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Aldegondabreen glacier change since 1910 from structure-from-motion photogrammetry of archived terrestrial and aerial photographs: utility of a historic archive to obtain century-scale Svalbard glacier mass losses J. Glaciol. (IF 3.024) Pub Date : 2020-11-10 Erik Schytt Holmlund
Photogrammetric reconstructions of the Aldegondabreen glacier on Svalbard from 17 archival terrestrial oblique photographs taken in 1910 and 1911 reveal a past volume of 1373.7 ± 78.2 · 106 m3; almost five times greater than its volume in 2016. Comparisons to elevation data obtained from aerial and satellite imagery indicate a relatively unchanging volume loss rate of − 10.1 ± 1.6 · 106 m3 a−1 over
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Spatio-temporal variability of surface mass balance in the accumulation zone of the Mer de Glace, French Alps, from multitemporal terrestrial LiDAR measurements J. Glaciol. (IF 3.024) Pub Date : 2020-12-02 Marion Réveillet; Christian Vincent; Delphine Six; Antoine Rabatel; Olivier Sanchez; Luc Piard; Olivier Laarman
Spatio-temporal variability of the winter surface mass balance is a major uncertainty in the modelling of annual surface mass balance. Moreover, its measurement at high spatio-temporal resolution (sub-200 m) is very useful to force, calibrate or validate models. This study presents the results of year-round field campaigns to study the evolution of the surface mass balance in a ~2 km2 portion of the
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Twenty-first century response of Petermann Glacier, northwest Greenland to ice shelf loss J. Glaciol. (IF 3.024) Pub Date : 2020-12-02 Emily A. Hill; G. Hilmar Gudmundsson; J. Rachel Carr; Chris R. Stokes; Helen M. King
Ice shelves restrain flow from the Greenland and Antarctic ice sheets. Climate-ocean warming could force thinning or collapse of floating ice shelves and subsequently accelerate flow, increase ice discharge and raise global mean sea levels. Petermann Glacier (PG), northwest Greenland, recently lost large sections of its ice shelf, but its response to total ice shelf loss in the future remains uncertain
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Glacier albedo reduction and drought effects in the extratropical Andes, 1986–2020 J. Glaciol. (IF 3.024) Pub Date : 2020-12-17 Thomas E. Shaw; Genesis Ulloa; David Farías-Barahona; Rodrigo Fernandez; Jose M. Lattus; James McPhee
Surface albedo typically dominates the mass balance of mountain glaciers, though long-term trends and patterns of glacier albedo are seldom explored. We calculated broadband shortwave albedo for glaciers in the central Chilean Andes (33–34°S) using end-of-summer Landsat scenes between 1986 and 2020. We found a high inter-annual variability of glacier-wide albedo that is largely a function of the glacier
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Seasonally stable temperature gradients through supraglacial debris in the Everest region of Nepal, Central Himalaya J. Glaciol. (IF 3.024) Pub Date : 2020-12-03 Ann V. Rowan; Lindsey I. Nicholson; Duncan J. Quincey; Morgan J. Gibson; Tristram D.L. Irvine-Fynn; C. Scott Watson; Patrick Wagnon; David R. Rounce; Sarah S. Thompson; Philip R. Porter; Neil F. Glasser
Rock debris covers ~30% of glacier ablation areas in the Central Himalaya and modifies the impact of atmospheric conditions on mass balance. The thermal properties of supraglacial debris are diurnally variable but remain poorly constrained for monsoon-influenced glaciers over the timescale of the ablation season. We measured vertical debris profile temperatures at 12 sites on four glaciers in the Everest
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Cyclic strengthening of lake ice J. Glaciol. (IF 3.024) Pub Date : 2020-11-16 Andrii Murdza; Aleksey Marchenko; Erland M. Schulson; Carl E. Renshaw
Further to systematic experiments on the flexural strength of laboratory-grown, fresh water ice loaded cyclically, this paper describes results from new experiments of the same kind on lake ice harvested in Svalbard. The experiments were conducted at −12 °C, 0.1 Hz frequency and outer-fiber stress in the range from ~ 0.1 to ~ 0.7 MPa. The results suggest that the flexural strength increases linearly
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Spatiotemporal variability of surface velocities of monsoon temperate glaciers in the Kangri Karpo Mountains, southeastern Tibetan Plateau J. Glaciol. (IF 3.024) Pub Date : 2020-12-04 Kunpeng Wu; Shiyin Liu; Junli Xu; Yu Zhu; Qiao Liu; Zongli Jiang; Junfeng Wei
Influenced by the Indian monsoon, the Kangri Karpo Mountains (KKM) of the southeastern Tibetan Plateau is the most humid part of the plateau, and one of the most important regions with numerous monsoon temperate glaciers. Glacier mass balance estimates have been strongly negative in the KKM over recent decades, but the spatiotemporal characteristics of surface velocity are poorly understood. Using
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Constraining subglacial processes from surface velocity observations using surrogate-based Bayesian inference J. Glaciol. (IF 3.024) Pub Date : 2021-01-18 Douglas Brinkerhoff; Andy Aschwanden; Mark Fahnestock
