scholarly journals Quantifying the Mass Balance of Ice Caps on Severnaya Zemlya, Russian High Arctic. I: Climate and Mass Balance of the Vavilov Ice Cap

2006 ◽  
Vol 38 (1) ◽  
pp. 1-12 ◽  
Author(s):  
R. P. Bassford ◽  
M. J. Siegert ◽  
J. A. Dowdeswell ◽  
J. Oerlemans ◽  
A. F. Glazovsky ◽  
...  
Keyword(s):  
Mass Balance ◽  
High Arctic ◽  
Ice Caps ◽  
Ice Cap ◽  
Severnaya Zemlya

scholarly journals Mass balance of glaciers in the Queen Elizabeth Islands, Nunavut, Canada

2005 ◽  
Vol 42 ◽  
pp. 417-423 ◽  
Author(s):  
Roy M. Koerner
Keyword(s):  
Mass Balance ◽  
High Arctic ◽  
Canadian High Arctic ◽  
Laser Altimetry ◽  
Northeast Section ◽  
Ice Caps ◽  
Laser Measurements ◽  
Devon Island ◽  
Ice Cap ◽  
Devon Ice Cap

AbstractMass-balance measurements began in the Canadian High Arctic in 1959. This paper considers the >40 years of measurements made since then, principally on two stagnant ice caps (on Meighen and Melville Islands), parts of two ice caps (the northeast section of Agassiz Ice Cap on northern Ellesmere Island and the northwest part of Devon Ice Cap on Devon Island) and two glaciers (White and Baby Glaciers, Axel Heiberg Island). The results show continuing negative balances. All the glaciers and ice caps except Meighen Ice Cap show weak but significant trends with time towards increasingly negative balances. Meighen Ice Cap may owe its lack of a trend to a cooling feedback from the increasingly open Arctic Ocean nearby (Johannessen and others, 1995). Feedback from this ocean has been shown to be the main cause of this ice cap’s growth and persistence at such a low elevation of <300 ma.s.l. (Alt, 1979). There may be a similar feedback in the lower elevations on Sverdrup Glacier which drains the northwest sector of Devon Ice Cap. The ablation rates there have not increased to the same extent as they have at higher elevations on the same glacier. Although evidence from the meteorological stations in the area shows that the eastern Arctic has either been cooling or has shown no change on an annual basis between 1950 and 1998, the same records show that the summers are showing a slight warming (Zhang and others, 2000). The summer warming, although slight (<1.0˚C over 48 years), is the cause of the weak trend to increasingly negative balances. This is because the mass-balance variability is dominated by the year-to-year variations in the summer balance; there is a very low variability, and no trend over time even within sections of the time series, of the winter balance of the various ice caps and glaciers. Repeat laser altimetry of ice caps by NASA for the period 1995–2000 over most of the ice caps in the Canadian Arctic Archipelago (Abdalati and others, 2004) has shown that the ablation zones are thinning while the accumulation zones show either a slight thickening or very little elevation change. Laser altimetry is revealing similar patterns of change in Greenland (Krabill and others, 2000) and Svalbard (Bamber and others, 2004). The thickening of the accumulation zones in the Canadian case may be due to higher accumulation rates, not just between the two years of laser measurements, but over a period substantially longer than the >40 years of ground-based measurements.

scholarly journals Dynamic instability of marine-terminating glacier basins of Academy of Sciences Ice Cap, Russian High Arctic

2012 ◽  
Vol 53 (60) ◽  
pp. 193-201 ◽  
Author(s):  
Geir Moholdt ◽  
Torborg Heid ◽  
Toby Benham ◽  
Julian A. Dowdeswell
Keyword(s):  
Mass Balance ◽  
Dynamic Instability ◽  
High Arctic ◽  
Surface Velocity ◽  
Ice Streams ◽  
Ice Caps ◽  
Ice Cap ◽  
Ice Stream ◽  
Almost All ◽  
Academy Of Sciences

AbstractIce sheets and smaller ice caps appear to behave in dynamically similar ways; both contain slow-moving ice that is probably frozen to the bed, interspersed with fast-flowing ice streams and outlet glaciers that terminate into the ocean. Academy of Sciences Ice Cap (Akademii Nauk ice cap; 5570 km2), Severnaya Zemlya, Russian High Arctic, provides a clear example of this varied flow regime. We have combined satellite measurements of elevation change and surface velocity to show that variable ice-stream dynamics dominate the mass balance of the ice cap. Since 1988, the ice cap has lost 58±16 Gt of ice, corresponding to ~3% of its mass or 0.16mm of sea-level rise. The climatic mass balance is estimated to be close to zero, and terminus positions have remained stable to within a few kilometers, implying that almost all mass loss has occurred through iceberg calving. The ice-cap calving rate increased from ~0.6 Gt a–1 in 1995 to ~3.0 Gt a–1 in 2000–02, but has recently decreased to ~1.4 Gt a–1 due to a likely slowdown of the largest ice stream. Such highly variable calving rates have not been reported before from High Arctic ice caps, suggesting that these ice masses may be less stable than previously thought.

