Articles | Volume 10, issue 3
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Basal buoyancy and fast-moving glaciers: in defense of analytic force balance
C. J. van der Veen
Department of Geography and Atmospheric Science, University of Kansas, 203 Lindley Hall, 1475 Jayhawk Blvd, Lawrence, KS 66045, USA
Related subject area
GlaciersBrief communication: Glacier mapping and change estimation using very high-resolution declassified Hexagon KH-9 panoramic stereo imagery (1971–1984)Modelled 3D calving at Kronebreen, Svalbard, driven by tidal fluctuations and frontal meltBrief communication: Estimating the ice thickness of the Müller Ice Cap to support selection of a drill siteGlacier geometry and flow speed determine how Arctic marine-terminating glaciers respond to lubricated bedsA regionally resolved inventory of High Mountain Asia surge-type glaciers, derived from a multi-factor remote sensing approachGeometric controls of tidewater glacier dynamicsTowards ice-thickness inversion: an evaluation of global digital elevation models (DEMs) in the glacierized Tibetan PlateauRecord summer rains in 2019 led to massive loss of surface and cave ice in SE EuropeEvolution of the firn pack of Kaskawulsh Glacier, Yukon: meltwater effects, densification, and the development of a perennial firn aquiferA simple parametrization of mélange buttressing for calving glaciersFull crystallographic orientation (c and a axes) of warm, coarse-grained ice in a shear-dominated setting: a case study, Storglaciären, SwedenA decade of variability on Jakobshavn Isbræ: ocean temperatures pace speed through influence on mélange rigidityContribution of calving to frontal ablation quantified from seismic and hydroacoustic observations calibrated with lidar volume measurementsBrief communication: Updated GAMDAM glacier inventory over high-mountain AsiaIce cliff contribution to the tongue-wide ablation of Changri Nup Glacier, Nepal, central HimalayaEffects of undercutting and sliding on calving: a global approach applied to Kronebreen, SvalbardSurface lowering of the debris-covered area of Kanchenjunga Glacier in the eastern Nepal Himalaya since 1975, as revealed by Hexagon KH-9 and ALOS satellite observationsInitiation of a major calving event on the Bowdoin Glacier captured by UAV photogrammetryCalving localization at Helheim Glacier using multiple local seismic stationsFrontal destabilization of Stonebreen, Edgeøya, SvalbardSpatial variability in mass loss of glaciers in the Everest region, central Himalayas, between 2000 and 2015Diagnosing the decline in climatic mass balance of glaciers in Svalbard over 1957–2014Recent changes in area and thickness of Torngat Mountain glaciers (northern Labrador, Canada)Brief communication: Thinning of debris-covered and debris-free glaciers in a warming climateConcentration, sources and light absorption characteristics of dissolved organic carbon on a medium-sized valley glacier, northern Tibetan Plateau3-D surface properties of glacier penitentes over an ablation season, measured using a Microsoft Xbox KinectRapid glacial retreat on the Kamchatka Peninsula during the early 21st centuryReduced melt on debris-covered glaciers: investigations from Changri Nup Glacier, NepalThe climatic mass balance of Svalbard glaciers: a 10-year simulation with a coupled atmosphere–glacier mass balance modelCorrection of broadband snow albedo measurements affected by unknown slope and sensor tiltsAblation from calving and surface melt at lake-terminating Bridge Glacier, British Columbia, 1984–2013Brief Communication: Global reconstructions of glacier mass change during the 20th century are consistentSurface speed and frontal ablation of Kronebreen and Kongsbreen, NW Svalbard, from SAR offset trackingImproving semi-automated glacier mapping with a multi-method approach: applications in central AsiaArea, elevation and mass changes of the two southernmost ice caps of the Canadian Arctic Archipelago between 1952 and 2014Modelling annual mass balances of eight Scandinavian glaciers using statistical modelsWinter speed-up of quiescent surge-type glaciers in Yukon, CanadaModelling glacier change in the Everest region, Nepal HimalayaThe GAMDAM glacier inventory: a quality-controlled inventory of Asian glaciersClimate regime of Asian glaciers revealed by GAMDAM glacier inventoryA model study of Abrahamsenbreen, a surging glacier in northern SpitsbergenMass changes of Southern and Northern Inylchek Glacier, Central Tian Shan, Kyrgyzstan, during ∼1975 and 2007 derived from remote sensing dataChanges in the southeast Vatnajökull ice cap, Iceland, between ~ 1890 and 2010Spatial patterns in glacier characteristics and area changes from 1962 to 2006 in the Kanchenjunga–Sikkim area, eastern HimalayaSeasonal changes in surface albedo of Himalayan glaciers from MODIS data and links with the annual mass balanceGlacier-surge mechanisms promoted by a hydro-thermodynamic feedback to summer meltUAV photogrammetry and structure from motion to assess calving dynamics at Store Glacier, a large outlet draining the Greenland ice sheetQuantifying mass balance processes on the Southern Patagonia IcefieldAre seasonal calving dynamics forced by buttressing from ice mélange or undercutting by melting? Outcomes from full-Stokes simulations of Store Glacier, West GreenlandEstimating the volume of glaciers in the Himalayan–Karakoram region using different methods
Sajid Ghuffar, Owen King, Grégoire Guillet, Ewelina Rupnik, and Tobias Bolch
The Cryosphere, 17, 1299–1306,Short summary
The panoramic cameras (PCs) on board Hexagon KH-9 satellite missions from 1971–1984 captured very high-resolution stereo imagery with up to 60 cm spatial resolution. This study explores the potential of this imagery for glacier mapping and change estimation. The high resolution of KH-9PC leads to higher-quality DEMs which better resolve the accumulation region of glaciers in comparison to the KH-9 mapping camera, and KH-9PC imagery can be useful in several Earth observation applications.