Basal motion is the primary mechanism for ice flux in Greenland, yet a widely applicable model for predicting it remains elusive. This is due to the difficulty in both observing small-scale bed properties and predicting a time-varying water pressure on which basal motion putatively depends. We take a Bayesian approach to these problems by coupling models of ice dynamics and subglacial hydrology and
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Evaluation of sea-ice thickness reanalysis data from the coupled ocean-sea-ice data assimilation system TOPAZ4 J. Glaciol. (IF 3.024) Pub Date : 2021-01-13 Yongwu Xiu; Chao Min; Jiping Xie; Longjiang Mu; Bo Han; Qinghua Yang
With the assimilation of satellite-based sea-ice thickness (SIT) data, the new SIT reanalysis from the Towards an Operational Prediction system for the North Atlantic European coastal Zones (TOPAZ4) was released from 2014 to 2018. Apart from assimilating sea-ice concentration and oceanic variables, TOPAZ4 further assimilates CS2SMOS SIT. In this study, the 5-year reanalysis is compared with CS2SMOS
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An imbalancing act: the delayed dynamic response of the Kaskawulsh Glacier to sustained mass loss J. Glaciol. (IF 3.024) Pub Date : 2020-12-29 Erik M. Young; Gwenn E. Flowers; Etienne Berthier; Rebecca Latto
The Kaskawulsh Glacier is an iconic outlet draining the icefields of the St. Elias Mountains in Yukon, Canada. We determine and attempt to interpret its catchment-wide mass budget since 2007. Using SPOT5/6/7 data we estimate a 2007–18 geodetic balance of −0.46 ± 0.17 m w.e. a−1. We then compute balance fluxes and observed ice fluxes at nine flux gates to examine the discrepancy between the climatic
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Effect of horizontal divergence on estimates of firn-air content J. Glaciol. (IF 3.024) Pub Date : 2020-12-29 Annika N. Horlings; Knut Christianson; Nicholas Holschuh; C. Max Stevens; Edwin D. Waddington
Ice-sheet mass-balance estimates derived from repeat satellite-altimetry observations require accurate calculation of spatiotemporal variability in firn-air content (FAC). However, firn-compaction models remain a large source of uncertainty within mass-balance estimates. In this study, we investigate one process that is neglected in FAC estimates derived from firn-compaction models: enhanced layer
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Influence of glacier runoff and near-terminus subglacial hydrology on frontal ablation at a large Greenlandic tidewater glacier J. Glaciol. (IF 3.024) Pub Date : 2020-12-29 Charlie Bunce; Peter Nienow; Andrew Sole; Tom Cowton; Benjamin Davison
Frontal ablation from tidewater glaciers is a major component of the total mass loss from the Greenland ice sheet. It remains unclear, however, how changes in atmospheric and oceanic temperatures translate into changes in frontal ablation, in part due to sparse observations at sufficiently high spatial and temporal resolution. We present high-frequency time-lapse imagery (photos every 30 min) of iceberg
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Application of an improved surface energy balance model to two large valley glaciers in the St. Elias Mountains, Yukon J. Glaciol. (IF 3.024) Pub Date : 2020-12-23 Tim Hill; Christine F. Dow; Eleanor A. Bash; Luke Copland
Glacier surficial melt rates are commonly modelled using surface energy balance (SEB) models, with outputs applied to extend point-based mass-balance measurements to regional scales, assess water resource availability, examine supraglacial hydrology and to investigate the relationship between surface melt and ice dynamics. We present an improved SEB model that addresses the primary limitations of existing
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Comparison of historical and recent accumulation rates on Abramov Glacier, Pamir Alay J. Glaciol. (IF 3.024) Pub Date : 2020-12-23 Marlene Kronenberg; Horst Machguth; Anja Eichler; Margit Schwikowski; Martin Hoelzle
Glaciers located in western High Mountain Asia (HMA) have shown mass gain or limited mass losses compared to other mountain regions since ~2000. Increases in accumulation may be responsible. Although no contemporary measurements exist to explore this hypothesis, extensive historic measurements including firn density, stratigraphy and accumulation rates at ~4400 m a.s.l. on Abramov Glacier, Pamir Alay
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Sediment redistribution beneath the terminus of an advancing glacier, Taku Glacier (T'aakú Kwáan Sít'i), Alaska J. Glaciol. (IF 3.024) Pub Date : 2020-12-23 Jenna M. Zechmann; Martin Truffer; Roman J. Motyka; Jason M. Amundson; Chris F. Larsen
The recently-advancing Taku Glacier is excavating subglacial sediments at high rates over multi-decadal timescales. However, sediment redistribution over shorter timescales remains unquantified. We use a variety of methods to study subglacial and proglacial sediment redistribution on decadal, seasonal, and daily timescales to gain insight into sub- and proglacial landscape formation. Both excavation
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Measuring and inferring the ice thickness distribution of four glaciers in the Tien Shan, Kyrgyzstan J. Glaciol. (IF 3.024) Pub Date : 2020-12-22 Lander Van Tricht; Philippe Huybrechts; Jonas Van Breedam; Johannes J. Fürst; Oleg Rybak; Rysbek Satylkanov; Bakyt Ermenbaiev; Victor Popovnin; Robbe Neyns; Chloë Marie Paice; Philipp Malz
