Ice Segregation Research Articles

Removal of methylene blue from water by graphene oxide aerogel: thermodynamic, kinetic, and equilibrium modeling

Existence of many functional groups on graphene oxide sheets offers potential applications for the removal of environmental pollutants such as heavy metals and dyes. Moreover, materials with aligned porosity in the micrometer range could further enhance the adsorption capability by providing more adsorption sites. In this paper, the performance of graphene oxide aerogel (GOA) prepared by ice segregation induced self-assembly method was investigated as an adsorbent to remove methylene blue (MB) from aqueous solutions. The adsorbent was characterized by XRD, FTIR, TEM, SEM, EDX, and BET. The results showed that GOA has extremely high adsorption capacity for removal of MB. The equilibrium of MB removal process by GOA was well described by the Langmuir isotherm model, with a maximum adsorption capacity of 416.6667 mg g−1. The results of the thermodynamic investigations indicated that the adsorption reactions were spontaneous (ΔG° 0) and the adsorption kinetics of MB on GOA was best fitted to the pseudo-second-order model.

Spatiotemporal dynamics of wetted soils across a polar desert landscape

AbstractLiquid water is scarce across the landscape of the McMurdo Dry Valleys (MDV), Antarctica, a 3800 km2ice-free region, and is chiefly associated with soils that are adjacent to streams and lakes (i.e. wetted margins) during the annual thaw season. However, isolated wetted soils have been observed at locations distal from water bodies. The source of water for the isolated patches of wet soil is potentially generated by a combination of infiltration from melting snowpacks, melting of pore ice at the ice table, and melting of buried segregation ice formed during winter freezing. High resolution remote sensing data gathered several times per summer in the MDV region were used to determine the spatial and temporal distribution of wet soils. The spatial consistency with which the wet soils occurred was assessed for the 2009–10 to 2011–12 summers. The remote sensing analyses reveal that cumulative area and number of wet soil patches varies among summers. The 2010–11 summer provided the most wetted soil area (10.21 km2) and 2009–10 covered the least (5.38 km2). These data suggest that wet soils are a significant component of the MDV cold desert land system and may become more prevalent as regional climate changes.

Freezing colloidal suspensions: periodic ice lenses and compaction

AbstractRecent directional solidification experiments with aqueous suspensions of alumina particles (Anderson & Worster, Langmuir, vol. 28 (48), 2012, pp. 16512–16523) motivate a model for freezing colloidal suspensions that builds upon a theoretical framework developed by Rempel et al. (J. Fluid Mech., vol. 498, 2004, pp. 227–244) in the context of freezing soils. Ice segregates from the suspension at slow freezing rates into discrete horizontal layers of particle-free ice, known as ice lenses. A portion of the particles is trapped between ice lenses, while the remainder are pushed ahead, forming a layer of fully compacted particles separated from the bulk suspension by a sharp compaction front. By dynamically modelling the compaction front, the growth kinetics of the ice lenses are fully coupled to the viscous flow through the evolving compacted layer. We examine the periodic states that develop at fixed freezing rates in a constant, uniform temperature gradient, and compare the results against experimental observations. Congruent with the experiments, three periodic regimes are identified. At low freezing rates, a regular periodic sequence of ice lenses is obtained; predictions for the compacted layer thickness and ice-lens characteristics as a function of freezing rate are consistent with experiments. At intermediate freezing rates, multiple modes of periodic ice lenses occur with a significantly diminished compacted layer. When the cohesion between the compacted particles is sufficiently strong, a sequence of mode-doubling bifurcations lead to chaos, which may explain the disordered ice lenses observed experimentally. Finally, beyond a critical freezing rate, the regime for sustained ice-lens growth breaks down. This breakdown is consistent with the emergence of a distinct regime of ice segregation found experimentally, which exhibits a periodic, banded structure that is qualitatively distinct from ice lenses.

