The Arctic is warming four times faster than the global average. Rising air and sea temperatures, coupled with a longer open-water season, are intensifying the thermal and mechanical erosion of ice-rich permafrost coastlines. This results in rapid land and permafrost loss, directly threatening sensitive coastal environments, local ecosystems, and cultural heritage sites. Herschel Island Qikiqtaruk (HIQ), in the northern Yukon (Canada) epitomizes these changes because of the presence of ice-rich permafrost and of critical infrastructure at the coastline. Yet, the latest erosion records stop in 2011 and do not include many of the sea ice record minima of the 21st century. This study reports on new 2D (planimetric) and 3D (volumetric) coastal erosion records along the permafrost coastline of HIQ. Using published data starting in 1952 and new high-resolution satellite imagery from 2000, 2011, and 2022, as well as airborne lidar datasets from 2013 and 2023, shoreline changes were analyzed over the past seven decades to quantify erosion trends and extend existing records. We find a significant increase in erosion rates in both planimetric and volumetric terms, particularly along the northern and western coasts of the island. Mean planimetric erosion rates increased from 0.68 ± 2.48 m/a (2000–2011) to 1.08 ± 1.50 m/a (2011–2022), reflecting a ~59% increase. Volumetric erosion rates averaged 30.43 m3/m/a (2013–2023), with peaks of up to 186.70 m3/m/a at sea-exposed high cliffs. Simpson Point features some of the strongest erosion in the east which its extension westward, threatening some of the basic support infrastructure of HIQ.

The Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), has conducted airborne radar campaigns since 1994 across Antarctica and Greenland, utilizing six different radar systems to study ice sheets and their interactions with climate, ocean and the solid Earth. Over the past three decades, AWI has collected more than one million profile-kilometres of radar data, covering approximately one quarter of the Antarctic and the Greenland Ice Sheet, respectively. In this review article, we describe AWI's airborne radar systems and their deployments over the Greenland and Antarctic Ice Sheet. Moreover, we summarize application and usage of AWI's radar systems, which provided crucial insights into e.g., ice dynamics, mass balance, and ancient landscapes buried beneath the ice. The integration of radar data with other geophysical methods has enhanced bathymetric models, improving predictions of ice–ocean interactions and ice-shelf stability and contributed to a better understanding of crustal and geological evolution of the Antarctic continent. As part of this paper, and to support scientific progress, AWI made its airborne radar data publicly accessible through the Radar Data over Polar Ice Sheets viewer hosted by the Marine Data Portal (https://marine-data.de/viewers/, last access: 19 April 2026) and PANGAEA (https://doi.org/10.1594/PANGAEA.972094; Eisen et al., 2024), ensuring compliance with FAIR (Findable, Accessible, Interoperable, Reusable) data principles. Future research will expand on these contributions, focusing on refining ice-sheet models and exploring new areas of glaciological and geological interest.

Multichannel ice-penetrating radar systems can be used to generate radar volumes: three-dimensional data structures that capture variability in backscattering intensity as a function of along-track position, two-way travel time and elevation angle. By digitizing surfaces within these data volumes, the production of wide-area, fine-resolution digital elevation models (DEMs) of the ice-bottom interface (measured through kilometres of ice) is now possible. This paper reviews this technique ('radar swath imaging'), explores its methodological principles, describes its operational requirements and highlights recent scientific advances enabled by radar swath imaging. Observations of glacier and substrate morphology and physical properties inferred from swath data have already been used to improve our understanding of ice-shelf melt, basal sliding and subglacial sediment and water transport. Lessons learned from these initial surveys should inform future data collection strategies, so that radar swath imaging can be deployed in the most productive way possible during upcoming major field campaigns, including the Fifth International Polar Year and beyond. This article is part of the Theo Murphy meeting issue 'Next generation ice-sheet bed measurements'.

Projections of Antarctica's sea-level contribution depend on future changes in surface mass balance (SMB), yet it remains uncertain whether climate change has already impacted SMB on the East Antarctic Plateau, given diverging trends in prior studies. Using similar to 3,000 km of airborne radar data from western Dronning Maud Land (DML), we reconstructed SMB over the past similar to 800 years (1209-2024 C.E.) and found stable centennial averages before 1977, followed by a 21% increase in recent decades. This increase is spatially coherent despite strong small-scale variability driven by topography and wind redistribution, which can bias upscaling of firn core records. Integrating radar and firn core data at similar to 5 5 km2 scales reduces this bias. Our results show an increase in SMB in western DML over the last five decades. If sustained, it could help mitigate sea-level rise.

