Safe navigation for Antarctic expeditions is critically challenged by harsh environmental conditions, particularly in areas with complex sea ice distributions. Ensuring secure routes between icebreakers and research stations is essential for successful supply transportations and field operations. In this study, we proposed an integrated technical framework for safe path planning in Prydz Bay, East Antarctica, based on satellite-borne and airborne remote sensing data. Using large-scale satellite imagery, we extracted and analyzed sea ice conditions, including the spatial distribution of landfast sea ice, icebergs, and bare rocks, as well as surface smoothness information. High-resolution autonomous aerial vehicle data collected at Zhongshan Station further supported the analysis of the melting characteristics and microtopography of landfast sea ice. These multisource observations were incorporated into a cost path analysis approach to determine optimal and safe routes across landfast sea ice areas, aiming to provide guarantees for icebreaker navigation, supply transportation, and sea ice surface activities. The results demonstrate that the proposed approach effectively supports route planning by providing detailed environmental assessments, thereby enhancing the safety and efficiency of Antarctic expeditions. This framework offers a valuable tool for icebreaker navigation between ships and stations in polar environments.

Lake 90°E in Antarctica encompasses an area of 2000 km2, ranking it the second largest subglacial lake identified in the country by area, following Vostok Subglacial Lake. In this study, the overlying ice thickness and lake elevation of Lake 90°E were determined using airborne radio-echo sounding across two survey lines, conducted by the International Collaborative Exploration of the Cryosphere by Airborne Profiling in Princess Elizabeth Land (ICECAP/PEL) campaign during the 32nd Chinese National Antarctic Research Expedition (CHINARE 32, 2015–2016), and the depth of lake water was inversed by coupling with synchronous airborne gravity data. The analysis revealed a 15-m elevation increase in the ice sheet surface from the southeast to the northwest, correlating with a gradient in ice thickness that progresses from thin in the southeast to thick in the northwest. The maximum water depth of Lake 90°E is estimated as 320 m along the central line, bifurcated by a topographic ridge into two zones of varying depths, with exceptionally shallow water at its periphery. Thermodynamic modeling using data from two points along the survey lines indicated that melt rates at the ice–water interface have consistently been low over the last 400,000 years, varying between 0.56–0.95 mm/yr and 2.70–3.41 mm/yr, balanced by either basal freezing to the south or downstream water loss, thereby maintaining a thermodynamically stable state. Satellite imagery and altimetry data analyses identified no significant changes in the outline or elevation of the ice surface over the past 20 years. This study presents novel insights into the physiography and thermodynamic state of Lake 90°E, establishing a foundation for future drilling initiatives.

We present Bedmap3, the latest suite of gridded products describing surface elevation, ice-thickness and the seafloor and subglacial bed elevation of the Antarctic south of 60 °S. Bedmap3 incorporates and adds to all post-1950s datasets previously used for Bedmap2, including 84 new aero-geophysical surveys by 15 data providers, an additional 52 million data points and 1.9 million line-kilometres of measurement. These efforts have filled notable gaps including in major mountain ranges and the deep interior of East Antarctica, along West Antarctic coastlines and on the Antarctic Peninsula. Our new Bedmap3/RINGS grounding line similarly consolidates multiple recent mappings into a single, spatially coherent feature. Combined with updated maps of surface topography, ice shelf thickness, rock outcrops and bathymetry, Bedmap3 reveals in much greater detail the subglacial landscape and distribution of Antarctica’s ice, providing new opportunities to interpret continental-scale landscape evolution and to model the past and future evolution of the Antarctic ice sheets.

