Abstract Understanding the coastal zone of the Antarctic Ice Sheet (AIS), where it interacts with the Southern Ocean and warmer air masses, is crucial for predicting Antarctica's influence on the global climate and sea level. This region has multiple tipping mechanisms that could trigger large, rapid, and potentially irreversible changes in the AIS, the Southern Ocean and their global connections in the coming centuries. The AIS remains the largest source of uncertainty in future sea‐level projections. Bed topography beneath the ice shelves and the coastal ice sheet is not yet well documented, and is a major source of this uncertainty. This review assesses current knowledge of the coastal zone and highlights methods to investigate it, including aerogeophysical surveys, ground‐ and ship‐based measurements, satellite observations, and computer modeling. An ensemble analysis of published bed topography data sets identifies significant data gaps and their regional distribution, framed in the context of current ice‐sheet behavior and potential instability. We propose scientific priorities and guidelines for future aerogeophysical surveys, advocating for a comprehensive, coordinated international effort to build a next‐generation data set of Antarctic bed properties. Such an initiative would significantly advance understanding of the role of coastal processes in ice‐sheet dynamics, reducing uncertainties in sea‐level rise projections and improving predictions of future ocean and climate changes.

Cenozoic plate divergence across the West Antarctic Rift System, important for understanding the role of Pacific plate motion in generating the prominent similar to 47 Ma bend in the Hawaii-Emperor seamount chain, is inferred and calculated using model estimates of relative motions between the plates of eastern and western Antarctica and their neighbours. Problematically, basin-fill and melt products that might confirm inferred pre-bend divergence are unknown, whilst calculations of post-bend motion have come to infer much of the rift system in the deep Antarctic interior was a collision zone. This work presents updated plate kinematic models based on improved satellite altimeter data that combine, within estimated confidence and at high temporal resolution, to replicate the extent of subglacial extensional rift basins in West Antarctica and the mid-Eocene (similar to 45 Ma) maximum ages of Cenozoic magmatic rocks associated with them. Consistent with the absence of older rift-related rocks, the new models do not recapitulate their predecessors' inferences of a Paleocene onset or phase of intra-Antarctic divergence, but may instead offer a context to diverse lines of evidence for pre-Eocene plate convergence within Zealandia. Without Paleocene divergence in Antarctica, absolute motion of the Pacific plate can be expected to have changed little at the time of the Hawaii-Emperor bend, as implied by the uneventful Pacific-Antarctic relative motion path derived from the new models. Future work on the causes of the bend should therefore focus on processes responsible for migration of the Hawaii hotspot relative to the Pacific mantle.

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.

The Pernambuco Plateau Basin (PPB) of northeastern Brazil contains an important record of continental rifting at the boundary between the major South Atlantic basins and the Equatorial Atlantic Gateway (EAG). The geology and structure of the PPB are described using high-quality long-offset multi-channel seismic data. The deep seismic imaging reported here shows that the PPB is not thick continental crust with a thin sediment veneer, but thinned continental crust with half-graben with sediment thicknesses in excess of 3 km. Within these deep graben we find large halokinetic structures in the form of salt diapirs and pillows that root into the early synrift. Submarine volcanic edifices are also clearly imaged, the oldest of which have bases close to the synrift-to-post-rift transition. We discuss the evolution of the PPB integrating the implications of the newly observed evidence for synrift salt deposition and early post-rift submarine volcanic activity as well as a re-analysis of recent plate models. The proposed best-fit model has PPB rifting in the Aptian and early Albian, with final break-up relatively late in the Albian.