Felicity Alice Holmes, Eef van Dongen, Riko Noormets, Michał Pętlicki, and Nina Kirchner
The Cryosphere Discuss.,
Revised manuscript accepted for TCShort summary
Glaciers which end in bodies of water can lose mass through melting below the waterline, as well as by the breaking off of icebergs. We use a numerical model to simulate the breaking off of icebergs at Kronebreen, a glacier in Svalbard, and find that both melting below the waterline and tides are important for iceberg production. In addition, we compare the modelled glacier front to observations and show that melting below the waterline can lead to undercuts of up to around 25 m.
Ann-Sofie Priergaard Zinck and Aslak Grinsted
The Cryosphere, 16, 1399–1407,Short summary
The Müller Ice Cap will soon set the scene for a new drilling project. To obtain an ice core with stratified layers and a good time resolution, thickness estimates are necessary for the planning. Here we present a new and fast method of estimating ice thicknesses from sparse data and compare it to an existing ice flow model. We find that the new semi-empirical method is insensitive to mass balance, is computationally fast, and provides good fits when compared to radar measurements.
The Cryosphere, 16, 1431–1445,Short summary
A glacier can speed up when surface water reaches the glacier's bottom via crevasses and reduces sliding friction. This paper builds up a physical model and finds that thick and fast-flowing glaciers are sensitive to this friction disruption. The data from Greenland and Austfonna (Svalbard) glaciers over 20 years support the model prediction. To estimate the projected sea-level rise better, these sensitive glaciers should be frequently monitored for potential future instabilities.
Gregoire Guillet, Owen King, Mingyang Lv, Sajid Ghuffar, Douglas Benn, Duncan Quincey, and Tobias Bolch
The Cryosphere, 16, 603–623,Short summary
Surging glaciers show cyclical changes in flow behavior – between slow and fast flow – and can have drastic impacts on settlements in their vicinity. One of the clusters of surging glaciers worldwide is High Mountain Asia (HMA). We present an inventory of surging glaciers in HMA, identified from satellite imagery. We show that the number of surging glaciers was underestimated and that they represent 20 % of the area covered by glaciers in HMA, before discussing new physics for glacier surges.
Thomas Frank, Henning Åkesson, Basile de Fleurian, Mathieu Morlighem, and Kerim H. Nisancioglu
The Cryosphere, 16, 581–601,Short summary
The shape of a fjord can promote or inhibit glacier retreat in response to climate change. We conduct experiments with a synthetic setup under idealized conditions in a numerical model to study and quantify the processes involved. We find that friction between ice and fjord is the most important factor and that it is possible to directly link ice discharge and grounding line retreat to fjord topography in a quantitative way.
Wenfeng Chen, Tandong Yao, Guoqing Zhang, Fei Li, Guoxiong Zheng, Yushan Zhou, and Fenglin Xu
The Cryosphere, 16, 197–218,Short summary
A digital elevation model (DEM) is a prerequisite for estimating regional glacier thickness. Our study first compared six widely used global DEMs over the glacierized Tibetan Plateau by using ICESat-2 (Ice, Cloud and land Elevation Satellite) laser altimetry data. Our results show that NASADEM had the best accuracy. We conclude that NASADEM would be the best choice for ice-thickness estimation over the Tibetan Plateau through an intercomparison of four ice-thickness inversion models.