Snow cover influences sea ice thermodynamics and mass balance, making its distribution and properties critical to polar research. Grounded icebergs in coastal Antarctica substantially affect surface snow distribution and landfast sea ice patterns, which have received limited scientific attention. To address this gap, this study integrates airborne laser scanning observations with numerical snow transport simulations to investigate snow distribution on landfast ice around icebergs, emphasizing the influence of wind and iceberg size. Observations show that persistent wind directions shape characteristic snow patterns around icebergs, with substantial windward and lateral drifts and an elongated snow-depleted region in the lee. Data further reveal that snowdrift size scales nonlinearly with iceberg size, indicating reduced snow accumulation efficiency for larger icebergs, which simulations partially captured. This study also highlights the key role of wind direction shifts in reproducing measured snow distributions and suggests that the maximum extent of snowdrifts is constrained by peak wind speeds encountered on site. Together, our findings show that iceberg-induced snowdrifts connect ice shelf and fast ice dynamics, reflect local wind conditions and provide key insights into snow mass balance on Antarctic landfast sea ice.

Accurate estimation of landfast sea ice roughness is critical for climate modeling and safe Arctic over-ice travel, yet existing approaches rely on costly airborne surveys or sparse in-situ measurements, limiting spatial coverage and operational scalability. Here we show that high-resolution sea ice topography can be reconstructed directly from optical satellite imagery using a conditional diffusion framework. Our approach, RoughNet, learns to map 10 m Sentinel-2 multispectral images to locally normalized 1 m surface elevation residual fields, enabling fine-scale roughness characterization from widely available satellite data. Trained on airborne LiDAR data from two Arctic regions and evaluated on an unseen third Arctic region, the model generalizes across diverse ice conditions and partially reproduces small-scale topographic structure. The best-performing model achieves an out-of-domain root mean squared error of 9 cm while preserving the statistical and spectral properties of the underlying roughness field. These results demonstrate that generative diffusion models can recover physically meaningful surface structure from optical imagery alone, providing a scalable pathway for high-resolution sea ice mapping and roughness estimation in data-sparse environments.

Radio-echo sounding of polar ice masses has revealed extensive isochrones that have primarily been used to constrain paleo-accumulation rates, geothermal heat flux, and changes in ice-sheet dynamics in stable regions of the ice sheet. However, isochrones remain under-utilised for calibrating ice-sheet models over large spatial scales, particularly in areas far from the stable ice divide where isochrones are typically more disrupted and models likely perform less accurately. Here, we illustrate the utility of isochrones for constraining paleo-ice-sheet simulations in two off-divide areas of the East Antarctic Ice Sheet; the Wilkes Subglacial Basin (WSB) and the Dronning Maud Land (DML) regions. Using airborne radio-echo sounding data from both legacy and newly acquired surveys, and the three-dimensional, thermo-mechanically coupled Parallel Ice-Sheet Model (PISM), we show that traced and dated isochrones are essential for calibrating model simulations in faster-flowing regions of the ice sheet. Associated with this paper are two datasets of nine and seven newly traced isochrones spanning the Holocene and Last Interglacial (similar to 4.8-128.4 ka) across the WSB and DML sectors, respectively, which may be used in future modelling studies to assess the paleo-evolution of the East Antarctic Ice Sheet. Using a commonly traced isochrone dated at similar to 91 ka across both sectors, we simulate its modelled equivalent along two off-divide transects and discuss its utility for constraining the model. We highlight the influence of paleo-climate forcing and model parameterisation, which can lead to widely different model representations of isochrones despite producing reasonable present-day ice-sheet geometries that are consistent with observations. This study demonstrates that achieving a good present-day match in ice-sheet geometries in off-divide areas does not necessarily translate to an appropriate transient ice-sheet evolution in the model and thus emphasises the need to incorporate isochrones as boundary conditions in paleo-ice-sheet model simulations.