Glaciers in the Tien Shan mountains contribute considerably to the fresh water used for irrigation, households and energy supply in the dry lowland areas of Kyrgyzstan and its neighbouring countries. To date, reconstructions of the current ice volume and ice thickness distribution remain scarce, and accurate data are largely lacking at the local scale. Here, we present a detailed ice thickness distribution
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Reconstruction of historical surface mass balance, 1984–2017 from GreenTrACS multi-offset ground-penetrating radar J. Glaciol. (IF 3.024) Pub Date : 2020-12-14 Tate G. Meehan; H. P. Marshall; John H. Bradford; Robert L. Hawley; Thomas B. Overly; Gabriel Lewis; Karina Graeter; Erich Osterberg; Forrest McCarthy
We present continuous estimates of snow and firn density, layer depth and accumulation from a multi-channel, multi-offset, ground-penetrating radar traverse. Our method uses the electromagnetic velocity, estimated from waveform travel-times measured at common-midpoints between sources and receivers. Previously, common-midpoint radar experiments on ice sheets have been limited to point observations
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Drygalski Ice Tongue stability influenced by rift formation and ice morphology J. Glaciol. (IF 3.024) Pub Date : 2020-12-07 Christine Indrigo; Christine F. Dow; Jamin S. Greenbaum; Mathieu Morlighem
The Drygalski Ice Tongue in East Antarctica stretches 90 km into the Ross Sea and influences the local ocean circulation, and persistence of the Terra Nova Bay Polynya. We examine the controls on the size of this floating ice body by comparing the propagation of six large fractures on the ice tongue's northern side using 21 years of Landsat imagery with hydrostatic ice thickness maps and strain rate
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Characterization of snowfall estimated by in situ and ground-based remote-sensing observations at Terra Nova Bay, Victoria Land, Antarctica J. Glaciol. (IF 3.024) Pub Date : 2020-10-01 Claudio Scarchilli; Virginia Ciardini; Paolo Grigioni; Antonio Iaccarino; Lorenzo De Silvestri; Marco Proposito; Stefano Dolci; Giuseppe Camporeale; Riccardo Schioppo; Adriano Antonelli; Luca Baldini; Nicoletta Roberto; Stefania Argentini; Alessandro Bracci; Massimo Frezzotti
Knowledge of the precipitation contribution to the Antarctic surface mass balance is essential for defining the ice-sheet contribution to sea-level rise. Observations of precipitation are sparse over Antarctica, due to harsh environmental conditions. Precipitation during the summer months (November–December–January) on four expeditions, 2015–16, 2016–17, 2017–18 and 2018–19, in the Terra Nova Bay area
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Bias-corrected estimates of glacier thickness in the Columbia River Basin, Canada J. Glaciol. (IF 3.024) Pub Date : 2020-09-24 Ben M. Pelto; Fabien Maussion; Brian Menounos; Valentina Radić; Maurice Zeuner
Several global datasets of glacier thickness exist, but the number of observations from western Canada are sparse and spatially biased. To supplement these limited observations, we measured ice thickness with ice penetrating radar on five glaciers in the Columbia Mountains, Canada. Our radar surveys, when combined with previous surveys for two glaciers in the Rocky Mountains, total 182 km of transects
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Characteristics of ice rises and ice rumples in Dronning Maud Land and Enderby Land, Antarctica J. Glaciol. (IF 3.024) Pub Date : 2020-10-01 Vikram Goel; Kenichi Matsuoka; Cesar Deschamps Berger; Ian Lee; Jørgen Dall; René Forsberg
Ice rises and rumples, locally grounded features adjacent to ice shelves, are relatively small yet play significant roles in Antarctic ice dynamics. Their roles generally depend upon their location within the ice shelf and the stage of the ice-sheet retreat or advance. Large, long-stable ice rises can be excellent sites for deep ice coring and paleoclimate study of the Antarctic coast and the Southern
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A new approach to inferring basal drag and ice rheology in ice streams, with applications to West Antarctic Ice Streams J. Glaciol. (IF 3.024) Pub Date : 2020-11-06 Meghana Ranganathan; Brent Minchew; Colin R. Meyer; G. Hilmar Gudmundsson
Drag at the bed and along the lateral margins are the primary forces resisting flow in outlet glaciers. Simultaneously inferring these parameters is challenging since basal drag and ice viscosity are coupled in the momentum balance, which governs ice flow. We test the ability of adjoint-based inverse methods to infer the slipperiness coefficient in a power-law sliding law and the flow-rate parameter
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Spectral albedo of coastal landfast sea ice in Prydz Bay, Antarctica J. Glaciol. (IF 3.024) Pub Date : 2020-11-05 Guanghua Hao; Roberta Pirazzini; Qinghua Yang; Zhongxiang Tian; Changwei Liu
The surface spectral albedo was measured over coastal landfast sea ice in Prydz Bay (off Zhongshan Station), East Antarctica from 5 October to 26 November of 2016. The mean albedo decreased from late-spring to early-summer, mainly responding to the change in surface conditions from dry (phase I) to wet (phase II). The evolution of the albedo was strongly influenced by the surface conditions, with alternation