Aurel Perşoiu, Nenad Buzjak, Alexandru Onaca, Christos Pennos, Yorgos Sotiriadis, Monica Ionita, Stavros Zachariadis, Michael Styllas, Jure Kosutnik, Alexandru Hegyi, and Valerija Butorac
The Cryosphere, 15, 2383–2399,Short summary
Extreme precipitation events in summer 2019 led to catastrophic loss of cave and surface ice in SE Europe at levels unprecedented during the last century. The projected continuous warming and increase in precipitation extremes could pose an additional threat to glaciers in southern Europe, resulting in a potentially ice-free SE Europe by the middle of the next decade (2035 CE).
Naomi E. Ochwat, Shawn J. Marshall, Brian J. Moorman, Alison S. Criscitiello, and Luke Copland
The Cryosphere, 15, 2021–2040,Short summary
In May 2018 we drilled into Kaskawulsh Glacier to study how it is being affected by climate warming and used models to investigate the evolution of the firn since the 1960s. We found that the accumulation zone has experienced increased melting that has refrozen as ice layers and has formed a perennial firn aquifer. These results better inform climate-induced changes on northern glaciers and variables to take into account when estimating glacier mass change using remote-sensing methods.
Tanja Schlemm and Anders Levermann
The Cryosphere, 15, 531–545,Short summary
Ice loss from Greenland and Antarctica is often cloaked by a mélange of icebergs and sea ice. Here we provide a simple method to parametrize the resulting back stress on the ice flow for large-scale projection models.
Morgan E. Monz, Peter J. Hudleston, David J. Prior, Zachary Michels, Sheng Fan, Marianne Negrini, Pat J. Langhorne, and Chao Qi
The Cryosphere, 15, 303–324,Short summary
We present full crystallographic orientations of warm, coarse-grained ice deformed in a shear setting, enabling better characterization of how crystals in glacial ice preferentially align as ice flows. A commonly noted c-axis pattern, with several favored orientations, may result from bias due to overcounting large crystals with complex 3D shapes. A new sample preparation method effectively increases the sample size and reduces bias, resulting in a simpler pattern consistent with the ice flow.
Ian Joughin, David E. Shean, Benjamin E. Smith, and Dana Floricioiu
The Cryosphere, 14, 211–227,Short summary
Jakobshavn Isbræ, considered to be Greenland's fastest glacier, has varied its speed and thinned dramatically since the 1990s. Here we examine the glacier's behaviour over the last decade to better understand this behaviour. We find that when the floating ice (mélange) in front of the glacier freezes in place during the winter, it can control the glacier's speed and thinning rate. A recently colder ocean has strengthened this mélange, allowing the glacier to recoup some of its previous losses.
Andreas Köhler, Michał Pętlicki, Pierre-Marie Lefeuvre, Giuseppa Buscaino, Christopher Nuth, and Christian Weidle
The Cryosphere, 13, 3117–3137,Short summary
Ice loss at the front of glaciers can be observed with high temporal resolution using seismometers. We combine seismic and underwater sound measurements of iceberg calving at Kronebreen, a glacier in Svalbard, with laser scanning of the glacier front. We develop a method to determine calving ice loss directly from seismic and underwater calving signals. This allowed us to quantify the contribution of calving to the total ice loss at the glacier front, which also includes underwater melting.
The Cryosphere, 13, 2043–2049,Short summary
The Glacier Area Mapping for Discharge from the Asian Mountains (GAMDAM) glacier inventory was updated to revise the underestimated glacier area in the first version. The total number and area of glaciers are 134 770 and 100 693 ± 11 790 km2 from 453 Landsat images, which were carefully selected for the period from 1990 to 2010, to avoid mountain shadow, cloud cover, and seasonal snow cover.
Fanny Brun, Patrick Wagnon, Etienne Berthier, Joseph M. Shea, Walter W. Immerzeel, Philip D. A. Kraaijenbrink, Christian Vincent, Camille Reverchon, Dibas Shrestha, and Yves Arnaud
The Cryosphere, 12, 3439–3457,Short summary
On debris-covered glaciers, steep ice cliffs experience dramatically enhanced melt compared with the surrounding debris-covered ice. Using field measurements, UAV data and submetre satellite imagery, we estimate the cliff contribution to 2 years of ablation on a debris-covered tongue in Nepal, carefully taking into account ice dynamics. While they occupy only 7 to 8 % of the tongue surface, ice cliffs contributed to 23 to 24 % of the total tongue ablation.
