Ice wedge
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Role of ground ice dynamics and ecological feedbacks in recent ice wedge degradation and stabilization Open
Ground ice is abundant in the upper permafrost throughout the Arctic and fundamentally affects terrain responses to climate warming. Ice wedges, which form near the surface and are the dominant type of massive ice in the Arctic, are partic…
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Deep Convolutional Neural Networks for Automated Characterization of Arctic Ice-Wedge Polygons in Very High Spatial Resolution Aerial Imagery Open
The microtopography associated with ice-wedge polygons governs many aspects of Arctic ecosystem, permafrost, and hydrologic dynamics from local to regional scales owing to the linkages between microtopography and the flow and storage of wa…
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Climate Sensitivity of High Arctic Permafrost Terrain Demonstrated by Widespread Ice-Wedge Thermokarst on Banks Island Open
Ice-wedge networks underlie polygonal terrain and comprise the most widespread form of massive ground ice in continuous permafrost. Here, we show that climate-driven thaw of hilltop ice-wedge networks is rapidly transforming uplands across…
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Pathways of ice-wedge degradation in polygonal tundra under different hydrological conditions Open
Ice-wedge polygons are common features of lowland tundra in the continuous permafrost zone and prone to rapid degradation through melting of ground ice. There are many interrelated processes involved in ice-wedge thermokarst and it is a ma…
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Geophysical estimation of shallow permafrost distribution and properties in an ice-wedge polygon-dominated Arctic tundra region Open
Shallow permafrost distribution and characteristics are important for predicting ecosystem feedbacks to a changing climate over decadal to century timescales because they can drive active layer deepening and land surface deformation, which…
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Ice fabric in an Antarctic ice stream interpreted from seismic anisotropy Open
Here we present new measurements of an anisotropic ice fabric in a fast moving (377 ma −1 ) ice stream in West Antarctica. We use ∼6000 measurements of shear wave splitting observed in microseismic signals from the bed of Rutford Ice Strea…
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Past climate and continentality inferred from ice wedges at Batagay megaslump in the Northern Hemisphere's most continental region, Yana Highlands, interior Yakutia Open
Ice wedges in the Yana Highlands of interior Yakutia – the most continental region of the Northern Hemisphere – were investigated to elucidate changes in winter climate and continentality that have taken place since the Middle Pleistocene.…
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A Wedge Mechanism for Summer Surface Water Inflow Into the Ross Ice Shelf Cavity Open
Ocean heat supply to ice shelves has a significant impact on the long‐term evolution of ice shelves. Intrusions of warm surface waters into the frontal region of the cavity, known as “Mode 3” circulation, are capable of melting the ice she…
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Mapping the ice‐bed interface characteristics of Rutford Ice Stream, West Antarctica, using microseismicity Open
Flow dynamics of the ice streams that drain the Antarctic Ice Sheet are heavily influenced by processes at the bed. Natural seismic activity generated beneath an ice stream is associated with the motion of the ice over its bed and can be u…
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Recent Advances (2008–2015) in the Study of Ground Ice and Cryostratigraphy Open
Cryostratigraphy involves the description, interpretation and correlation of ground‐ice structures (cryostructures) and their relationship to the host deposits. Recent advances in the study of ground ice and cryostratigraphy concern permaf…
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Wave–ice interactions in the neXtSIM sea-ice model Open
In this paper we describe a waves-in-ice model (WIM), which calculates ice breakage and the wave radiation stress (WRS). This WIM is then coupled to the new sea-ice model neXtSIM, which is based on the elasto-brittle (EB) rheology. We high…
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Microtopographic control on the ground thermal regime in ice wedge polygons Open
The goal of this research is to constrain the influence of ice wedge polygon microtopography on near-surface ground temperatures. Ice wedge polygon microtopography is prone to rapid deformation in a changing climate, and cracking in the ic…
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Water Migration and Segregated Ice Formation in Frozen Ground: Current Advances and Future Perspectives Open
A characteristic of frozen ground is a tendency to form banded sequences of particle-free ice lenses separated by layers of ice-infiltrated soil, which produce frost heave. In permafrost, the deformation of the ground surface caused by seg…
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High potential for loss of permafrost landforms in a changing climate Open
The presence of ground ice in Arctic soils exerts a major effect on permafrost hydrology and ecology, and factors prominently into geomorphic landform development. As most ground ice has accumulated in near-surface permafrost, it is sensit…
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Feedbacks Between Surface Deformation and Permafrost Degradation in Ice Wedge Polygons, Arctic Coastal Plain, Alaska Open
In the past three decades, an abrupt, pan‐Arctic acceleration of ice wedge melting has transformed tundra landscapes, spurring the formation of hummock‐like features known as high‐centered polygons (HCPs). This rapid geomorphic transition …