The ice sheets of the Antarctic continent are supported and stabilised by floating ice shelves. Any future decrease in ice shelf mass and stability is expected to increase ice sheet drainage thus potentially contributing to a rise in the global sea level. Basal melting is a critical factor concerning ice shelf stability. Its rates are strongly dependent on the bathymetry underneath the ice shelves, as this directly influences sub-ice water circulation and its interactions with the open ocean. Therefore, accurate knowledge of sub-ice bathymetry is crucial to estimate the exchange of water masses and heat with the open ocean. We have created a model of the seafloor topography beneath the Evans Ice Stream - draining into the Ronne Ice Shelf, one of the world’s largest ice shelves - by the inversion of legacy airborne gravity data constrained by seismic and ice-penetrating radar depth references. The new bathymetric model is a distinct improvement over existing topographic compilations based on interpolated depths, providing a range of new information on topographic characteristics beneath the ice shelf with increased resolution and detail. The model shows a deep, asymmetric and U-shaped trough beneath the Evans Ice Stream that follows the ice stream’s flow direction. The bathymetry shows that the retrograde slope of the seafloor on the continental shelf and beneath the outer Ronne Ice Shelf continues as far as the ice stream’s grounding line. Should warm water masses from the open ocean cross the continental shelf edge, this slope would permit intrusion of these water masses all the way up to the grounding line. The new bathymetric model thus enables a step towards being able to more confidentially estimate basal melt rates beneath the Evans Ice Stream and their effect on ice shelf and ice sheet stability. The depth and shape of the seabed beneath numerous other ice shelves and areas of permanent sea ice coverage around the Antarctic margins remains poorly constrained or completely unknown. As well as the Evans cavity model, new data and plans for upcoming bathymetric modelling of some of these other areas are highlighted.

Cretaceous to earliest Oligocene plate motions between Greenland and North America are only modellable at high resolution from a short-lived (61-42 Ma) sequence of magnetic isochrons in the Labrador Sea. Understanding them at other times is hampered by interpretational conflicts and low resolution in geoscientific observations of the Labrador Sea, Davis Strait, Baffin Bay, and Eurekan Orogen. To better contextualize these observations, we build and manipulate models of North America-Eurasia and Eurasia-Greenland divergence in order to depict post-84 Ma North American-Greenland motions at quantified high resolution. Among our findings, we show that the North American-Eurasian plate boundary propagated northwards, leading the continental shelves in the Labrador Sea to separate by 74-72 Ma and in Baffin Bay later, at around 63 Ma, and that field evidence for the Eurekan Orogeny having occurred in two distinct phases is directly related to a 46 Ma change in Greenland-North American plate motion parameters.

Models depicting the plate kinematic development of the Indian Ocean have a range of applications including in paleogeographic studies and in formulating and testing ideas about plume/plate interactions. Until now, these applications have been forced to tolerate egregious model/observation inconsistencies concerning the relative motion history of India and Madagascar. Whilst the Phanerozoic record of these motions begins with ∼90 Ma basalts that erupted along a narrow rift basin, all modern plate kinematic models for the Indian Ocean predict hundreds of kilometres of relative motions, in diverse and conflicting senses, over several tens of millions of years prior to the eruptions. The diversity of these predicted motions suggests they are artefacts that arise from differing approaches taken to modelling the development of the eastern and western parts of the ocean, rather than a reflection of insufficient or absent geological observations. In this contribution, I present a new model for the early plate kinematic development of the Indian Ocean that is constrained by observational evidence for relative plate motion azimuths in the Enderby and western Bay of Bengal basins and by explicitly maintaining a rigid mid- and early Cretaceous Indo-Malagasy body. This approach requires the model to feature two small tectonic plates between the continental margins of eastern India and East Antarctica. The older of the two, Mandara, is an intraoceanic plate in the Enderby Basin that may have formed in relation to delivery of excess melt from the Kerguelen plume to the basin's mid-ocean ridge. The younger plate, Vasuki, in the western Bay of Bengal Basin, also accommodated plume-related melt at its boundaries, in its case from the Marion and possibly also the Crozet plume. The model shows this plate transporting Sri Lanka ∼800 km southwards along the eastern Indian continental margin to its present location. The model also requires the presence of around half a million square kilometres of continental crust beneath the Kerguelen Plateau, which lies within the range of published observation-led estimates of its extent. Neither the absence of evidence for relative motions between India and Madagascar prior to ∼90 Ma, nor the modelled Euler rotation pole's location afterwards, are consistent with suggestions that traction forces related to the ascent of the Marion plume drove the mid-Cretaceous onset of subduction in the western Neotethys.