In autumn 2023, comprehensive geophysical surveys were conducted in the experimental section of the Shestakovka River basin (Central Yakutia) to identify structural features of the near-surface part of the geological section, in particular permafrost rocks and talik zones. The work objectives included ground penetrating radar (GPR) studies and electrical resistivity survey. Drilling and well temperature logging data were used in the interpretation. The work is relevant due to the importance of studying the processes occurring in the cryolithic zone due to global climate change, and the novelty lies in clarifying the structure of the study area. The average permittivity of rocks across the section on the right and left banks of the river is 15.5 and 6.9, respectively. The differences are due to moisture saturation and the degree of soil freezing. The depth of the talik base on the right bank of the river is from 2 to 14 m with an average value of 6.1 m. On the left bank of the river, it varies from 3 to 7.1 m with an average value of 4.2 m. According to electrical exploration, the medium is a four-layer section. The upper layer about 2 m thick is the most heterogeneous in electrical resistivity and corresponds to seasonally frozen soils. The base of the underlying talik on the geoelectric section is traced at a depth of 4 to 7 m, which is consistent with drilling and GPR data. The third high-resistivity layer corresponds to permafrost rocks. The electrical resistivity in them increases by an order of magnitude compared to the talik zone and is about 2000 Ohmm against the background of 100-270 Ohmm. The underlying lower layer is characterized by a decrease in electrical resistivity to 220 Ohmm, which may be associated with a change in the lithological composition or with the groundwater circulation.

Unmanned aerial vehicle (UAV) has become an increasingly popular remote sensing platform in Antarctica. Due to the challenging natural conditions and lack of global navigation satellite system (GNSS) references in Antarctica, GNSS-supported direct georeferencing holds great potential for remote sensing applications in this region. Based on UAV surveys and GNSS observations we performed in Larsemann Hills, Antarctica, four GNSS-supported direct georeferencing schemes for UAV photogrammetry without ground control point (GCP) were designed and evaluated. Three of the schemes can generate high-accuracy photogrammetric products (horizontal accuracy: similar to 0.7 ground sampling distance (GSD), vertical accuracy: similar to 2.6 GSD). The fourth scheme, while exhibiting a lower accuracy at the meter-level, could offer high flexibility, and the accuracy of its derived products could be improved by post-flight transformation. The selection of an appropriate georeferencing scheme should be contingent upon the given application scenario, which can enhance the quality and accuracy of UAV photogrammetry in Antarctica. Potential applications of UAV remote sensing in Antarctica were discussed. It's proven that UAV photogrammetry constitutes a reliable tool for Antarctic expedition path planning and ice morphology evolution monitoring. Our study demonstrated that direct georeferencing can generate high-accuracy UAV products in a reliable and feasible way in Antarctica.

The paper presents a review of the studies carried out in the area of the subglacial Lake Vostok (East Antarctica) to date. They include geophysical, glaciological, geodesic, and geological investigations. The most important geophysical investigations were carried out by the Polar Marine Geosurvey Expedition. They included reflection and refraction seismic, and also radio-echo sounding. The major contribution to the study of this region was made by American researchers, who in the 2000/01 field season performed a complex airborne geophysical survey on a regular network. Their work included magnetometric, gravimetric, and radio-echo sounding measurements. All the research conducted found that the water surface area is 15 790 km², and its altitudinal height changes from –600 to –150 m. The average depth of Lake Vostok is 400 m, and the maximum marks reach 1 200 m. The water body volume is estimated at 6 100 km³. There are 11 islands in the lake, and their total area is 365 km². In addition, 56 isolated subglacial water bodies were found around the lake. A special section is devoted to a review of mathematical models of heat and mass transfer processes in the glacier and water movement in Lake Vostok.