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Evaluating integrated surface/subsurface permafrost thermal hydrology models in ATS (v0.88) against observations from a polygonal tundra site Open
Numerical simulations are essential tools for understanding the complex hydrologic response of Arctic regions to a warming climate. However, strong coupling among thermal and hydrological processes on the surface and in the subsurface and …
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Assessment of the Ice Wedge Polygon Current State by Means of UAV Imagery Analysis (Samoylov Island, the Lena Delta) Open
Modern degradation of Arctic permafrost promotes changes in tundra landscapes and leads to degradation of ice wedge polygons, which are the most widespread landforms of Arctic wetlands. Status assessment of polygon degradation is important…
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Ice‐wedge polygon dynamics in Svalbard: Lessons from a decade of automated multi‐sensor monitoring Open
Twelve years of continuous monitoring of diverse ground properties reveals the dynamics of three ice wedges and adjacent ground in a low‐centered polygon area in Svalbard. The monitoring documented ground displacements, the timing of crack…
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Holocene thermokarst and pingo development in the Kolyma Lowland (NE Siberia) Open
Ground ice and sedimentary records of a pingo exposure reveal insights into Holocene permafrost, landscape and climate dynamics. Early to mid‐Holocene thermokarst lake deposits contain rich floral and faunal paleoassemblages, which indicat…
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Wave-induced stress and breaking of sea ice in a coupled hydrodynamic discrete-element wave–ice model Open
In this paper, a coupled sea ice–wave model is developed and used to analyze wave-induced stress and breaking in sea ice for a range of wave and ice conditions. The sea ice module is a discrete-element bonded-particle model, in which ice i…
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Viscoelastic Modeling of Nocturnal Thermal Fracturing in a Himalayan Debris‐Covered Glacier Open
Recent observations suggest that the nocturnal thermal fracturing of ice occurs at relatively warm temperatures (above −15 °C) at a high‐altitude Himalayan glacier system unless the ice is shielded by a debris mantle. Here we estimate the …
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Hydroelastic response of an ice sheet with a lead to a moving load Open
The hydroelastic symmetric response of a floating ice sheet caused by a pressure moving either in the ice lead or on the infinite ice sheet with a crack (a lead of zero width) is investigated. The ice sheet is modeled as a viscoelastic thi…
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Understanding the relative importance of vertical and horizontal flow in ice-wedge polygons Open
Ice-wedge polygons are common Arctic landforms. The future of these landforms in a warming climate depends on the bidirectional feedback between the rate of ice-wedge degradation and changes in hydrological characteristics. This work aims …
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Northeast Siberian Permafrost Ice‐Wedge Stable Isotopes Depict Pronounced Last Glacial Maximum Winter Cooling Open
Stable isotopes (δ 18 O, δD) of wedge ice hold potential to reconstruct past winter climate conditions. Here, we present records of the marine isotope stages (MIS) 3 and 2 including the last Glacial maximum (LGM) from Bol’shoy Lyakhovsky I…
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Glacitectonic rafts and their role in the generation of Quaternary subglacial bedforms and deposits Open
Landforms and sediments on the palaeo–ice stream beds of central Alberta record glacitectonic raft production and subsequent progressive disaggregation and moulding, associated substrate ploughing, and grooving. We identify a subglacial te…
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Evidence of multiple thermokarst lake generations from an 11 800‐year‐old permafrost core on the northern <span>S</span>eward <span>P</span>eninsula, <span>A</span>laska Open
Permafrost degradation influences the morphology, biogeochemical cycling and hydrology of Arctic landscapes over a range of time scales. To reconstruct temporal patterns of early to late Holocene permafrost and thermokarst dynamics, site‐s…
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Experimental study on surface wave modifications by different ice covers Open
A laboratory experimental study conducted in a freshwater wave flume installed in a refrigerated room characterized the modifications of wave propagation along on-site manufactured ice covers. Monochromatic surface waves of various amplitu…
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Modeling of ice pinnacle formation on Callisto Open
Callisto's pinnacle terrain has been interpreted to form through sublimation weathering of bedrock and subsequent deposition of the sublimated ice in local cold traps on peaks and crater rims. To investigate how these processes are affecte…
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Seismic Anisotropy of Temperate Ice in Polar Ice Sheets Open
We present a series of simple shear numerical simulations of dynamic recrystallization of two‐phase nonlinear viscous materials that represent temperate ice. First, we investigate the effect of the presence of water on the resulting micros…
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Atomistic and coarse-grained simulations reveal increased ice nucleation activity on silver iodide surfaces in slit and wedge geometries Open
Ice clouds can form at low and moderate supercooling through heterogeneous ice nucleation on atmospheric particles. Typically, the nucleation requires active sites with special chemical and physical properties, including surface topology a…