Cave development by frost weathering

This paper deals with the description and genesis of a special type of shelter cave. In German they are termed Auswitterungshöhlen which goes back to the 19th century and the genesis is supposed to be related to frost weathering, but to our knowledge, detailed studies are missing so far. This type of cave is very common in the area of investigation that comprises pre-Alpine and Alpine regions in the north-eastern part of the Eastern Alps: They make up 32% of the 5138 registered caves but surprisingly they entirely developed in carbonate rocks. Although most of them are smaller than a dozen metres, some have lengths of more than 50m and entrances can be more than 100m wide or similarly high. Besides general observations that lead to a list of characteristics for these caves, two of them in a pre-Alpine setting were studied in-depth. A detailed map, descriptions, and measurements concerning cave morphology, host rock geology, and climate are given. The thickness and composition of clastic sediments were investigated by small trenches and electric resistivity measurements. Sediment thicknesses reach up to 2m inside the caves and below the entrances. For one year nets were installed to measure rockfall in both caves. In warm periods generally less than 5g/month of debris could be collected, but a few 100g/month for frost periods. This strong correlation and the significant amount of debris together with other observations suggest that frost weathering is an on-going and very important process for the formation of these caves. Grain-size distribution of the collected debris argues for the activity of both microgelivation and ice segregation. Therefore we suggest that the term frost weathering caves should be used for shelter caves whose genesis is related to frost weathering. As dissolution seems to be of marginal importance for the genesis they are a paradox as they develop in karstic rock but have pseudokarst features.

Feasibility of Ice Segregation Location by Acoustic Emission Detection: A Laboratory Test in Gneiss

Large slope failures in steep alpine bedrock present significant geological hazards. Ice segregation is thought to be one of the mechanisms involved in high-mountain bedrock fracture but has not been reproduced experimentally in hard, intact rock. Here, we report results from a 3 month freezing experiment that aimed to reproduce ice-lens growth at the interface between the active layer and permafrost in a 15 cm cube of hard, intact rock (Arolla gneiss). Monitoring of acoustic emissions (AEs) recorded the propagation of microcracks horizontally through the block, resulting in a continuous and thick macrocrack near the base of the artificial active layer. Microcracking occurred within an approximate temperature range of −0.5 °C to −2.7 °C, consistent with ice segregation theory. Hypocentres of recorded AE events were concentrated in a 40 mm thick band between depths of 4.5 and 8 cm in the block. The band approximately coincides with the frozen fringe and indicates that ice segregation can induce micro- and macrocracking in gneiss. Copyright © 2014 John Wiley & Sons, Ltd.

A Procedure to Determine the Optimal Sensor Positions for Locating AE Sources in Rock Samples

Within a research work aimed to better understand frost weathering mechanisms of rocks, laboratory tests have been designed to specifically assess a theoretical model of crack propagation due to ice segregation process in water-saturated and thermally microcracked cubic samples of Arolla gneiss. As the formation and growth of microcracks during freezing tests on rock material is accompanied by a sudden release of stored elastic energy, the propagation of elastic waves can be detected, at the laboratory scale, by acoustic emission (AE) sensors. The AE receiver array geometry is a sensitive factor influencing source location errors, for it can greatly amplify the effect of small measurement errors. Despite the large literature on the AE source location, little attention, to our knowledge, has been paid to the description of the experimental design phase. As a consequence, the criteria for sensor positioning are often not declared and not related to location accuracy. In the present paper, a tool for the identification of the optimal sensor position on a cubic shape rock specimen is presented. The optimal receiver configuration is chosen by studying the condition numbers of each of the kernel matrices, used for inverting the arrival time and finding the source location, and obtained for properly selected combinations between sensors and sources positions.

J0320504 マイクロ波焼結によるバイモーダル多孔質SiCの作製([J032-05]ポリマー・セラミックス・メタル多孔質材料の開発と応用(5),材料力学部門)

A bi-modal porous SiC with cylindrical pores and communicated pores were fabricated through unidirectional solidification of water slurry containing CO_2 gas and microwave sintering. The cylindrical pores were formed during the unidirectional solidification under reduced pressure and a composite of ice and SiC powder was obtained. Since the composite was formed by segregation of ice during the solidification, a communicated structure of ice was obtained. The ice was removed by vacuum freeze drying method. The porous bulk with cylindrical pores and communicated pores was sintered using microwave sintering for 5 minutes. Since the dielectric loss factor for SiC is larger than that of the other ceramics, a rapid heating of SiC bulk can be achieved by microwave sintering. The porosity and pore size was well controlled by the pressure during the solidification and sintering time. The degree of shrinkage can be controlled by adding a sintering agent.