scholarly journals Local surface mass-balance reconstruction from a tephra layer – a case study on the northern slope of Mýrdalsjökull, Iceland

2016 ◽  
Vol 63 (237) ◽  
pp. 79-87 ◽  
Author(s):  
CHRISTOPH MAYER ◽  
JULIA JAENICKE ◽  
ASTRID LAMBRECHT ◽  
LUDWIG BRAUN ◽  
CHRISTOF VÖLKSEN ◽  
...  
Keyword(s):  
Mass Balance ◽  
Volcanic Eruptions ◽  
Surface Mass Balance ◽  
Ablation Zone ◽  
Tephra Layer ◽  
Surface Geometry ◽  
High Accumulation ◽  
Surface Mass ◽  
Ice Caps ◽  
Ice Cap

ABSTRACTMost Icelandic glaciers show high-accumulation rates during winter and strong surface melting during summer. Although it is difficult to establish and maintain mass-balance programs on these glaciers, mass-balance series do exist for several of the ice caps (Björnsson and others, 2013). We make use of the frequent volcanic eruptions in Iceland, which cause widespread internal tephra layers in the ice caps, to reconstruct the surface mass balance (SMB) in the ablation zone. This method requires information about surface geometry and ice velocity, derived from remote-sensing information. In addition, the emergence angle of the tephra layer needs to be known. As a proof-of-concept, we utilize a prominent tephra layer of the Mýrdalsjökull Ice Cap to infer local SMB estimates in the ablation area back to 1988. Using tephra-layer outcrop locations across the glacier at different points in time it is possible to determine local mass changes (loss and redistribution) for a large part of the ablation zone, without the use of historic elevation models, which often are not available.

scholarly journals Mass Balance of Two High Arctic Plateau Ice Caps

1987 ◽  
Vol 33 (113) ◽  
pp. 123-128 ◽  
Author(s):  
Raymond S. Bradley ◽  
Mark C. Serreze
Keyword(s):  
Mass Balance ◽  
High Arctic ◽  
Climatic Conditions ◽  
Ellesmere Island ◽  
Equilibrium Line ◽  
Ice Caps ◽  
Mass Losses ◽  
North Eastern ◽  
Contemporary Climate ◽  
Significant Mass

AbstractMass-balance measurements have been renewed on two small ice caps on north-eastern Ellesmere Island. Original stake networks were established in 1972 and 1976. Since then, both ice caps have experienced significant mass losses averaging –70 to –140 kg m−2a−1. They have also decreased in area. The equilibrium line in this area has averaged around 1150 m for the last decade or so. The ice caps are remnants of former climatic conditions and are out of equilibrium with contemporary climate.

scholarly journals Surge-type glaciers in the Russian High Arctic identified from digital satellite imagery

1997 ◽  
Vol 43 (145) ◽  
pp. 489-494 ◽  
Author(s):  
Julian A. Dowdeswell ◽  
Meredith Williams
Keyword(s):  
Thermal Structure ◽  
High Arctic ◽  
Drainage Basins ◽  
Novaya Zemlya ◽  
Ice Cap ◽  
Franz Josef Land ◽  
Covered Area ◽  
Glacier Surges ◽  
Severnaya Zemlya ◽  
Summer Time

AbstractLandsat digital imagery was used to search the island archipelagos of Franz Josef Land, Severnaya Zemlya and Novaya Zemlya, Russian High Arctic, for the presence of looped moraines characteristic of past glacier surges. The imagery provides almost complete summer-time coverage of the 60 000 km2 of ice in these islands. very few surge-type glaciers are identified: none in Franz Josef Land, three in Novaya Zemlya and two on Severnaya Zemlya. This contrasts greatly with Svalbard (ice-covered area 36 600 km2), to the west, where 36% of glaciers and ice-cap drainage basins are inferred to surge. The strong climatic gradient across the Eurasian High Arctic, with decreasing temperature and moisture eastward, may provide a gross control on this pattern through colder glacier thermal structure, limiting basal drainage on the thinner ice masses in particular.

scholarly journals Equilibrium-Line Altitudes, Mass Balance, and July Freezing-Level Heights in the Canadian High Arctic

1975 ◽  
Vol 14 (71) ◽  
pp. 267-274 ◽  
Author(s):  
R. S. Bradley
Keyword(s):  
Mass Balance ◽  
High Arctic ◽  
Equilibrium Line ◽  
Canadian High Arctic ◽  
North West ◽  
Freezing Level ◽  
Ice Cap ◽  
The North ◽  
Devon Ice Cap ◽  
Axel Heiberg Island