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Reanalysing the 2007–19 glaciological mass-balance series of Mera Glacier, Nepal, Central Himalaya, using geodetic mass balance J. Glaciol. (IF 3.024) Pub Date : 2020-11-04 Patrick Wagnon; Fanny Brun; Arbindra Khadka; Etienne Berthier; Dibas Shrestha; Christian Vincent; Yves Arnaud; Delphine Six; Amaury Dehecq; Martin Ménégoz; Vincent Jomelli
The 2007–19 glaciological mass-balance series of Mera Glacier in the Everest Region, East Nepal, is reanalysed using the geodetic mass balance assessed by differencing two DEMs obtained from Pléiades stereo-images acquired in November 2012 and in October 2018. The glaciological glacier-wide annual mass balance of Mera Glacier has to be systematically decreased by 0.11 m w.e. a−1 to match the geodetic
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Study of freeze-thaw cycle and key radiation transfer parameters in a Tibetan Plateau lake using LAKE2.0 model and field observations J. Glaciol. (IF 3.024) Pub Date : 2020-11-04 Zhaoguo Li; Shihua Lyu; Lijuan Wen; Lin Zhao; Yinhuan Ao; Xianhong Meng
The Tibetan Plateau (TP) lakes are sensitive to climate change due to its seasonal ice cover, but few studies have paid attention to the freeze-thaw process of TP lakes and its key control parameters. By combining 216 simulation experiments using the LAKE2.0 model with the observations, we evaluated the effects of ice and snow albedo, ice (Kdi) and water (Kdw) extinction coefficients on the lake ice
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Teleseismic earthquake wavefields observed on the Ross Ice Shelf J. Glaciol. (IF 3.024) Pub Date : 2020-10-14 Michael G. Baker; Richard C. Aster; Douglas A. Wiens; Andrew Nyblade; Peter D. Bromirski; Peter Gerstoft; Ralph A. Stephen
Observations of teleseismic earthquakes using broadband seismometers on the Ross Ice Shelf (RIS) must contend with environmental and structural processes that do not exist for land-sited seismometers. Important considerations are: (1) a broadband, multi-mode ambient wavefield excited by ocean gravity wave interactions with the ice shelf; (2) body wave reverberations produced by seismic impedance contrasts
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Deep multi-scale learning for automatic tracking of internal layers of ice in radar data J. Glaciol. (IF 3.024) Pub Date : 2020-10-12 Maryam Rahnemoonfar; Masoud Yari; John Paden; Lora Koenig; Oluwanisola Ibikunle
In this study, our goal is to track internal ice layers on the Snow Radar data collected by NASA Operation IceBridge. We examine the application of deep learning methods on radar data gathered from polar regions. Artificial intelligence techniques have displayed impressive success in many practical fields. Deep neural networks owe their success to the availability of massive labeled data. However,
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Stochastic modeling of subglacial topography exposes uncertainty in water routing at Jakobshavn Glacier J. Glaciol. (IF 3.024) Pub Date : 2020-10-12 Emma J. MacKie; Dustin M. Schroeder; Chen Zuo; Zhen Yin; Jef Caers
Subglacial topography is an important feature in numerous ice-sheet analyses and can drive the routing of water at the bed. Bed topography is primarily measured with ice-penetrating radar. Significant gaps, however, remain in data coverage that require interpolation. Topographic interpolations are typically made with kriging, as well as with mass conservation, where ice flow dynamics are used to constrain
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A dual-tube sampling technique for snowpack studies J. Glaciol. (IF 3.024) Pub Date : 2020-10-09 Remi Dallmayr; Johannes Freitag; Maria Hörhold; Thomas Laepple; Johannes Lemburg; Damiano Della-Lunga; Frank Wilhelms
The validity of any glaciological paleo proxy used to interpret climate records is based on the level of understanding of their transfer from the atmosphere into the ice sheet and their recording in the snowpack. Large spatial noise in snow properties is observed, as the wind constantly redistributes the deposited snow at the surface routed by the local topography. To increase the signal-to-noise ratio
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Snow wetness retrieved from close-range L-band radiometry in the western Greenland ablation zone J. Glaciol. (IF 3.024) Pub Date : 2020-10-07 Reza Naderpour; Derek Houtz; Mike Schwank
Close-range (CR) L-band radiometry and quasi-simultaneous in situ snow characterizations were conducted in May 2019 at the Swiss Camp research site in the ablation zone of the western Greenland ice sheet. Snow liquid-water and its melt/refreeze are retrieved from microwave antenna temperatures measured with the ground-based L-band radiometer ELBARA-III. The emission model (EM) used in the retrieval
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Updated inventory of glacier ice in New Zealand based on 2016 satellite imagery J. Glaciol. (IF 3.024) Pub Date : 2020-10-07 Sabine Baumann; Brian Anderson; Trevor Chinn; Andrew Mackintosh; Catherine Collier; Andrew M. Lorrey; Wolfgang Rack; Heather Purdie; Shaun Eaves
The only complete inventory of New Zealand glaciers was based on aerial photography starting in 1978. While there have been partial updates using 2002 and 2009 satellite data, most glaciers are still represented by the 1978 outlines in contemporary global glacier databases. The objective of this project is to establish an updated glacier inventory for New Zealand. We have used Landsat 8 OLI satellite
