Wales Island, north to Cape Walker, and back to Batty Bay via the north coast of Somerset Island and Prince Leopold Harbour. They discovered no trace of the missing Franklin expedition. In 1853 Bellot again volunteered to go to the Arctic, this time as supernumerary on board the supply ship Phoenix, Captain Edward Inglefield. From Beechey Island, Bellot volunteered to carry dispatches north up Wellington Channel to Captain Sir Edward Belcher who was in that vicinity. Having been driven out of sea on an ice-floe, Bellot disappeared during a gale, and it is assumed that he was blown off the ice into the water and was drowned. Memorials to Bellot may be found on Beechey Island, at Greenwich, England and at Rochefort, France, but probably the most enduring memorial to him is the name ‘Bellot Strait’, applied by Kennedy to the narrow strait between Somerset Island and Boothia Peninsula which represents an integral component of one variant of the northwest passage.

Mertvaya Doroga – a railroad as the backbone of Soviet defence in the Arctic, 1943–54

Polar Record ◽  
2001 ◽  
Vol 37 (200) ◽  
pp. 49-54
Author(s):  
Florian Mildenberger
Keyword(s):  
World War Ii ◽  
The Arctic ◽  
North Coast ◽  
World War ◽  
Secret Police ◽  
The Urals ◽  
Northern Urals ◽  
The North

AbstractDuring World War II, the threat of a German invasion along the north coast of Siberia led to the Soviet High Command developing a plan to build a railroad through the Urals to the port of Salekhard and beyond. Following the War, these plans were reworked to defend against the threat of American aggression. The ‘Mertvaya Doroga’ or great Stalin railroad or polarmagistral was intended to run from Chum, a small station on the Vorkuta railway, through the northern Urals to Salekhard and from there through Nadym to Igarka and Noril'sk. A second railway was to go from Vorkuta to the port of Amderma, while a third included a great net of railroads around Arkhangel'sk. Slave labour was used to construct these railroads, but despite massive programmes run by the Soviet secret police, the railroads were never completed or efficiently constructed. The death of Stalin in 1953 signaled the end of the construction of the Arctic railroads.

scholarly journals Lower Palaeozoic geology of the western part of the North Greenland fold belt

1966 ◽  
Vol 11 ◽  
pp. 11-15
Author(s):  
P.R Dawes
Keyword(s):  
The Arctic ◽  
North Coast ◽  
Northern Coast ◽  
Fold Belt ◽  
North West ◽  
The North ◽  
Lower Palaeozoic ◽  
Inland Ice ◽  
Insight Into ◽  
North Greenland

In the summers 1965 and 1966 reconnaissance mapping of 10 000 km2 of the rarely visited north coast of North Greenland was carried out. In 1965 the investigations were restricted to Hall Land (fig. 3) with a view of obtaining an insight into the stratigraphy of the Ordovician-Silurian succession, while in 1966 work centred on Nyeboe Land and Hendrik Island with cursory exammation of the north-west coast of Wulff Land and the islands in Sherard Osborn Fjord. Both the unfolded rocks of the south towards the Inland Ice and the folded rocks of the northern coast bordering the Robeson Channel and the Arctic Ocean were studied and in the two summers a broad view of the western part of the North Greenland fold belt i. e. west of Peary Land, has been obained.

scholarly journals Upper Pleistocene and Holocene marine deposits and faunas on the north coast of Nûgssuaq, West Greenland

1981 ◽  
Vol 140 ◽  
pp. 1-107
Author(s):  
L.A Símonarson
Keyword(s):  
The Arctic ◽  
North Coast ◽  
Last Interglacial ◽  
Quaternary Deposits ◽  
West Greenland ◽  
Marine Deposits ◽  
The North ◽  
The Rich ◽  
Delta Slope ◽  
Rich Fauna

Field relations and the composition of the Quaternary molluscan and barnacle faunas at Pátorfik, Kûtsiaq and Sarfâgfik on the north coast of Nûgssuaq, West Greenland, are described. The marine Quaternary deposits at Pátorfik are older than 35 000 years. The lower part of the deposits seems to represent a prodelta environment, whereas the middle and upper parts apparently correspond to a delta slope. The rich fauna and the field relations differ essentially from what we know from other localities in Greenland where Late Wisconsian or Holocene marine fossiliferous deposits have been found. The faunal composition indicates prevailing water temperatures during deposition similar to those at the boundary between the arctic and boreal faunal regions today and somewhat higher than those in Umanak Fjord at present. It is suggested that the Pátorfik deposits were formed during the last interglacial stage (Sangamon/Eemian). The marine beds at Kûtsiaq and Sarfâgfik are of Early Holocene ages and apparently represent delta deposits.

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