Equilibrium-line altitudes on the White Glacier, Axel Heiberg Island, and the north-west sector of the Devon Ice Cap are shown to be closely related to mean July freezing-level heights at nearby upper-air weather stations. An inverse relationship between July freezing-level heights and mass balance on the Devon Ice Cap is also shown. Reasons for such correlations are suggested and some limitations of the relationship are outlined. Recent lowering of the freezing level in July is discussed in relation to the theoretical “steady-state” equilibrium-line altitudes in the Canadian high Arctic. It is suggested that positive mass-balance years have predominated over a large part of northern Ellesmere Island and north-central Axel Heiberg Island since 1963, and some glaciological evidence supporting this hypothesis is given.

Glaciers in the High Arctic and recent environmental change

1995 ◽  
Vol 352 (1699) ◽  
pp. 321-334 ◽  
Keyword(s):  
Mass Balance ◽  
Climate Warming ◽  
Meteorological Data ◽  
Ice Cores ◽  
High Arctic ◽  
Ice Age ◽  
Geological Evidence ◽  
Recent Climate ◽  
Severnaya Zemlya ◽  
Energy Balance Approach

High Arctic climate change over the last few hundred years includes the relatively cool Little Ice Age (LIA), followed by warming over the last hundred years or so. Meteorological data from the Eurasian High Arctic (Svalbard, Franz Josef Land, Severnaya Zemlya) and Canadian High Arctic islands are scarce before the mid-20th century, but longer records from Svalbard and Greenland show warming from about 1910-1920. Logs of Royal Navy ships in the Canadian Northwest Passage in the 1850s indicate temperatures cooler by 1-2.5 °C during the LIA. Other evidence of recent trends in High Arctic temperatures and precipitation is derived from ice cores, which show cooler temperatures (by 2-3 °C) for several hundred years before 1900, with high interdecadal variability. The proportion of melt layers in ice cores has also risen over the last 70-130 years, indicating warming. There is widespread geological evidence of glacier retreat in the High Arctic since about the turn of the century linked to the end of the LIA. An exception is the rapid advance of some surge-type ice masses. Mass balance measurements on ice caps in Arctic Canada, Svalbard and Severnaya Zemlya since 1950 show either negative or near-zero net balances, suggesting glacier response to recent climate warming. Glacier-climate links are modelled using an energy balance approach to predict glacier response to possible future climate warming, and cooler LIA temperatures. For Spitsbergen glaciers, a negative shift in mass balance of about 0.5 m a -1 is predicted for a 1 °C warming. A cooling of about 0.6 °C, or a 23% precipitation increase, would produce an approximately zero net mass balance. A ‘greenhouse-induced’ warming of 1 °C in the High Arctic is predicted to produce a global sea-level rise of 0.063 mm a -1 from ice cap melting.

scholarly journals Positive mass balance during the late 20th century on Austfonna, Svalbard, revealed using satellite radar interferometry

2007 ◽  
Vol 46 ◽  
pp. 117-122 ◽  
Author(s):  
Suzanne Bevan ◽  
Adrian Luckman ◽  
Tavi Murray ◽  
Helena Sykes ◽  
Jack Kohler
Keyword(s):  
Climate Change ◽  
Mass Balance ◽  
Radar Interferometry ◽  
The Arctic ◽  
Late 20Th Century ◽  
Ice Caps ◽  
Ice Cap ◽  
Radio Echo Sounding ◽  
Satellite Radar ◽  
Increasing Temperature

AbstractDetermining whether increasing temperature or precipitation will dominate the cryospheric response to climate change is key to forecasting future sea-level rise. The volume of ice contained in the ice caps and glaciers of the Arctic archipelago of Svalbard is small compared with that of the Greenland or Antarctic ice sheets, but is likely to be affected much more rapidly in the short term by climate change. This study investigates the mass balance of Austfonna, Svalbard’s largest ice cap. Equilibrium-line fluxes for the whole ice cap, and for individual drainage basins, were estimated by combining surface velocities measured using satellite radar interferometry with ice thicknesses derived from radio-echo sounding. These fluxes were compared with balance fluxes to reveal that during the 1990s the total mass balance of the accumulation zone was (5.6±2.0)×108m3 a–1. Three basins in the quiescent phase of their surge cycles contributed 75% of this accumulation. The remaining volume may be attributable either to as yet unidentified surge-type glaciers, or to increased precipitation. This result emphasizes the importance of considering the surge dynamics of glaciers when attempting to draw any conclusions on climate change based on snapshot observations of the cryosphere.

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