Dorothée Vallot, Jan Åström, Thomas Zwinger, Rickard Pettersson, Alistair Everett, Douglas I. Benn, Adrian Luckman, Ward J. J. van Pelt, Faezeh Nick, and Jack Kohler
The Cryosphere, 12, 609–625,Short summary
This paper presents a new perspective on the role of ice dynamics and ocean interaction in glacier calving processes applied to Kronebreen, a tidewater glacier in Svalbard. A global modelling approach includes ice flow modelling, undercutting estimation by a combination of glacier energy balance and plume modelling as well as calving by a discrete particle model. We show that modelling undercutting is necessary and calving is influenced by basal friction velocity and geometry.
Damodar Lamsal, Koji Fujita, and Akiko Sakai
The Cryosphere, 11, 2815–2827,Short summary
This study presents the geodetic mass balance of Kanchenjunga Glacier, a heavily debris-covered glacier in the easternmost Nepal Himalaya, between 1975 and 2010 using high-resolution DEMs. The rate of elevation change positively correlates with elevation and glacier velocity, and significant surface lowering is observed at supraglacial ponds. A difference in pond density would strongly affect the different geodetic mass balances of the Kanchenjunga and Khumbu glaciers.
Guillaume Jouvet, Yvo Weidmann, Julien Seguinot, Martin Funk, Takahiro Abe, Daiki Sakakibara, Hakime Seddik, and Shin Sugiyama
The Cryosphere, 11, 911–921,Short summary
In this study, we combine UAV (unmanned aerial vehicles) images taken over the Bowdoin Glacier, north-western Greenland, and a model describing the viscous motion of ice to track the propagation of crevasses responsible for the collapse of large icebergs at the glacier-ocean front (calving). This new technique allows us to explain the systematic calving pattern observed in spring and summer of 2015 and anticipate a possible rapid retreat in the future.
M. Jeffrey Mei, David M. Holland, Sridhar Anandakrishnan, and Tiantian Zheng
The Cryosphere, 11, 609–618,Short summary
We determine a method to locate calving at Helheim Glacier. By using local seismometers, we are able to find the calving location at a much higher precision than previous studies. The signal–onset time differences at four local seismic stations are used to determine possible seismic-wave origins. We present a catalogue of 12 calving events from 2014 to 2015, which shows that calving preferentially happens at the northern end of Helheim Glacier, which will help to constrain models of calving.
Tazio Strozzi, Andreas Kääb, and Thomas Schellenberger
The Cryosphere, 11, 553–566,Short summary
The strong atmospheric warming observed since the 1990s in polar regions requires quantifying the contribution to sea level rise of glaciers and ice caps, but for large areas we do not have much information on ice dynamic fluctuations. The recent increase in satellite data opens up new possibilities to monitor ice flow. We observed over Stonebreen on Edgeøya (Svalbard) a strong increase since 2012 in ice surface velocity along with a decrease in volume and an advance in frontal extension.
Owen King, Duncan J. Quincey, Jonathan L. Carrivick, and Ann V. Rowan
The Cryosphere, 11, 407–426,Short summary
We used multiple digital elevation models to quantify melt on 32 glaciers in the Everest region of the Himalayas. We examined whether patterns of melt differed depending on whether the glacier terminated on land or in water. We found that glaciers terminating in large lakes had the highest melt rates, but that those terminating in small lakes had comparable melt rates to those terminating on land. We carried out this research because Himalayan people are highly dependent on glacier meltwater.
Torbjørn Ims Østby, Thomas Vikhamar Schuler, Jon Ove Hagen, Regine Hock, Jack Kohler, and Carleen H. Reijmer
The Cryosphere, 11, 191–215,Short summary
We present modelled climatic mass balance for all glaciers in Svalbard for the period 1957–2014 at 1 km resolution using a coupled surface energy balance and snowpack model, thereby closing temporal and spatial gaps in direct and geodetic mass balance estimates. Supporting previous studies, our results indicate increased mass loss over the period. A detailed analysis of the involved energy fluxes reveals that increased mass loss is caused by atmospheric warming further amplified by feedbacks.
Nicholas E. Barrand, Robert G. Way, Trevor Bell, and Martin J. Sharp
The Cryosphere, 11, 157–168,Short summary
This paper provides a comprehensive assessment of the state of small glaciers in the Canadian province of Labrador. These glaciers, the last in continental northeast North America, exist in heavily shaded locations within the remote Torngat Mountains National Park. Fieldwork, and airborne and spaceborne remote-sensing analyses were used to measure regional glacier area changes and individual glacier thinning rates. These results were then linked to trends in prevailing climatic conditions.
The Cryosphere, 11, 133–138,Short summary
Measurements of debris-covered and debris-free glaciers in the Himalaya-Karakoram show similar decadal scale thinning, despite a suppression of melt under the debris. Using physical arguments, supported by simulations of 1-D idealised glaciers, we analyse the evolution of thinning rates on both glacier types under a warming climate. The dynamics of the emergence velocity profile control the thinning rate evolution in general and lead to the observed trends in the thinning rate data.