14C AGE, STABLE ISOTOPE COMPOSITION AND POLLEN ANALYSIS OF MASSIVE ICE, BOVANENKOVO GAS FIELD, CENTRAL YAMAL PENINSULA

The origin of the massive ice is important for understanding the Quaternary history of the Yamal region and to predict the occurrence of massive ice, which is important for gas exploration and the development of infrastructure. Massive ice bodies occur in the Bovanenkovo gas field area within sediments such as layers, laccoliths, rods and lenses. Maximal thickness of the tabular ice is 28,5 m; mean thickness is about 8 m. Deposits of the third terrace underlying and overlapping the tabular ice had been formed from 25 ka BP to 20 ka BP, according to 14C dates. Oxygen-isotope values (δ18О) of massive ices are ranged from 12, 49‰ up to -22, 95‰. Deuterium (δD) values vary from -91, 7‰ up to -177, 1‰. Deuterium excess (dexc) changes from 3, 4 to 10, 6‰. Both homogenous and contrast distribution δ18О and (δD) vs. depths in massive ice bodies evidences the segregated and/or infiltrated-segregated manner of ice formation. Pollen, spores and algae spectra from ice are similar to pollen characteristics of modern lacustrine and coastal floodplain sediments in the area. The ingression of cold seawaters on a coastal flood plain caused freezing and ice segregation, with the formation of extensive ice layers under the large but shallow lakes. As a result, syngenetic and genetically heterogeneous ice, such as: segregated, infiltrated-segregated, lake bottom congelation ice etc. was formed.

Lithalsa distribution, morphology and landscape associations in the Great Slave Lowland, Northwest Territories, Canada

Lithalsas are permafrost mounds formed by ice segregation in mineral-rich soil that occur within the zone of discontinuous permafrost. Nearly 1800 lithalsas were mapped using archival aerial photographs within the Great Slave Lowland, Northwest Territories, Canada. These are up to 8m high and several hundred meters in length and width. One lithalsa, examined by electrical resistivity and boreholes, rises 4 to 6m above an adjacent peatland, shows clear evidence of ice-segregation at depth and ground heave of between 2.5 and 4.0m, and is estimated to have formed within the past 700years. Regionally, lithalsas are typically located adjacent to ponds and streams with mature forms vegetated by deciduous (birch) forest or mixed (birch and spruce) forest with a herb–shrub understory and include circular, crescentic and linear forms. They are abundant within the Lowland region, which contains widespread glaciolacustrine, lacustrine and alluvial fine-grained sediments. The lithalsas are most common within the first few tens of meters above the present level of Great Slave Lake, indicating that many are late Holocene, and some less than 1000years, in age. A comparison with lithalsas in contemporary environments reveals that comparatively warm but extensive discontinuous permafrost, fine-grained sediments (alluvial, lacustrine, marine or glaciomarine), and available groundwater supply provide the climatic and hydro-geological parameters for the development of lithalsas in permafrost terrain. The identification of lithalsas in this region is important given their sensitivity to climate change and potential hazards to northern infrastructure upon thawing.

Paleo-pedological record of the Rocourt pedosequence at Veldwezelt–Hezerwater (Belgian Pleistocene loess belt): Part 2 — Soil formation

As the environment influences soil formation, Quaternary loess–paleosols provide an important, yet complex source on former climate and vegetation conditions. This study revises the paleopedological record of the Rocourt-complex, the pedostratigraphic marker for the Eemian and early Weichselian in the Belgian loess belt. Depth functions were established from an exceptionally well-preserved, in-situ sequence. Based on soil micromorphological features, total element contents, iron fractions and carbon content a reconstruction was made of the polygenetic formation of the Rocourt soil. Results indicate that only by combining multiple soil features, consistent information could be obtained. Furthermore, this study shows that cryogenic processes, transport of colloids, iron dynamics, redox-conditions, organic matter formation and biological activity were major soil forming processes. The hypothesis of six major stages of soil formation under varying climatic conditions was most supported by the data. During the warm to temperate oceanic climate of the Eemian, a strongly weathered argic horizon was formed. This horizon was later disrupted by reticulate ice segregation and stagnogley during the severe and prolonged cold conditions of the first cold stadial following the Eemian. Weak soil formation, during the relatively short continental St. Germain I interstadial, subsequently formed cambic soil properties and a humiferous horizon in a mixture of local and new sediments. These soils were disrupted by fragipan Formation, with its associated cryogenic structure, banded eluviation and redoxfront, during the succeeding stadial with periglacial conditions. During the St. Germain II, another A horizon formed in new, calcareous material during more stable climatic conditions, allowing organic matter build-up, eluviation of smectite and formation of pedogenetic iron. During the evolution from this warmer climate with forest or forested steppe to eventually periglacial open tundra, an accretionary humiferous soil concluded the last episode of soil formation before the onset of pleniglacial Weichselian conditions.