Abstract. Radio-echo sounding (RES) has revealed an internal architecture within Antarctica’s ice sheets that records their depositional, deformational and melting histories. Crucially, spatially-widespread RES-imaged internal-reflecting horizons, tied to ice-core age-depth profiles, can be treated as isochrones that record the age-depth structure across the Antarctic ice sheets. These enable the reconstruction of past climate and ice-dynamical processes on large scales, which are complementary to but more spatially-extensive than commonly used proxy records across Antarctica. We review progress towards building a pan-Antarctic age-depth model from these data by first introducing the relevant RES datasets that have been acquired across Antarctica over the last six decades (focussing specifically on those that detected internal-reflecting horizons), and outlining the processing steps typically undertaken to visualise, trace and date (by intersection with ice cores, or modelling) the RES-imaged isochrones. We summarise the scientific applications to which Antarctica’s internal architecture has been applied to date and present a pathway to expanding Antarctic radiostratigraphy across the continent to provide a benchmark for a wider range of investigations: (1) Identification of optimal sites for retrieving new ice-core palaeoclimate records targeting different periods; (2) Reconstruction of surface mass balance on millennial or historical timescales; (3) Estimates of basal melting and geothermal heat flux from radiostratigraphy and comprehensively mapping basal-ice units, to complement inferences from other geophysical and geological methods; (4) Advancing knowledge of volcanic activity and fallout across Antarctica; (5) The refinement of numerical models that leverage radiostratigraphy to tune time-varying accumulation, basal melting and ice flow, firstly to reconstruct past behaviour, and then to reduce uncertainties in projecting future ice-sheet behaviour.

This study presents the results of mathematical modeling of the degree of effects of various characteristics on basal conditions in Antarctica. The model is based on the numerical solution of the one-dimensional Stefan problem. Five factors determining the nature of subglacial processes have been studied: ice thickness, snow-firn thickness, surface mass balance, air temperature, and geothermal heat flux. It was found that on the Antarctic plateau, slope, and coast, the geothermal heat flux has the greatest influence on the basal conditions. It is the heat flux that is responsible for the transition of most Antarctic lakes from a stable state to an active one (except for the ice stream regions). In areas where the ice sheet is thinner than 1,500 m, air temperature is the second most important factor affecting subglacial conditions. In areas where the glacier is thicker, the ice thickness begins to have a greater effect. The snow-firn thickness and snow accumulation have little effect on subglacial melt in most parts of Antarctica. Calculations over a 100-year period show that if meltwater accumulates on the bedrock rather than being completely channeled, it leads to a decrease in the average rate of subglacial melting by approximately 10 times.

Active subglacial lakes are capable of exchanging and transporting water through water flow paths, thus having an important impact on ice sheet movement and even on the regional mass balance. The use of satellite altimetry can indirectly reveal internal subglacial hydrological activity through direct surface elevation observation, which plays an important role in the study of the evolution of active subglacial lakes. This paper monitors and analyzes the activity of the subglacial lake Mercer (SLM) in the Whillans and Mercer Ice Stream (WIS/MIS), using data from the CryoSat-2 satellite radar altimetry and ICESat-2 satellite laser altimetry. We adopt the differential DEM model and the repeat orbit model based on their respective data characteristics. Finally, we reveal the temporal and spatial evolution patterns of SLM during 2011-2023, and construct the elevation anomaly time series. The results show that the central and western parts of SLM were the areas with more significant elevation anomalies, and there were three significant fill-drain cycles during the time periods studied in this research, with the elevation anomaly range reaching about 8 m and 4 m for the first and second cycles, respectively, and the lake is currently in the third significant draining phase. Furthermore, the elevation anomalies obtained during the mission overlap time of CryoSat-2 and ICESat-2 data are in good agreement, which confirms the accuracy of our method.

This study presents a mathematical model of heat and mass transfer for modelling the formation and evolution of taliks in the upper subsurface of the Larsemann Hills in East Antarctica. Four simulation scenarios were considered. The first one showed that thawed areas cannot form under snowfields. The second and third scenarios demonstrated the taliks did not form if the snow melted immediately after set the positive air temperatures and covered the surface 20 days before the set of negative air temperatures or immediately after that. According to the last scenario, talik forms when snow cover persists even with positive air temperature, and snow falls before the air temperature becomes negative. Modelling demonstrates that taliks in the Larsemann Hills exist, but they are mostly in an unstable state.