Fangping Yan, Shichang Kang, Chaoliu Li, Yulan Zhang, Xiang Qin, Yang Li, Xiaopeng Zhang, Zhaofu Hu, Pengfei Chen, Xiaofei Li, Bin Qu, and Mika Sillanpää
The Cryosphere, 10, 2611–2621,Short summary
DOC release of Laohugou Glacier No. 12 was 192 kg km−2 yr−1, of which 43.2 % could be decomposed and return to atmosphere as CO2 within 28 days, producing positive feedback in the warming process and influencing downstream ecosystems. Radiative forcing of snow pit DOC was calculated to be 0.43 W m−2, accounting for about 10 % of the radiative forcing caused by BC. Therefore, DOC is also a light-absorbing agent in glacierized regions, influencing the albedo of glacier surface and glacier melting.
Lindsey I. Nicholson, Michał Pętlicki, Ben Partan, and Shelley MacDonell
The Cryosphere, 10, 1897–1913,Short summary
An Xbox Kinect sensor was used as a close-range surface scanner to produce the first accurate 3D surface models of spikes of snow and ice (known as penitentes) that develop in cold, dry, sunny conditions. The data collected show how penitentes develop over time and how they affect the surface roughness of a glacier. These surface models are useful inputs to modelling studies of how penitentes alter energy exchanges between the atmosphere and the surface and how this affects meltwater production.
Colleen M. Lynch, Iestyn D. Barr, Donal Mullan, and Alastair Ruffell
The Cryosphere, 10, 1809–1821,Short summary
Early 21st century changes in the extent of glaciers on Kamchatka were manually mapped from satellite imagery. This revealed 673 glaciers, with a total surface area of 775.7 ± 27.9 km2 in 2000, and 738 glaciers, with a total area of 592.9 ± 20.4 km2 in 2014. This ~24 % decline in glacier surface area is considered to reflect variations in climate (particularly rising summer temperatures), though the response of individual glaciers was likely modulated by other (non-climatic) factors.
Christian Vincent, Patrick Wagnon, Joseph M. Shea, Walter W. Immerzeel, Philip Kraaijenbrink, Dibas Shrestha, Alvaro Soruco, Yves Arnaud, Fanny Brun, Etienne Berthier, and Sonam Futi Sherpa
The Cryosphere, 10, 1845–1858,Short summary
Approximately 25 % of the glacierized area in the Everest region is covered by debris, yet the surface mass balance of these glaciers has not been measured directly. From terrestrial photogrammetry and unmanned aerial vehicle (UAV) methods, this study shows that the ablation is strongly reduced by the debris cover. The insulating effect of the debris cover has a larger effect on total mass loss than the enhanced ice ablation due to supraglacial ponds and exposed ice cliffs.
Kjetil S. Aas, Thorben Dunse, Emily Collier, Thomas V. Schuler, Terje K. Berntsen, Jack Kohler, and Bartłomiej Luks
The Cryosphere, 10, 1089–1104,Short summary
A high-resolution, coupled atmosphere--climatic mass balance (CMB) model is applied to Svalbard for the period 2003 to 2013. The mean CMB during this period is negative but displays large spatial and temporal variations. Comparison with observations on different scales shows a good overall model performance except for one particular glacier, where wind strongly affects the spatial patterns of CMB. The model also shows considerable sensitivity to model resolution, especially on local scales.
Ursula Weiser, Marc Olefs, Wolfgang Schöner, Gernot Weyss, and Bernhard Hynek
The Cryosphere, 10, 775–790,Short summary
Geometric effects induced by tilt errors lead to erroneous measurement of snow albedo. These errors are corrected where tilts of sensors and slopes are unknown. Atmospheric parameters are taken from a nearby reference measurement or a radiation model. The developed model is fitted to the measured data to determine tilts and directions which vary daily due to changing atmospheric conditions and snow cover. The results show an obvious under- or overestimation of albedo depending on the slope direction.
M. Chernos, M. Koppes, and R. D. Moore
The Cryosphere, 10, 87–102,Short summary
Ice loss from calving and surface melt is estimated at lake-terminating Bridge Glacier, British Columbia, Canada, from 1984 to 2013. Since the glacier's terminus began to float in 1991, calving has accounted for 10-25% of the glacier's total ice loss below the ELA. Overall, calving is a relatively small component of ice loss and is expected to decrease in importance in the future as the glacier retreats onto dry land. Hence, projections of future retreat remain dependent on climatic conditions.