Modeling permafrost extension in a rock slope since the Last Glacial Maximum: Application to the large Séchilienne landslide (French Alps)

Recent dating performed on large landslides in the Alps has revealed that the initiation of instability did not immediately follow deglaciation but occurred several thousand years after ice down-wastage in the valleys. This result indicates that debuttressing is not the immediate cause of landslide initiation. The period of slope destabilization appears to coincide with the wetter and warmer Holocene Climatic Optimum, indicating a climatic cause of landslide triggering, although the role of seismic activity cannot be ruled out. A phenomenon which may partly explain the delay between valley deglaciation and gravitational instability is the temporal persistence of thick permafrost layers developed in the Alps since the Last Glacial Maximum (LGM). This hypothesis was tested through 2D thermal numerical modeling of the large Séchilienne landslide (Romanche valley, French Alps) using plausible input parameter values. Simulation results suggest that permafrost vanished in the Séchilienne slope at 10 to 11ka, 3000 to 4000years following the total ice down-wastage of the Romanche valley at 14.3ka. Permafrost persistence could have contributed to the failure delay by temporally strengthening the slope. Numerical simulations also show that the permafrost depth expansion approximately fits the thickness of ground affected by gravitational destabilization, as deduced from geophysical investigations. These results further suggest that permafrost development, associated with an ice segregation mechanism, damaged the rock slope and influenced the resulting landslide geometry.

Environmental controls of frost cracking revealed through in situ acoustic emission measurements in steep bedrock

Frost cracking, the breakdown of rock by freezing, is one of the most important mechanical weathering processes acting on Earth's surface. Insights on the mechanisms driving frost cracking stem mainly from laboratory and theoretical studies. Transferring insights from such studies to natural conditions, involving jointed bedrock and heterogeneous thermal and hydrological properties, is a major challenge. We address this problem with simultaneous in situ measurements of acoustic emissions, used as proxy of rock damage, and rock temperature/moisture content. The 1 year data set acquired in an Alpine rock wall shows that (1) liquid water content has an important impact on freezing‐induced rock damage, (2) sustained freezing can yield much stronger damage than repeated freeze‐thaw cycling, and (3) that frost cracking occurs over the full range of temperatures measured extending from 0 down to −15°C. These new measurements yield a slightly different picture than previous field studies where ice segregation appears to play an important role.

Circular, Cryogenic Structures from the Hirnantian Deglaciation Sequence (Anti-Atlas, Morocco)

Abstract More than a hundred circular structures are observed at the topmost part of the Late Ordovician glaciogenic record in the central Anti-Atlas, southern Morocco. The structures were formed in the outer glaciated platform and characterize the Hirnantian deglaciation sequence. They are distributed within a 20 meter thick stratal interval and, at present, relicts of them still occupy several square kilometers in map view. The circular to ovoidal structures, which comprise fluvial sandstone beds and are sealed by shallow marine strata, occur in closely spaced clusters. They are 13–320 m in diameter, with half of them in the 40–90 m range. Stratal wedging and bending, as well as extensional and reverse centimeter- to meter-scale soft-sediment fractures, demonstrate that formation processes initially involved synsedimentary uplifts. Subsequent subsidence and collapse resulted in the formation of circular structures, which essentially correspond to localized depocenters in the form of small-scale sag basins. Regarding the overall deglaciation context, the circular structures are interpreted as periglacial in origin, with vertical movements ascribed to cryogenic processes involving the growth and then decay of bodies of segregation ice. The size and diameter distributions, which are comparable to the recent (Younger Dryas) and current lithalsa structures, suggest that Hirnantian circular features relate to similar genetic processes and can be referred to as lithalsa-like structures. A conceptual emplacement model is proposed, which considers that a long-term sedimentary aggradation over the fluvial plain prevented any significant landforms (either a bump or a depression) from being expressed at the depositional surface at the time of the circular structure formation. The Hirnantian lithalsa-like structures constitute firm evidence for a Late Ordovician discontinuous permafrost during the deglaciation stage. Assuming that the late Quaternary meridional zonation is valid, it suggests the Anti-Atlas was at latitudes in the 55–65° interval. If combined with the rare pingo structures described in the literature, which attest that coeval continuous permafrost conditions occurred at higher paleo-latitudes, the Moroccan circular structures provide evidence for an alternate South Pole position during the Hirnantian (444 Ma).