Basal melting of ice shelves has become one of the main causes of mass loss from the Greenland ice sheet. However, most studies have focused on individual ice shelves, making it difficult to gain a more comprehensive understanding of basal melting across Greenland ice shelves. To address this issue, we utilized timestamped ArcticDEM strip data coregistered with ICESat-2 data to estimate the basal melt rates of the ice shelves in North Greenland at a resolution of 150 m from 2013 to 2022, employing a mass conservation approach within the Lagrangian framework. Additionally, to investigate the influence of temperature on basal melt rates, a basic analysis correlating the basal melt rates with temperatures was conducted. Overall, the mass loss caused by basal melting of the six ice shelves has amounted to 27.86 +/- 35.63 Gt yr-1, accounting for approximately 90% of the non-calving mass loss, equivalent to a sea level rise of 0.08 +/- 0.10 mm yr-1, far exceeding surface mass loss and glacier calving. The two larger ice shelves, Petermann and 79 degrees North (79N), have contributed to 85% of the basal melt mass loss. Regarding the spatiotemporal distribution, the basal melt rates have gradually decreased from near the grounding line to the ice shelf front. Apart from the Ryder ice shelves, the basal melting of the other ice shelves is in a state of accelerated ablation. Moreover, compared to the skin temperature of the ice shelf, the sea water potential temperature has a greater impact on the basal melt rate.

One of the key components of this research has been the mapping of Antarctic bed topography and ice thickness parameters that are crucial for modelling ice flow and hence for predicting future ice loss and the ensuing sea level rise. Supported by the Scientific Committee on Antarctic Research (SCAR), the Bedmap3 Action Group aims not only to produce new gridded maps of ice thickness and bed topography for the international scientific community, but also to standardize and make available all the geophysical survey data points used in producing the Bedmap gridded products. Here, we document the survey data used in the latest iteration, Bedmap3, incorporating and adding to all of the datasets previously used for Bedmap1 and Bedmap2, including ice bed, surface and thickness point data from all Antarctic geophysical campaigns since the 1950s. More specifically, we describe the processes used to standardize and make these and future surveys and gridded datasets accessible under the Findable, Accessible, Interoperable, and Reusable (FAIR) data principles. With the goals of making the gridding process reproducible and allowing scientists to re-use the data freely for their own analysis, we introduce the new SCAR Bedmap Data Portal (https://bedmap.scar.org, last access: 1 March 2023) created to provide unprecedented open access to these important datasets through a web-map interface. We believe that this data release will be a valuable asset to Antarctic research and will greatly extend the life cycle of the data held within it. Data are available from the UK Polar Data Centre: https://data.bas.ac.uk (last access: 5 May 2023​​​​​​​). See the Data availability section for the complete list of datasets.

The study focuses on the current state of englacial Lake Dålk (Larsemann Hills Oasis), which was completely devastated in January 2017 by a catastrophic outburst and formed again in February 2020. A set of works including ground-penetrating radar (GPR) profiling, geodetic survey, core drilling, thermometric measurements and isotopic analysis was performed. As a result, new data were obtained about the modern boundaries of the reservoir, ice thickness and depths, as well as about the peculiarities of freezing of the lake after re-formation. Based on the field data obtained, one-dimensional mathematical modeling of Lake Dålk freezing was carried out, the results of which showed further scenarios of its evolution.

The urgency of creating a new complex typization of lakes of the East Antarctica oases is dictated not only by the desire to summarize accumulated Antarctic lakes’ data but also by the need to obtain the most informative characteristics of lake hydrological regime in the region for solving a wide applied problems’ range. Features of lake water level changes were used as a criterion in developing the complex typization of lakes of the East Antarctica oases for the first time, in contrast to existing classifications. The study was based on the analysis of literary and archive materials (the Larsemann Hills, the Schirmacher oasis, the Banger Hills, the Molodezhnyi oasis, the Vestfold Hills, and the McMurdo Dry Valleys), as well as our own expeditionary data (field seasons of 2017–2022, the Larsemann Hills). A group of indirect criteria (presence and type of natural dam, position in the cascade, flowage type, etc.) is proposed in addition to a group of direct criteria (duration of the lake filling phase, water level rise, etc. requiring organization of field observations) to obtain a holistic view of the water level regime of lakes. It is important that characteristics of the most indirect criteria can be obtained by visual reconnaissance surveys or by maps and remote sensing data. The identified 4 types (outbursting, tendentious, transit, and tidal) and 8 subtypes of lakes were illustrated by generalized graphs of water level changes, which objectively characterize the features of the lake hydrological regime. The openness of the typization suggests the opportunities for actualization with the accumulation of new scientific knowledge and data.