B. Marzeion, P. W. Leclercq, J. G. Cogley, and A. H. Jarosch
The Cryosphere, 9, 2399–2404,Short summary
We show that estimates of global glacier mass change during the 20th century, obtained from glacier-length-based reconstructions and from a glacier model driven by gridded climate observations are now consistent with each other and also with an estimate for the years 2003-2009 that is mostly based on remotely sensed data. This consistency is found throughout the entire common periods of the respective data sets. Inconsistencies of reconstructions and observations persist on regional scales.
T. Schellenberger, T. Dunse, A. Kääb, J. Kohler, and C. H. Reijmer
The Cryosphere, 9, 2339–2355,Short summary
Kronebreen and Kongsbreen are among the fastest flowing glaciers on Svalbard, and surface speeds reached up to 3.2m d-1 at Kronebreen in summer 2013 and 2.7m d-1 at Kongsbreen in late autumn 2012 as retrieved from SAR satellite data. Both glaciers retreated significantly during the observation period, Kongsbreen up to 1800m or 2.5km2 and Kronebreen up to 850m or 2.8km2. Both glaciers are important contributors to the total dynamic mass loss from the Svalbard archipelago.
T. Smith, B. Bookhagen, and F. Cannon
The Cryosphere, 9, 1747–1759,Short summary
We describe and apply a newly developed glacial mapping algorithm which uses spectral, topographic, velocity, and spatial data to quickly and accurately map glacial extents over a wide area. This method maps both clean glacier ice and debris-covered glacier tongues across diverse topographic, land cover, and spectral settings using primarily open-source tools.
C. Papasodoro, E. Berthier, A. Royer, C. Zdanowicz, and A. Langlois
The Cryosphere, 9, 1535–1550,Short summary
Located at the far south (~62.5° N) of the Canadian Arctic, Grinnell and Terra Nivea Ice Caps are good climate proxies in this scarce data region. Multiple data sets (in situ, airborne and spaceborne) reveal changes in area, elevation and mass over the past 62 years. Ice wastage sharply accelerated during the last decade for both ice caps, as illustrated by the strongly negative mass balance of Terra Nivea over 2007-2014 (-1.77 ± 0.36 m a-1 w.e.). Possible climatic drivers are also discussed.
M. Trachsel and A. Nesje
The Cryosphere, 9, 1401–1414,Short summary
We employ statistical models to model annual glacier mass balances of eight Scandinavian glaciers as function of summer temperature and winter precipitation. Relative importances of winter precipitation and summer temperature vary in time. Relative importances are influenced by AMO and NAO.
T. Abe and M. Furuya
The Cryosphere, 9, 1183–1190,Short summary
Whereas glacier surge is known to often initiate in winter, we show significant winter speed-up signals in the upstream region even at quiescent surge-type glaciers in Yukon, Canada. Moreover, the winter speed-up region expanded from upstream to downstream. Given the absence of surface meltwater input in winter, we speculate the presence of englacial water storage that does not directly connect to the surface, yet can promote basal sliding through increased water pressure.
J. M. Shea, W. W. Immerzeel, P. Wagnon, C. Vincent, and S. Bajracharya
The Cryosphere, 9, 1105–1128,Short summary
A glacier mass balance and redistribution model that integrates field observations and downscaled climate fields is developed to examine glacier sensitivity to future climate in the Everest region of Nepal. The modelled sensitivity of glaciers to future climate change is high, and glacier mass loss is sustained through the 21st century for both middle- and high-emission scenarios. Projected temperature increases will expose large glacier areas to melt and reduce snow accumulations.
T. Nuimura, A. Sakai, K. Taniguchi, H. Nagai, D. Lamsal, S. Tsutaki, A. Kozawa, Y. Hoshina, S. Takenaka, S. Omiya, K. Tsunematsu, P. Tshering, and K. Fujita
The Cryosphere, 9, 849–864,Short summary
We present a new glacier inventory for high-mountain Asia named “Glacier Area Mapping for Discharge from the Asian Mountains” (GAMDAM). Glacier outlines were delineated manually using 356 Landsat ETM+ scenes in 226 path-row sets from the period 1999–2003, in conjunction with a digital elevation model and high-resolution Google EarthTM imagery. Our GAMDAM Glacier Inventory includes 87,084 glaciers covering a total area of 91,263 ± 13,689 km2 throughout high-mountain Asia.