The mechanisms of drainage of supraglacial lakes are not yet fully understood. Here we present an indepth study of drainage characteristics of a 21km^2 large supraglacial lake in Northeast Greenland from its genesis in mid 1990s to 2023. We discuss the fracture modes involved in drainage and compare this to simulated principal stress fields. A particular focus of the presentation is the formation of gullies. Using high resolution optical satellite imagery (WV2 and Planet), we detect fracture networks at the surface. We find evidence for reactivation of former gullies in subsequent lake drainage events. In addition we present viscoelastic modelling of gullies at the surface that support the continued existence of open gullies at the surface. In vertical direction, we surveyed the glacier using airborne radio echo sounding in 2016, 2018 and 2021. This data reveals englacial channels and their remnants over the entire live span of the lake.

An effective spatial resolution of a few hundred kilometres, typically assessed for mass variations derived from GRACE/GRACE-FO data, is a major limitation for the rigorous investigation of local causes of mass variations. This is crucial for analyzing mass changes of the West Antarctic Ice Sheet, which is one of the tipping elements in the Earth’s climate system. In this region, ice mass changes occur on spatial scales smaller than the typical GRACE/GRACE-FO resolution. Furthermore, this is also the case for the solid-Earth deformation induced by ice load changes, which in turn can affect the glacier flow. Especially in the Amundsen Sea Embayment, mass changes due to the ongoing Glacial Isostatic Adjustment (GIA) have been postulated to vary on spatial scales smaller than 200 km and to feed back significantly on ice flow dynamics. Here, we present results from a data combination approach with a focus on the Amundsen Sea Embayment, West Antarctica. This approach utilizes data from GRACE/GRACE-FO and CryoSat-2 satellite altimetry with regional climate and firn model results over a time span of 10 years from 2011 to 2020. Improved GRACE/GRACE-FO gravity-field processing and a study area in a high latitude region, where the signal-to-noise is high, benefit a high spatial resolution of the results. One processing step is the smoothing of the input data sets in order to unify their different spatial resolution. We find a best fit of the combination results with independent GNSS observations by applying a Gaussian smoother of 135 km half-response width. The weighted rms difference is 3.8 mm/a in terms of estimated bedrock motion. It is almost twice as large when the input data sets are smoothed with a 300 km half-response filter. The determined effects of solid-Earth deformation may be a useful boundary information for GIA modelling in this region, e.g. for testing rheological models or (centennial) glacial histories.

The surface elevation of the Greenland Ice Sheet is constantly changing due to the interplay between surface mass balance processes and ice dynamics, each exhibiting distinct spatiotemporal patterns. Here, we employ satellite and airborne altimetry data with fine spatial (1 km) and temporal (monthly) resolutions to document this spatiotemporal evolution from January 2003 to August 2023. To estimate elevation changes of the Greenland Ice Sheet (GIS), we utilize radar altimetry data from CryoSat-2 and EnviSat, laser altimetry data from the ICESat and ICESat-2, and laser altimetry data from NASA's Operation IceBridge Airborne Topographic Mapper. We produce continuous monthly ice surface elevation changes from January 2003 to August 2023 on a 1 km grid covering the entire GIS. We estimate cumulative ice loss of 4352 Gt +/- 315 Gt (12.1 +/- 0.9 mm sea level equivalent) during this period, excluding peripheral glaciers. Between 2003 and 2023, the ice sheet land-terminating margin underwent a significant cumulative thinning of several meters. Ocean-terminating glaciers exhibited thinning between 20-40 m, with Jakobshavn Isbr ae experiencing an exceptional thinning of nearly 70 m. This dataset of fine-resolution altimetry data in both space and time will support studies of ice mass loss and will be useful for GIS modeling. To validate our monthly mass changes of the Greenland ice sheet, we use mass change from satellite gravimetry and mass change from the input-output method. On multiannual timescales, there is a strong correlation between the time series, with R values ranging from 0.88 to 0.92 (10.5061/dryad.s4mw6m9dh, Khan et al., 2025)