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Future projection of cryospheric and hydrologic regimes in Koshi River basin, Central Himalaya, using coupled glacier dynamics and glacio-hydrological models J. Glaciol. (IF 3.024) Pub Date : 2020-08-26 Mira Khadka; Rijan Bhakta Kayastha; Rakesh Kayastha
Climate-induced cryospheric changes can have a significant impact on the downstream water availability. In this study, the Open Global Glacier Model (OGGM) and the Glacio-hydrological Degree-day Model (GDM) are integrated to project the response of cryospheric and hydrological systems to climate change until 2100. The study area comprises six sub-basins of glacierized Koshi River basin covering Nepalese
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A near 90-year record of the evolution of El Morado Glacier and its proglacial lake, Central Chilean Andes J. Glaciol. (IF 3.024) Pub Date : 2020-08-18 David Farías-Barahona; Ryan Wilson; Claudio Bravo; Sebastián Vivero; Alexis Caro; Thomas E. Shaw; Gino Casassa; Álvaro Ayala; Alonso Mejías; Stephan Harrison; Neil F. Glasser; James McPhee; Olaf Wündrich; Matthias H. Braun
Using an ensemble of close- and long-range remote sensing, lake bathymetry and regional meteorological data, we present a detailed assessment of the geometric changes of El Morado Glacier in the Central Andes of Chile and its adjacent proglacial lake between 1932 and 2019. Overall, the results revealed a period of marked glacier down wasting, with a mean geodetic glacier mass balance of −0.39 ± 0.15
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Annual cycle in flow of Ross Ice Shelf, Antarctica: contribution of variable basal melting J. Glaciol. (IF 3.024) Pub Date : 2020-08-03 Emilie Klein; Cyrille Mosbeux; Peter D. Bromirski; Laurie Padman; Yehuda Bock; Scott R. Springer; Helen A. Fricker
Ice shelves play a critical role in modulating dynamic loss of ice from the grounded portion of the Antarctic Ice Sheet and its contribution to sea-level rise. Measurements of ice-shelf motion provide insights into processes modifying buttressing. Here we investigate the effect of seasonal variability of basal melting on ice flow of Ross Ice Shelf. Velocities were measured from November 2015 to December
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Volume-area scaling for debris-covered glaciers J. Glaciol. (IF 3.024) Pub Date : 2020-08-18 Argha Banerjee
A volume-area scaling relation is commonly used to estimate glacier volume or its future changes on a global scale. The presence of an insulating supraglacial debris cover alters the mass-balance profile of a glacier, potentially modifying the scaling relation. Here, the nature of scaling relations for extensively debris-covered glaciers is investigated. Theoretical arguments suggest that the volume-area
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Interannual modulation of seasonal glacial velocity variations in the Eastern Karakoram detected by ALOS-1/2 data – ERRATUM J. Glaciol. (IF 3.024) Pub Date : 2020-07-28 Muhammad Usman; Masato Furuya
Unlike in most other regions, Karakoram glaciers are either stable or advancing, a phenomenon known as the Karakoram anomaly. Despite studies of glacier surges and the derivation of surface velocity maps, the spatiotemporal variability of glacier dynamics still remains poorly understood, particularly in the Eastern Karakoram Range. We use Advanced Land Observing Satellite/the Phased Array type L-band
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A doubling of glacier mass loss in the Karlik Range, easternmost Tien Shan, between the periods 1972–2000 and 2000–2015 J. Glaciol. (IF 3.024) Pub Date : 2020-09-23 Zhujun Wan; Yetang Wang; Shugui Hou; Baojuan Huai; Qi Liu
Despite a number of studies reporting glacier extent changes and their response to climate change over the eastern Tien Shan, glacier mass-balance changes over multiple decades are still not well reconstructed. Here, glacier mass budgets on the Karlik Range, easternmost Tien Shan during the time spans of 1972–2000 and 2000–2015 are quantified using digital elevation models reconstructed from topographic
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Antarctic ice sheet response to sudden and sustained ice-shelf collapse (ABUMIP) J. Glaciol. (IF 3.024) Pub Date : 2020-09-14 Sainan Sun; Frank Pattyn; Erika G. Simon; Torsten Albrecht; Stephen Cornford; Reinhard Calov; Christophe Dumas; Fabien Gillet-Chaulet; Heiko Goelzer; Nicholas R. Golledge; Ralf Greve; Matthew J. Hoffman; Angelika Humbert; Elise Kazmierczak; Thomas Kleiner; Gunter R. Leguy; William H. Lipscomb; Daniel Martin; Mathieu Morlighem; Sophie Nowicki; David Pollard; Stephen Price; Aurélien Quiquet; Hélène Seroussi;
Antarctica's ice shelves modulate the grounded ice flow, and weakening of ice shelves due to climate forcing will decrease their ‘buttressing’ effect, causing a response in the grounded ice. While the processes governing ice-shelf weakening are complex, uncertainties in the response of the grounded ice sheet are also difficult to assess. The Antarctic BUttressing Model Intercomparison Project (ABUMIP)
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On the disequilibrium response and climate change vulnerability of the mass-balance glaciers in the Alps J. Glaciol. (IF 3.024) Pub Date : 2020-09-09 Luca Carturan; Philipp Rastner; Frank Paul