A. Sakai, T. Nuimura, K. Fujita, S. Takenaka, H. Nagai, and D. Lamsal
The Cryosphere, 9, 865–880,Short summary
Among meteorological elements, precipitation has a large spatial variability and less observation, particularly in high-mountain Asia, although precipitation in mountains is an important parameter for hydrological circulation. Based on the GAMDAM glacier inventory, we estimated precipitation contributing to glacier mass at the median elevation of glaciers, which is presumed to be at equilibrium-line altitude, by tuning adjustment parameters of precipitation.
J. Oerlemans and W. J. J. van Pelt
The Cryosphere, 9, 767–779,Short summary
Many glaciers on Svalbard are surging glaciers. A surge is a rapid advance of the glacier snout during a few years, followed by a long period of quiescence. During the surge ice flows to lower terrain and experiences higher melt rates in summer. Here we investigate the impact of surging on the long-term effects of climate warming. We have modelled Abrahamsenbreen in northern Spitsbergen as a typical case. We show that surges tend to accelerate glacier retreat when temperature increases.
D. H. Shangguan, T. Bolch, Y. J. Ding, M. Kröhnert, T. Pieczonka, H. U. Wetzel, and S. Y. Liu
The Cryosphere, 9, 703–717,Short summary
Glacier velocity, glacier area, surface elevation and mass changes of the Southern and Northern Inylchek Glacier were investigated by using multi-temporal space-borne data sets. The mass balance of both SIG and NIG was negative(-0.43 ± 0.10 m w.e. a-1 and -0.25 ± 0.10 m w.e. a-1) from ~1975 to 2007. The thinning at the lake dam was higher, likely caused by calving into Lake Merzbacher. Thus, glacier thinning and glacier flow are significantly influenced by the lake.
H. Hannesdóttir, H. Björnsson, F. Pálsson, G. Aðalgeirsdóttir, and Sv. Guðmundsson
The Cryosphere, 9, 565–585,
A. E. Racoviteanu, Y. Arnaud, M. W. Williams, and W. F. Manley
The Cryosphere, 9, 505–523,Short summary
An overall negative glacier surface area change of 0.5±0.2% yr-1 was observed for the eastern Himalaya since 1962 based on remote sensing data. There were higher rates of area loss for clean glaciers (-34%, or -0.7% yr-1) compared to debris-covered glaciers (-14.3% or -0.3 yr-1) on a glacier-by-glacier basis. Patterns of area change are heterogenous and depend on topographic and climatic factors, glacier altitude (maximum, median, altitudinal range), glacier size, slope and aspect.
F. Brun, M. Dumont, P. Wagnon, E. Berthier, M. F. Azam, J. M. Shea, P. Sirguey, A. Rabatel, and Al. Ramanathan
The Cryosphere, 9, 341–355,
T. Dunse, T. Schellenberger, J. O. Hagen, A. Kääb, T. V. Schuler, and C. H. Reijmer
The Cryosphere, 9, 197–215,
J. C. Ryan, A. L. Hubbard, J. E. Box, J. Todd, P. Christoffersen, J. R. Carr, T. O. Holt, and N. Snooke
The Cryosphere, 9, 1–11,Short summary
An unmanned aerial vehicle (UAV) equipped with a commercial digital camera enabled us to obtain high-resolution digital images of the calving front of Store glacier, Greenland. The three sorties flown enabled key glaciological parameters to be quantified in sufficient detail to reveal that the terminus of Store glacier is a complex system with large variations in crevasse patterns surface velocities, calving processes, surface elevations and front positions at a daily and seasonal timescale.
M. Schaefer, H. Machguth, M. Falvey, G. Casassa, and E. Rignot
The Cryosphere, 9, 25–35,Short summary
We use a meteorological-glaciological multi-model approach to quantify, for the first time, melt and accumulation of snow on the Southern Patagonia Icefield (SPI). We were able to reproduce the high measured accumulation of snow of up to 15.4 m water equivalent per year as well as the high measured ablation of up to 11 m water equivalent per year. Mass losses of the SPI due to calving of icebergs strongly increased from 1975-2000 to 2000-2011 and were higher than losses due to surface melt.
J. Todd and P. Christoffersen
The Cryosphere, 8, 2353–2365,Short summary
Many iceberg-calving glaciers in Greenland have recently been observed to accelerate and retreat, prompting fears about their future stability in the face of climate change. We present results from a flow modelling study of Store Glacier, West Greenland, which suggest that glacier geometry may play an important role in determining calving glacier stability. Store Glacier flows into a narrow, shallow fjord and our model suggests this may make it insensitive to future ocean warming.