Radio-echo sounding provides the opportunity to study the internal architecture of ice sheets through imaging stratified englacial reflections, known as internal reflection horizons (IRHs). They represent consistent time horizons formed at the former ice-sheet surface and buried over time, thus reflecting the ice sheet's age–depth architecture. Their analysis allows crucial insights into past and present glaciological conditions, e.g. bed topography, surface and basal mass balance, and physical properties and ice dynamics. This study presents a comprehensive data set of IRHs and insight into the age–depth distribution in western Dronning Maud Land (DML), East Antarctica, spanning the Holocene to the Last Glacial Period (4.8–91.0 ka). Using data from various radar systems deployed by the Alfred Wegener Institute between 1996 and 2023, we traced and dated nine IRHs over an area of 450 000 km2. A precise age could be assigned to the IRHs by two-way travel time to depth conversion and employing radar forward modelling based on conductivity peaks of the EPICA DML ice core. Six IRHs correlate with the timing of past volcanic eruptions, and our findings suggest that most IRHs correspond to IRHs of similar age in other regions of East and West Antarctica, thus likely originating from the same physical reflectors at depth, although some could not be physically connected. This work enhances understanding of the englacial architecture and relationships with snow accumulation and ice-dynamic processes of this sector of the Antarctic ice sheet and provides boundary conditions for numerical ice flow models and paleoclimatic studies.

Abstract. Radio-echo sounding of polar ice masses have revealed extensive isochronal surfaces that have primarily been used to constrain paleo-accumulation rates, geothermal heat flux, and changes in ice-sheet dynamics in stable regions of the ice sheet. However, isochrones remain under-utilised to calibrate ice-sheet models over large spatial scales, particularly in areas far from the stable ice-sheet divide where englacial layering is more disrupted and models likely perform less accurately. Here, we illustrate the utility of isochrones to constrain paleo-ice-sheet simulations in two off-divide areas of the East Antarctic Ice Sheet; the Wilkes Subglacial Basin (WSB) and the Dronning Maud Land (DML) regions. Using airborne radio-echo sounding data from both legacy and newly acquired surveys, and the three-dimensional, thermo-mechanically coupled Parallel Ice-Sheet Model (PISM), we show that traced and dated isochrones are essential for calibrating ice-sheet model simulations in faster-flowing areas of the ice sheet. We highlight the imprint of paleo-climate forcing and model parameterisation that lead to widely different model representations of isochrones with comparable present day representations of ice sheet geometry. Associated with this paper are two datasets of 9 and 7 newly traced isochronal surfaces spanning the Holocene and Last Interglacial (∼4.8–128.4 ka) across the WSB and DML sectors, respectively, which may be used in future modelling studies to assess the paleo-evolution of the Antarctic Ice Sheet. This paper sits at the intersection of data-model integration and highlights further opportunities for using isochrones as boundary conditions in paleo-ice-sheet model simulations.

Here we present an extensive swath radar dataset collected in the onset region of the Northeast Greenland Ice Stream, surrounding the East Greenland Ice Core Project site (EGRIP). We produce a new digital elevation model (DEM) of the subglacial topography at a resolution of 25 m, covering a study area of 40 km by 60 km. The data was collected using the AWI airborne ultra-wideband radar system, in profiles mainly perpendicular to the ice flow direction with a spacing of 2 km so that the swaths overlapped. The high-resolution subglacial topography DEM shows subglacial landforms beneath an active ice stream, located approximately 600 km into the interior of the ice sheet. These landforms indicate spatially variable bed conditions which are partly reflected in the surface velocity field. Some features appear to be crag and tail formations up to 4 km in length, with steep stoss-side slopes and tapering lee-side tails which are oriented in the direction of ice flow. Megascale glacial lineations up to 7 km in length are evident, but appear restricted to the inner ice stream within the modern shear margins, where the ice flow velocity increases from approximately 11 m/a to 58 m/a. Meltwater channels curve around a high point in the topography, which are on the scale of tunnel valleys formed from subglacial meltwater incision. Seismic data located in a channel at the eastern shear margin indicates soft sedimentation inflow. In summary, differences in landform morphology can be seen within and outside of the ice stream shear margins, indicating that NEGIS ice flow may have been transitory in this region. This survey provides a new insight into the active subglacial environment of a Greenlandic ice stream, matching in quality surveys from ice-free land surface or marine areas. Further analysis will contribute to the understanding of how glacially sculpted landscapes are formed, as well as the effects of small-scale topography on the dynamics and the surface of the overlying ice sheet, in particular ice streams. Moreover, the dataset emphasises the usage of swath radar mapping of bedforms and thus a more widespread application of this method in all radar surveys.