Physical approach to mechanism of ice segregation by Keisukea japonica Miq., Lamiaceae

シソ科植物「シモバシラ」による氷晶析出機構を，野外観測や室内実験を通して，物理現象として説明することを試みた．シモバシラは，野外では生きた根系が土壌水を，室内実験では根系のない生きた茎や死んだ茎が容器の水を吸引して，茎の木部表面から多くの薄い板状の氷晶を放射状に析出した．その結果，吸水や氷晶析出は，根系とは無関係に，茎の生死を問わず，木部の構造によって起こることが示された．木部表面には，電子顕微鏡画像から1μm 大のピット（壁孔）が見つかった．以上のことから，このピットによって木部表面にある氷が木部内部への侵入を阻止されると，ピットの大きさから氷〜水界面の過冷却度（界面の温度と平衡温度との差）は0.11K，界面の間隙水圧は−1.4×105Paと試算される．この吸引圧が駆動力となり，土壌水は根系や茎内部を経て木部表面に移動して凍結し，氷晶が木部表面から外に向かって連続して成長する．仮に，木部内部へ氷が侵入しても，放射柔組織や導管のピットが同様の役割をすると考えられる．析出は，最大析出速度とΔTa（冷却温度Taと平衡温度との差）との関係で，茎の透水係数や氷の熱伝導係数などを反映した直線よりΔTaが大きい範囲で起こると考えられる．

Cryogenic Process to Elaborate Poly(ethylene glycol) Scaffolds. Experimental and Simulation Studies

Porous materials are of great importance because of their multiple applications in pharmacy, catalysis, and biomedicine among others. Ice segregation induced self-assembly (ISISA) is a cryogenic technique that uses the ice as a template that forms upon immersion of a polymer solution into liquid nitrogen to obtain highly porous materials. Some highlights of this technique are its versatility, simplicity, and control over the final structure of the produced material; besides, no organic solvents are used during the process, and the material can be used without the need of further cleaning. In this contribution, the elaboration of scaffolds using a poly(ethylene glycol) aqueous solutions by an ice-template process has been studied from experimental and theoretical viewpoints. The experimental study of the process parameters, such as immersion velocity and a prescribed freezing front on the morphology, was carried out. Simulations were performed to understand the ISISA process by calculating temperature profiles and pore size as a function of time. The most important result of this study was the effect of freezing rate on pore size. The technique was optimized such that a recipe is proposed to form materials with 1–100 μm pore sizes.

Mudboil and ice‐wedge dynamics investigated by electrical resistivity tomography, ground temperatures and surface movements in svalbard

Arctic tundra surfaces are dominated by a variety of patterned ground forms. Whereas a large number of studies have described morphology, structure and processes of patterned ground, few have monitored detailed patterned ground dynamics and subsurface environments continuously. We applied electrical resistivity tomography (ERT) to understand near‐surface conditions of two types of patterned ground, ice‐wedge polygons and mudboils in Svalbard, where periglacial processes associated with permafrost are intensively monitored. Automated monitoring shows surface movement characterized by annual cycles of frost heave and thaw settlement, the amounts and rates of which are influenced by the intensity of ice segregation. A time series of ERT shows (1) a distinct resistivity boundary delimiting the active‐layer depth, (2) seasonal variation in resistivity controlled by thermo‐hydrological dynamics and (3) spatial variation in resistivity reflecting desiccation in summer and intensive ice segregation in winter. These results demonstrate ERT as a useful complementary technique for monitoring active‐layer depths and near‐surface hydrological conditions at periglacial patterned ground sites, where automated soil thermal and moisture measurements are limited.