H. Frey, H. Machguth, M. Huss, C. Huggel, S. Bajracharya, T. Bolch, A. Kulkarni, A. Linsbauer, N. Salzmann, and M. Stoffel
The Cryosphere, 8, 2313–2333,Short summary
Existing methods (area–volume relations, a slope-dependent volume estimation method, and two ice-thickness distribution models) are used to estimate the ice reserves stored in Himalayan–Karakoram glaciers. Resulting volumes range from 2955–4737km³. Results from the ice-thickness distribution models agree well with local measurements; volume estimates from area-related relations exceed the estimates from the other approaches. Evidence on the effect of the selected method on results is provided.
Cuffey, K. M. and Paterson, W. S. B.: The Physics of Glaciers (Fourth Edition). Burlington MA: Butterworth-Heineman, 693 pp., 2010.
Engelder, T: Stress regimes in the lithosphere. Princeton NJ: Princeton University Press, 457 pp., 1993.
Hughes, T.: The Jakobshavn Effect, Geophys. Res. Lett., 13, 46–48, 1986.
Hughes, T.: On the pulling power of ice streams, J. Glaciol., 38, 125–151, 1992.
Hughes, T. J.: Ice Sheets, New York NY, Oxford University Press, 343 pp., 1998
Hughes, T. J.: Geometrical force balance in glaciology, J. Geophys. Res., 108, 2526, https://doi.org/10.1029/2003JB002557, 2003.
Hughes, T. J.: Holistic ice sheet modeling: a first-order approach, University of Maine, 188 pp., 2008.
Hughes, T.: Variations of ice bed coupling beneath and beyond ice streams: The force balance, J. Geophys. Res., 114, B01410, https://doi.org/10.1029/2008JB005714, 2009a.
Hughes, T.: Correction to "Variations of ice bed coupling beneath and beyond ice streams: The force balance", J. Geophys. Res., 114, B04499, https://doi.org/10.1029/2009JB006426, 2009b.
Hughes, T.: Holistic Ice Sheet Modeling. A First-Order Approach, New York, Nova Publishers, 261 pp., 2012.
Hughes, T., Sargent, A., and Fastook, J.: Ice-bed coupling beneath and beyond ice streams: Byrd Glacier, Antarctica, J. Geophys. Res., 116, F03005, https://doi.org/10.1029/2010JF001896, 2011.
Hughes, T., Sargent, A., Fastook, J., Purdon, K., Li, J., Yan, J.-B., and Gogineni, S.: Sheet, stream, and shelf flow as progressive ice-bed uncoupling: Byrd Glacier, Antarctica and Jakobshavn Isbrae, Greenland, The Cryosphere, 10, 193–225, https://doi.org/10.5194/tc-10-193-2016, 2016.
Pfeffer, W. T.: A simple mechanism for irreversible tidewater glacier retreat, J. Geophys. Res., 112, F03S25, https://doi.org/10.1029/2006JF000590, 2007.
Reusch, D. and Hughes, T.: Surface “waves” on Byrd Glacier, Antarctica, Antarct. Sci., 15, 547–555, 2003.
Turcotte, D. L. and Schubert, G.: Geodynamics (Second Edition), Cambridge, Cambridge University Press, 456 pp., 2002.
Van der Veen, C. J.: Fundamentals of Glacier Dynamics, Boca Raton, Taylor & Francis, 389 pp., 2013.
Van der Veen, C. J. and Whillans, I. M.: Force budget: 1. Theory and numerical methods, J. Glaciol., 35, 53–60, 1989.
Van der Veen, C. J. and Payne, A. J.: Modelling land-ice dynamics. In: Mass balance of the cryosphere: observations and modelling of contemporary and future changes, edited by: Bamber, J. L. and Payne, A. J., Cambridge, Cambridge University Press, 169–225, 2004.
Van der Veen, C. J., Stearns, L. A., Johnson, J., and Csatho, B.: Flow dynamics of Byrd Glacier, East Antarctica, J. Glaciol., 60, 1053–1064, 2014.
Weertman, J.: Deformation of floating ice shelves, J. Glaciol., 3, 38–42, 1957.
Whillans, I. M.: Force budget of ice sheets. In: Dynamics of the West Antarctic Ice Sheets, edited by: Van der Veen, C. J. and Oerlemans, J., Dordrecht, Reidel, 17–36, 1987.
Whillans, I. M., Chen, Y. H., Van der Veen, C. J., and Hughes, T. J.: Force budget: III. Application to three-dimensional flow of Byrd Glacier, Antarctica, J. Glaciol., 119, 68–80, 1989.
This paper evaluates the geometric force balance, with application to Byrd Glacier, Antarctica. It is concluded that this approach does not yield physically reasonable results.
This paper evaluates the geometric force balance, with application to Byrd Glacier, Antarctica....