Glaciers in the Alps and several other regions in the world have experienced strong negative mass balances over the past few decades. Some of them are disappearing, undergoing exceptionally negative mass balances that impact the mean regional value, and require replacement. In this study, we analyse the geomorphometric characteristics of 46 mass-balance glaciers in the Alps and the long-term mass-balance
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Evaluating the transferability of empirical models of debris-covered glacier melt J. Glaciol. (IF 3.024) Pub Date : 2020-09-08 A. Winter-Billington; R. D. Moore; R. Dadic
Supraglacial debris is significant in many regions and complicates modeling of glacier melt, which is required for predicting glacier change and its influences on hydrology and sea-level rise. Temperature-index models are a popular alternative to energy-balance models when forcing data are limited, but their transferability among glaciers and inherent uncertainty have not been documented in application
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Spatial distribution and characteristics of Andean ice masses in Argentina: results from the first National Glacier Inventory J. Glaciol. (IF 3.024) Pub Date : 2020-09-07 Laura Zalazar; Lidia Ferri; Mariano Castro; Hernán Gargantini; Melisa Gimenez; Pierre Pitte; Lucas Ruiz; Mariano Masiokas; Gustavo Costa; Ricardo Villalba
Glaciers and the periglacial environment in Argentina have been protected by the Law since 2010. This legislation required the development of the first National Glacier Inventory (NGI), which was officially presented in May 2018 and based on satellite images spanning between 2004 and 2016. Here, we present the methods and results of the NGI, summarize the glaciers’ morphological and spatial characteristics
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The age of surface-exposed ice along the northern margin of the Greenland Ice Sheet J. Glaciol. (IF 3.024) Pub Date : 2020-08-26 Joseph A. MacGregor; Mark A. Fahnestock; William T. Colgan; Nicolaj K. Larsen; Kristian K. Kjeldsen; Jeffrey M. Welker
Each summer, surface melting of the margin of the Greenland Ice Sheet exposes a distinctive visible stratigraphy that is related to past variability in subaerial dust deposition across the accumulation zone and subsequent ice flow toward the margin. Here we map this surface stratigraphy along the northern margin of the ice sheet using mosaicked Sentinel-2 multispectral satellite imagery from the end
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Chronological characteristics for snow accumulation on Styx Glacier in northern Victoria Land, Antarctica J. Glaciol. (IF 3.024) Pub Date : 2020-08-26 Yalalt Nyamgerel; Yeongcheol Han; Songyi Kim; Sang-Bum Hong; Jeonghoon Lee; Soon Do Hur
Under the potential to reconstruct the past climatic and atmospheric conditions from a deep ice core in the coastal Antarctic site (Styx Glacier), an 8.84 m long firn core (73°50.975′ S, 163°41.640′ E; 1623 m a.s.l.) was initially studied to propose a reliable age scale for the local estimation of snow accumulation rate. The seasonal variations of δ18O, methanesulfonic acid (MSA) and non-sea-salt sulfate
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Tensile strength of glacial ice deduced from observations of the 2015 eastern Skaftá cauldron collapse, Vatnajökull ice cap, Iceland J. Glaciol. (IF 3.024) Pub Date : 2020-08-26 Lizz Ultee; Colin Meyer; Brent Minchew
The representation of iceberg calving in numerical models is a key source of uncertainty in century-scale sea-level rise projections. Parameters central to model representations of calving, including the tensile strength of glacier ice, remain poorly constrained. Grain-size and sample-size dependence make it difficult to reconcile laboratory and in situ estimates of ice tensile strength. Further, assumptions
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Arctic Ice Ocean Prediction System: evaluating sea-ice forecasts during Xuelong's first trans-Arctic Passage in summer 2017 – CORRIGENDUM J. Glaciol. (IF 3.024) Pub Date : 2020-08-24 Longjiang Mu; Xi Liang; Qinghua Yang; Jiping Liu; Fei Zheng
In an effort to improve the reliability of Arctic sea-ice predictions, an ensemble-based Arctic Ice Ocean Prediction System (ArcIOPS) has been developed to meet operational demands. The system is based on a regional Arctic configuration of the Massachusetts Institute of Technology general circulation model. A localized error subspace transform ensemble Kalman filter is used to assimilate the weekly
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239,240Pu and 236U records of an ice core from the eastern Tien Shan (Central Asia) – CORRIGENDUM J. Glaciol. (IF 3.024) Pub Date : 2020-08-24 Chaomin Wang; Shugui Hou; Hongxi Pang; Yaping Liu; Heinz Walter Gäggeler; Marcus Christl; Hans-Arno Synal
Radioisotopes (239Pu, 240Pu, 236U) formed during atmospheric nuclear weapons testing (NWT) can be used for dating and therefore be applied as markers of the beginning of the Anthropocene Epoch. Moreover, 240Pu/239Pu ratios enable source identification (general fallout, local emission sources). Ice core segments from a 57.6 m ice core to bedrock from eastern Tien Shan, China were selected for 239,240Pu
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In situ effective snow grain size mapping using a compact hyperspectral imager J. Glaciol. (IF 3.024) Pub Date : 2020-08-18 Christopher Donahue; S. McKenzie Skiles; Kevin Hammonds