Periodic Ice Banding in Freezing Colloidal Dispersions

Concentrated colloidal alumina dispersions were frozen in a directional solidification apparatus that provides independent control of the freezing rate and temperature gradient. Two distinct steady-state modes of periodic ice banding were observed in the range of freezing rates examined. For each mode, the wavelength between successive bands of segregated ice decreases with increasing freezing rate. At low freezing rates (0.25-3 μm s(-1)), the ice segregates from the suspension into ice lenses, which are cracklike in appearance, and there is visible structure in the layer of rejected particles in the unfrozen region ahead of the ice lenses. In this regime, we argue that compressive cryosuction forces lead to the irreversible aggregation of the rejected particles into a close-packed cohesive layer. The temperature in the aggregated layer is depressed below the bulk freezing point by more than 2 °C before the ice lenses are encountered; moreover, this undercooled region appears as a light-colored layer. The magnitude of the undercooling and the color change in this region both suggest the presence of pore ice and the formation of a frozen fringe. The possibility of a frozen fringe is supported by a quantitative model of the freezing behavior. At intermediate freezing rates, around 4 μm s(-1), the pattern of ice segregation is disordered, coinciding with the disappearance of the dark- and light-colored layers. Finally, at high freezing rates (5-10 μm s(-1)), there is a new mode of periodic ice banding that is no longer cracklike and is absent of any visible structure in the suspension ahead of the ice bands. We discuss the implications of our experimental findings for theories of ice lensing.

In Situ Precipitation of Amorphous Calcium Phosphate and Ciprofloxacin Crystals during the Formation of Chitosan Hydrogels and Its Application for Drug Delivery Purposes

The immobilization of more than one single substance within the structure of a biocompatible polymer provides multifunctional biomaterials with attractive and enhanced properties. In the context of bone tissue engineering, it could be of great interest to synthesize a biomaterial that simultaneously contains amorphous calcium phosphate (ACP), to favor calcium and phosphate precipitation and promote osteogenesis, and an antibiotic such as ciprofloxacin (CFX) that can, eventually, avoid infections resulting after surgical scaffold implantation. However, the co-immobilization of multiple substances is by no means a trivial issue because of the enhanced number of interactions that can take place. One of the main issues is controlling not only the diverse solid forms that individual substances can eventually adopt, but also the forces responsible for the self-organization of the individual components. The latter determines whether phase-separated structures or conjugated architectures are obtained and, consequently, may dramatically affect their functionality. Herein, we have observed-by SEM, TEM, and solid-state NMR-that enzymatically-assisted coprecipitation of ACP and CFX resulted in phase-separated structures. Thus, CFX crystals showed identical morphology to that obtained in the absence of ACP, but the size was smaller. Neither the size nor the morphology of ACP exhibited significant differences whether precipitated with or without CFX, but, in the former case, ACP was stabilized over a wider range of pH and temperature. Finally, by using this methodology and the ice segregation induced self-assembly process (ISISA), we have successfully co-immobilized ACP and CFX in chitosan-based scaffolds. Interestingly, the presence of ACP exerted significant control on the CFX release from these materials.

Periglacial weathering and headwall erosion in cirque glacier bergschrunds

Glaciers produce cirques by scouring their beds and sapping their headwalls, but evidence to constrain models of these processes has been elusive. We report a suite of environmental measurements from three cirque glacier bergschrunds, including the first temperature series recorded at depth throughout most of an annual cycle. Compared to the ambient air, the bergschrunds were colder in summer and warmer in winter. Freeze-thaw cycles were rare, and relatively stable subfreezing temperatures persisted from November until May. Using a model for rock fracturing driven by ice segregation, we demonstrate that favorable conditions for fracturing occur not only on the headwall above the glacier, but also within the bergschrund, where periglacial weathering and glacial transport can act together to drive cirque headwall retreat. A small (∼3 °C) year-round decrease in temperatures to conditions more typical of the Pleistocene would likely intensify the weathering process. Though so far ignored in all glacial landscape evolution models, the bergschrund likely plays an essential role in the sculpting of alpine landscapes.

The dielectric permittivity of terrestrial ground ice formations: Considerations for planetary exploration using ground‐penetrating radar

Exploration of the polar ice caps and apparent glacial and periglacial landforms on Mars will aid our understanding of its ancient climate conditions and the history of water on the planet. Given that ground‐penetrating radar (GPR) is likely to be used to understand these features, we investigated the real component of the complex dielectric permittivity of stratified segregation ice, non‐stratified segregation ice, and polygonal ice wedge deposits in the Canadian Arctic. We acquired moveout profiles with a 450 MHz GPR on ground ice formations that had active layer sediments excavated prior to surveying. Using ice core data collected from these sites, we found that the volumetric fraction of ice plays the greatest role in defining the dielectric permittivity of the deposit and that it can be described using a modified complex refractive index method (CRIM) dielectric mixing model. Using the modified CRIM model, we estimate the dielectric permittivity of several ground ice deposits on Earth and present further estimates for similar features on Mars using permittivity values for Martian sediments derived from both theory and laboratory methods.