The stability of the Antarctic Ice Sheet depends on ice flux into the ocean through major outlet glaciers, which is resisted by shear stresses in the lateral shear margins, both on grounded ice and on floating ice shelves. Within the tidal-flexure zone, where the ice sheet transitions from fully grounded to freely floating, ocean tides lead to a characteristic flexural pattern, which can be detected by radar satellites in differential interferograms. Here, we investigate how spatially heterogeneous elastic ice-shelf properties in the shear zones affect tidal flexure and whether a corresponding signature can be detected in satellite observations. We use the Young's modulus (which, among others, depends on ice temperature and/or ice-crystal orientation fabric and damage) as a bulk tuning variable for changing ice stiffness across shear zones and show that this leads to centimeter-scale deviations in vertical displacement, compared with a homogeneous elastic flexure model. Using the tidal-flexure zone of Priestley Glacier as an example, we compare homogeneous and heterogeneous flexure-model predictions with observations from 31 differential interferograms. After adjusting the local tide model and validating it with in situ GPS data, we find that a 5-fold reduction of the Young's modulus in the shear zone, i.e., an effective shear-zone weakening, reduces the root-mean-square error of predicted and observed vertical displacement by 33 % within the central part of the ice shelf. This suggests that satellite interferometry can detect changing ice stiffness across shear zones, with the potential to inform ice-flow models about the often unknown spatial variability in ice-shelf properties along the grounding zone.

The instability of the West Antarctic Ice Sheet (WAIS) is a tipping element in the climate system, and it is mainly dictated by changes in the ice flow behaviour of the outflow glaciers in the Amundsen Sea Embayment (ASE). Recent studies postulated that the vertical uplift of bedrock can delay the collapse of glaciers in this region. In West Antarctica, bedrock motion is largely caused by a fast viscoelastic response of the upper mantle to changes in ice loads over the last centuries. This glacial isostatic adjustment (GIA) effect is currently poorly understood, since Earth's rheology and the ice-loading history are both subject to large uncertainties in simulations. Moreover, results from data-driven approaches have not yet resolved GIA at a sufficient spatial resolution. We present a data-driven GIA estimate, based on data from GRACE/GRACE-FO (GRACE and GRACE-FO), CryoSat-2 altimetry, regional climate modelling, and firn modelling, which is the first to agree with independent vertical velocities in West Antarctica derived from global navigation satellite system (GNSS) data. Our data combination yields a maximum GIA bedrock motion rate of 43 +/- 7 mma-1 in the Thwaites Glacier region and agrees within uncertainties in the GNSS-derived rate. The data-driven GIA-related bedrock motion may be used in future simulation runs to quantify a potential delay of the collapse of the West Antarctic Ice Sheet due to the stabilization effects induced by GIA. Furthermore it may be used for testing rheological models with low upper-mantle viscosity in conjunction with centennial loading histories.

Abstract. Satellite radar altimetry has provided continuous observations of Antarctic Ice Sheet (AIS) surface elevation change since 1992. However, uncertainties in radar-derived elevation estimates remain substantial, primarily due to the influence of local surface topography and time-variable signal penetration into snow and firn. The launch of the ICESat-2 laser altimetry mission in late 2018 established a new benchmark for high-accuracy surface elevation measurements, enabling inter-comparison with radar altimetry results and improved assessment of associated uncertainties. In this study, we use the ICESat-2 measurements to evaluate radar altimetry-derived elevation change estimates from CryoSat-2 over the 6 905 000 km2 large and relatively flat interior of the AIS, where topography-related errors are small. We apply a suite of radar-specific correction methods to the CryoSat-2 measurements, including multiple retracking algorithms and empirical corrections for the time-variable surface and volume scattering of the radar signal. We analyse a 5.5-year overlap period between ICESat-2 and CryoSat-2 (April 2019-October 2024) to assess how the different correction methods influence the CryoSat-2 surface elevation change estimates and their uncertainties. ICESat-2 observations indicate a thickening of 97 ± 4 km3 yr-1, coinciding with several events of excess snowfall during 2019-2024. All CryoSat-2 solutions yield systematically lower thickening trends, with the smallest bias (0.6 ± 1.0 cm yr−1 or 42 km3 yr-1) obtained using the AWI-ICENet1 convolutional neural network retracker. The remaining trend differences correlate with the ICESat-2 trend signal itself. We discuss possible causes of these systematic differences, one of which is the hypothesis that temporal variations in radar signal penetration associated to temporal variations in snow properties continue to induce systematic errors in inferred surface elevation changes. If the mean trend difference here were representative of the entire grounded AIS (12 352 700 km2), it would correspond to an underestimation of AIS volume and mass trends by approximately 74 km3 yr−1 and 28 Gt yr−1, respectively. These results underscore the challenges of using radar altimetry to resolve subtle, long-term trends related to surface mass balance changes, while also demonstrating the potential of combined laser-radar altimetry analysis to reduce uncertainties in AIS volume and mass balance estimates.