Effective snow grain radius (re) is mapped at high resolution using near-infrared hyperspectral imaging (NIR-HSI). The NIR-HSI method can be used to quantify re spatial variability, change in re due to metamorphism, and visualize water percolation in the snowpack. Results are presented for three different laboratory-prepared snow samples (homogeneous, ice lens, fine grains over coarse grains), the
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Slope estimation influences on ice thickness inversion models: a case study for Monte Tronador glaciers, North Patagonian Andes J. Glaciol. (IF 3.024) Pub Date : 2020-08-18 Valentina Zorzut; Lucas Ruiz; Andres Rivera; Pierre Pitte; Ricardo Villalba; Dorota Medrzycka
Glacier ice thickness is crucial to quantifying water resources in mountain regions, and is an essential input for ice-flow models. Using a surface velocity inversion method, we combine ice thickness measurements with detailed surface elevation and velocity data, and derive ice thickness and volume estimates for the Monte Tronador glaciers, North Patagonian Andes. We test the dependence of the inversion
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Ensemble matching of repeat satellite images applied to measure fast-changing ice flow, verified with mountain climber trajectories on Khumbu icefall, Mount Everest J. Glaciol. (IF 3.024) Pub Date : 2020-08-11 Bas Altena; Andreas Kääb
Velocities within an icefall are typically the fastest within a glacier system and experience complex flow. The combination of convergent and fast flow, and steep slope generate a quickly changing and intensely fractured surface. This complicates velocity extraction from repeat satellite images, especially when common pattern matching procedures are used. In this study, we exploit the high temporal
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A scale-dependent model to represent changing aerodynamic roughness of ablating glacier ice based on repeat topographic surveys J. Glaciol. (IF 3.024) Pub Date : 2020-08-04 Thomas Smith; Mark W. Smith; Joshua R. Chambers; Rudolf Sailer; Lindsey Nicholson; Jordan Mertes; Duncan J. Quincey; Jonathan L. Carrivick; Ivana Stiperski
Turbulent fluxes make a substantial and growing contribution to the energy balance of ice surfaces globally, but are poorly constrained owing to challenges in estimating the aerodynamic roughness length (z0). Here, we used structure from motion (SfM) photogrammetry and terrestrial laser scanning (TLS) surveys to make plot-scale 2-D and 3-D microtopographic estimations of z0 and upscale these to map
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Examining geodetic glacier mass balance in the eastern Pamir transition zone J. Glaciol. (IF 3.024) Pub Date : 2020-08-03 Mingyang Lv; Duncan J. Quincey; Huadong Guo; Owen King; Guang Liu; Shiyong Yan; Xiancai Lu; Zhixing Ruan
Glaciers in the eastern Pamir have reportedly been gaining mass during recent decades, even though glaciers in most other regions in High Mountain Asia have been in recession. Questions still remain about whether the trend is strengthening or weakening, and how far the positive balances extend into the eastern Pamir. To address these gaps, we use three different digital elevation models to reconstruct
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Historical surface mass balance from a frequency-modulated continuous-wave (FMCW) radar survey from Zhongshan station to Dome A J. Glaciol. (IF 3.024) Pub Date : 2020-08-03 Jingxue Guo; Wangxiao Yang; Yinke Dou; Xueyuan Tang; Jamin S. Greenbaum; Ruofan Dou; Yao Pan; Yuzhong Zhang; Minghu Ding; Su Jiang; Guitao Shi; Xiangbin Cui; Bo Sun
Using frequency-modulated continuous wave radar data from the 32nd Chinese Antarctic Research Expedition in 2015/16, subsurface profiles were obtained along an East Antarctic inland traverse from Zhongshan station to Dome A, and four distinct regions were selected to analyze the spatiotemporal variability in historical surface mass balance (SMB). Based on depth, density, and age data from ice cores
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Modelling dynamic ice-sheet boundaries and grounding line migration using the level set method J. Glaciol. (IF 3.024) Pub Date : 2020-07-17 M. Alamgir Hossain; Sam Pimentel; John M. Stockie
Computing predictions of future sea level that include well-defined uncertainty bounds requires models that are capable of robustly simulating the evolution of ice sheets and glaciers. Ice flow behaviour is known to be sensitive to the location and geometry of dynamic ice boundaries such as the grounding line (GRL), terminus position and ice surface elevation, so that any such model should track these
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Validation of remote-sensing products of sea-ice motion: a case study in the western Arctic Ocean J. Glaciol. (IF 3.024) Pub Date : 2020-07-10 Dawei Gui; Ruibo Lei; Xiaoping Pang; Jennifer K. Hutchings; Guangyu Zuo; Mengxi Zhai
The accuracy of sea-ice motion products provided by the National Snow and Ice Data Center (NSIDC) and the Ocean and Sea Ice Satellite Application Facility (OSI-SAF) was validated with data collected by ice drifters that were deployed in the western Arctic Ocean in 2014 and 2016. Data from both NSIDC and OSI-SAF products exhibited statistically significant (p < 0.001) correlation with drifter data.