This article presents a numerical solution of the one-dimensional Stefan problem with two phase transitions, which is implemented on a non-uniform grid. The system of equations is written in a general form, i.e. it includes not only conductive, but also convective and dissipative terms. The problem is solved numerically by the front-fixing method on a non-uniform grid using an implicit finite-difference scheme, which is implemented by the sweep method. This algorithm can also be used to create more complex mathematical models of heat and mass transfer, as well as to describe glacial and subglacial processes. The mathematical apparatus proposed in the article was used to solve a specific problem of water freezing in a glacial crevasse. The presence and progression of crevasses, in turn, is a demonstrative factor indicating the dynamic activity of the glacier. Crevasses formed in one way or another can not only expand, but also decrease in size until they completely disappear. One of the reasons for their closure is the freezing of near-surface meltwater in the crevasse. Such a process was observed on glaciers near Mirny and Novolazarevskaya stations (East Antarctica). This process is modeled as an example of solving the Stefan problem. It is believed that all media are homogeneous and isotropic. The temperature of the water in the crevasse corresponds to the melting temperature of the ice. Modeling has shown that for the coastal part of the cold Antarctic glacier with an average temperature of –10°C and below, crevasses 5–10 cm of width freeze in less than a week. Wider ones freeze a little longer. 30 cm wide crevasses close in about two to three weeks, depending on the temperature of the glacier.

Reconstruction of glacial topography is important for assessing the ice dynamics of glaciers in the past and understanding how they may respond to climate change in the future. As an emerging strategy, unmanned aerial vehicles (UAVs) have been successfully used in glaciology applications to reconstruct surface topography and monitor the short-term dynamics of glaciers. However, none of these studies have focused on the ice dynamics of outlet glaciers in Antarctica. In this study, based on a combination of UAVs and a base station, we investigated Dalk Glacier, a typical marine-terminating glacier in East Antarctica, during two Chinese National Antarctic Research Expeditions from 2019 to 2020. By applying structure-from-motion and multi-view-stereo photogrammetry, high-resolution orthomosaics and digital elevation models of the glacial topography were reconstructed with centimeter-level accuracy via in situ validation, thus marking the first application of UAV observations in the monitoring of Antarctic outlet glaciers. Topographic evolution of the glacier was quantitatively analyzed from various aspects including ice velocity, surface elevation, crevasses, and ice front calving. A maximum ice velocity of ∼ 310 m a-1 at its terminus was observed, which was ∼ 90 m a-1 greater than that in satellite-based studies. We analyzed in detail the spatially heterogeneous changes in the ice velocity and surface elevation of the glacier under the influence of an ice rumple at its calving terminus. Combined with satellite images and existing datasets, we hypothesize that the large ice rumples at the glacier terminus could deform the glacier and potentially damage its structural integrity, thereby limiting the growth of its terminus.

Over the past 60 years, scientists have strived to understand the past, present and future of the Antarctic Ice Sheet. One of the key components of this research has been the mapping of Antarctic bed topography and ice thickness parameters that are crucial for modelling ice flow and hence for predicting future ice loss and ensuing sea level rise. Supported by the Scientific Committee on Antarctic Research (SCAR), the Bedmap3 Action Group aims not only to produce new gridded maps of ice thickness and bed topography for the international scientific community, but also to standardize and make available all the geophysical survey data points used in producing the Bedmap gridded products. Here, we document the survey data used in the latest iteration, Bedmap3, incorporating and adding to all of the datasets previously used for Bedmap1 and Bedmap2, including ice-bed, surface and thickness point data from all Antarctic geophysical campaigns since the 1950s. More specifically, we describe the processes used to standardize and make these and future survey and gridded datasets accessible under the ‘Findable, Accessible, Interoperable and Reusable’ (FAIR) data principles. With the goals to make the gridding process reproducible and to allow scientists to re-use the data freely for their own analysis, we introduce the new SCAR Bedmap Data Portal (bedmap.scar.org, last access: 18 October 2022) created to provide unprecedented open access to these important datasets, through a user-friendly webmap interface. We believe that this data release will be a valuable asset to Antarctic research and will greatly extend the life cycle of the data held within it. Data are available from the UK Polar Data Centre: https://data.bas.ac.uk.