Landfast sea ice fringes much of the coast of Antarctica and plays an important role for coastal ice–ocean–atmosphere interaction and ice shelf stability, as well as for the sea ice associated ecosystem. It is often characterized by embedded icebergs, which influence wind-driven snow distribution and properties. Using high-resolution data from an airborne multi-sensor survey over landfast sea ice in Atka Bay, Dronning Maud Land, in December 2022, we investigate the characteristics of extensive snow drifts around icebergs and their impact on flooding. An airborne quad-polarized, ultra-wideband microwave (UWBM) snow radar and laser scanner reveal persistent snow accumulation patterns around icebergs, with thick snow drifts on the windward side of icebergs, elongated lateral snow drifts parallel to the prevailing wind direction along their sides, and virtually snow-free regions with rough ice surfaces in their lee. The mass of the thick wind-facing and lateral snow drifts pushes the sea ice locally below sea level leading to flooding and slush formation at the base of the snow drifts. These heterogeneous snow–water–sea-ice interfaces cause increased cross-polarized backscatter due to depolarization in the UWBM radar returns, providing a means for slush detection by airborne radar surveys. Presence of slush is confirmed by ground-based electromagnetic induction sounding data as well as with in situ measurements. Our study documents the significant influence of icebergs on snow thickness variability and redistribution over landfast sea ice and for slush formation. Moreover, it demonstrates that the snow in the lee of icebergs is thin, resulting in high radar backscatter in SAR imagery. These insights improve our understanding of wind-driven snow distribution and its impact on flooding on iceberg-laden landfast sea ice, contributing to better assessments of snow transport, sea ice mass balance, and climate modeling around Antarctica.

Rapidly-flowing ice streams drain the interior of the Greenland Ice Sheet, currently accounting for around half of its annual mass loss. The Northeast Greenland Ice Stream (NEGIS) is one of the largest, recognisable almost 600 km inland, and extends close to the central ice divide. Numerical ice sheet models are unable to accurately reproduce the configuration of the NEGIS, but understanding its bed properties and spatial and temporal evolution is critical to predicting its future contribution to sea-level change. Here, we use swath radar imaging to create a high-resolution Digital Elevation Model of the bed close to where the NEGIS initiates. Surprisingly, this reveals a landscape interpreted to include mega-scale glacial lineations (MSGLs) that are often assumed to be indicative of rapid ice stream flow (100s m yr-1), under present-day flow velocities of only similar to 60 m yr-1. Given that MSGLs are thought to form under much higher flow velocities, their presence so far inland at an onset zone raises important questions about their formation and preservation under ice streams, as well as past configurations of the NEGIS. Elongate bedrock landforms outside the current shear margins also suggest that the NEGIS was wider than its present configuration at some point in the past.

The stability of polar ice sheets is governed by the seaward movement of ice streams which is decelerated by resistance originating from lateral shear zones. We explore the impact of crystal-scale anisotropy on effective ice stiffness, with regional-scale consequences on ice dynamics. Using the flexural response of Priestley Glacier to tidal forcing as an experimental framework, we constrain isotropic and anisotropic elastic models of vertical tidal ice-shelf flexure. We find that a five-fold reduction of local ice stiffness within narrow lateral shear-zone best fits DInSAR measurements from Sentinel-1. Our modeling not only reproduces 31 double-differential interferograms but also resolves them into 56 individual maps of vertical displacement during SAR image acquisition. Validated with GPS measurements, the inclusion of effective shear-zone weakening significantly reduces the root-mean-square-error of predicted and observed vertical displacement by 84%, from 0.182 m to 0.03 m. These results highlight the untapped potential of DInSAR imagery for mapping ice anisotropy along the feature-rich Antarctic grounding zone, an essential parameter for advancing current ice-sheet flow models.