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The influence of environmental microseismicity on detection and interpretation of small-magnitude events in a polar glacier setting J. Glaciol. (IF 3.024) Pub Date : 2020-07-08 Chris G. Carr; Joshua D. Carmichael; Erin C. Pettit; Martin Truffer
Glacial environments exhibit temporally variable microseismicity. To investigate how microseismicity influences event detection, we implement two noise-adaptive digital power detectors to process seismic data from Taylor Glacier, Antarctica. We add scaled icequake waveforms to the original data stream, run detectors on the hybrid data stream to estimate reliable detection magnitudes and compare analytical
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Insights into drumlin development from ground-penetrating radar at Múlajökull, Iceland, a surge-type glacier J. Glaciol. (IF 3.024) Pub Date : 2020-07-08 Jacob B. Woodard; Lucas K. Zoet; Ívar Ö. Benediktsson; Neal R. Iverson; Andrew Finlayson
Drumlins form at the ice/bed interface through subglacial processes that are not directly observable. The internal stratigraphy of drumlins provides insight into how they developed and associated subglacial processes, but traditional stratigraphic logging techniques are limited to natural exposures and excavations. Using ground-penetrating radar, we imaged the internal stratigraphy of seven drumlins
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Maximizing friction in the erosion of glacial valleys J. Glaciol. (IF 3.024) Pub Date : 2020-07-07 Valerio Faraoni
The cross-sectional profile of a glacial valley can be obtained with a variational principle in which the friction against the valley walls and the glacier bed is extremized, subject to a Lagrangian constraint. We show that the actual valley profile maximizes the friction, thus settling an old debate.
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Variations in surface area of six ice aprons in the Mont-Blanc massif since the Little Ice Age J. Glaciol. (IF 3.024) Pub Date : 2020-07-06 Grégoire Guillet; Ludovic Ravanel
Deglaciation of high mountain rockwalls alters slope stability as rockwalls become more sensitive to modifications in environmental factors (e.g. seasonal temperature variations). In the past decades, increasing efforts focused on studying deglaciated Alpine rockwalls. Yet, currently deglaciating rockfaces remain unstudied. Here, we quantify surface area variations of massive ice bodies lying on high
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The impact of temperature and crystal orientation fabric on the dynamics of mountain glaciers and ice streams J. Glaciol. (IF 3.024) Pub Date : 2020-06-29 Kate Hruby; Christopher Gerbi; Peter Koons; Seth Campbell; Carlos Martín; Robert Hawley
Streaming ice accounts for a major fraction of global ice flux, yet we cannot yet fully explain the dominant controls on its kinematics. In this contribution, we use an anisotropic full-Stokes thermomechanical flow solver to characterize how mechanical anisotropy and temperature distribution affect ice flux. For the ice stream and glacier geometries we explored, we found that the ice flux increases
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Understanding the interrelationships among mass balance, meteorology, discharge and surface velocity on Chhota Shigri Glacier over 2002–2019 using in situ measurements J. Glaciol. (IF 3.024) Pub Date : 2020-06-23 Arindan Mandal; Alagappan Ramanathan; Mohd. Farooq Azam; Thupstan Angchuk; Mohd Soheb; Naveen Kumar; Jose George Pottakkal; Sarvagya Vatsal; Somdutta Mishra; Virendra Bahadur Singh
The Himalayan glaciers contribute significantly to regional water resources. However, limited field observations restrict our understanding of glacier dynamics and behaviour. Here, we investigated the long-term in situ mass balance, meteorology, ice velocity and discharge of the Chhota Shigri Glacier. The mean annual glacier-wide mass balance was negative, −0.46 ± 0.40 m w.e. a−1 for the period 2002–2019
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