Antarctica has been significantly influenced by global climate change. Owing to the spatiotemporal limitations of existing datasets, budgetary constraints, logistical challenges, and adverse temperature and climatic conditions of Antarctica, researchers face great challenges. Unmanned aerial vehicles (UAVs) have helped to solve this issue because they can collect high-resolution spatiotemporal data and conduct operations in inaccessible locations at a low cost and with ease compared with in situ observation and conventional spaceborne and airborne remote sensing. The development and testing of UAVs for use in polar environments mainly focus on enhancing UAV performance in extreme Antarctic conditions by improving their endurance, wind resistance, and aerial photography stability. The equipped multisensors, flexible data collection and operation window, and high-spatiotemporal resolution all contribute to making UAVs the most powerful platform for cryospheric research. In recent years, a series of UAV-related studies on the cryosphere have been published. However, a thorough review that explicitly details the scientific progress and possibilities of using UAVs in Antarctic polar research is lacking. In this era of rapid global and regional climate change, it is becoming increasingly necessary to employ UAVs to investigate the finer changes in the Antarctic ice sheet (AIS) and ice shelves. This work investigates the use of UAVs in the monitoring of the glacial microtopography (including rifts and crevasses, surface subsidence, and melting ponds), ice surface landforms, atmosphere, flora and fauna, sea ice, subglacial environment, and other aspects of Antarctic glaciology investigation, and it speculates on their future use in multidisciplinary research.

Abstract Lake Vostok, East Antarctica, represents an extensive water surface at the base of the ice sheet. Snow, ice and atmospheric pressure loads applied anywhere within the lake area produce a hydrostatic response, involving deformations of the ice surface, ice–water interface and particle horizons. A modelling scheme is developed to derive height changes of these surfaces for a given load pattern. It is applied to a series of load scenarios, and predictions based on load fields derived from a regional climate model are compared to observational datasets. Our results show that surface height changes due to snow-buildup anomalies are damped over the lake area, reducing the spatial standard deviation by one-third. The response to air pressure variations, in turn, adds surface height variability. Atmospheric pressure loads may produce height changes of up to $\pm$ 4 cm at daily resolution, but decay rapidly with integration time. The hydrostatic load response has no significant impact neither on ICESat laser campaign biases determined over the lake area nor on vertical particle movements derived from GNSS observations.

This study demonstrates the results of Russian airborne radio-echo sounding (RES) investigations and also seismic reflection soundings carried out in 1971–2020 over a vast area of coastal part of East Antarctica. It is the first comprehensive summary mapping of these data. Field research, equipment, errors of initial RES data, and methods of gridding are discussed. Ice thickness, ice base elevation, and bedrock topography are presented. The ice thickness across the research area varies from a few meters to 3620 m, and is greatest in the local subglacial depressions. The average thickness is about 1220 m. The total volume of the ice is about 710,500 km3. The bedrock heights vary from 2860 m below sea level in the ocean bathyal zone to 2040 m above sea level in the Grove Mountains area (4900 m relief). The main directions of the bedrock orographic forms are concentrated mostly in three intervals: 345∘–30∘, 45∘–70∘, and 70∘–100∘. The bottom melting rate was estimated on the basis of the simple Zotikov model. Total annual melting under the study area is about 0.633 cubic meters. The total annual melting in the study area is approximately 1.5 mm/yr.