A new continent-wide aeromagnetic anomaly compilation for Antarctica, conformed at longer wavelengths with SWARM satellite magnetic data includes recent international datasets collected after the ADMAP 2.0 compilation analysed within the 3D Earth project of ESA. This ADMAP 2.0+ product includes: 1) ROSETTA data collected by a US-NZ team over the Ross Ice Shelf; 2) reprocessed US-German and UK data collected over the Amundsen Sea Embayment; 3) German, Danish, UK- Argentina-Norwegian data over the Recovery ice stream catchment; 4) ESA PolarGAP data over South Pole and 5) enhanced vintage datasets for the Gamburtsev Subglacial Mountains and Wilkes and Dome C regions in East Antarctica. A new digital database was assembled using updated line data holdings and all data were levelled. microlevelled and stitched together via grid stitching approaches and subsequently differentially continued to 4 km and re-gridded on a 4 km grid mesh. Here we use this new aeromagnetic anomaly compilation to re-assess Antarctic geothermal heat flux (GHF) heterogeneity, a critical basal boundary condition that influences Antarctic ice sheet flow and subglacial melting patterns and hydrology, and is related to crustal and lithospheric structure, composition, and heat production. Within the 4D Antarctica ESA project we applied Curie Depth Point (CDP) estimation using the centroid, modified centroid and fractal/defractal approaches. Our new CDP map reveals regions of enhanced GHF along the coast of the Amundsen Sea Embayment, in agreement with independent seismological estimates. Potential thermal anomalies within the West Antarctic Rift System (WARS) also underlie the Byrd Subglacial Basin. Linear rift related anomalies are now imaged more clearly beneath the Siple Coast ice streams and active subglacial lake districts. In East Antarctica, the new CDP estimates over the enigmatic WSB are significantly deeper compared even to the coldest sectors of the WARS. This suggests that if Mesozoic to Cenozoic extension affected this region, it mostly occurred at upper crustal levels rather than the whole lithosphere, in general agreement with relatively sparse seismological evidence for a predominantly cratonic lithospheric environment. A particularly intriguing region of enhanced GHF is identified in Dronning Maud Land. We propose that this could arise from lithospheric thinning perhaps associated with delamination processes, which have been independently inferred from petrological signatures in post-orogenic granitoids, emplaced after the pan-African age assembly of Gondwana. Alternatively, this feature could reflect thermal anomalies related to much later passive margin formation during Gondwana rifting and break up. Finally, we discuss intriguing GHF anomalies inferred in the Dome C and Dome A subglacial lake regions in interior East Antarctica. We suggest the hypothesis that these anomalies relate to anomalously high intracrustal heat production, such as observed in Australia in some Proterozoic terranes, or to ill-constrained reactivation of the inherited structural architecture, This includes major Proterozoic and younger Pan-African age orogenic belts that may have been reactivated in response to far field stresses during Mesozoic to Cenozoic Gondwana break up and subsequent sea floor spreading processes.

Science, without effective dissemination, has a very short life and little impact. Yet, most scientific research is hidden away behind exclusive and expensive paywalls imposed by traditional publishers. Tektonika is an Earth Science community-led diamond open-access journal (DOAJ: free for authors, free for readers) publishing peer reviewed research in tectonics and structural geology. It is a grass-roots initiative driven by the enthusiasm and devotion of a wide and diverse spectrum of Earth Scientists from around the globe, intended to help shape a new landscape for publishing in the geosciences. Since its launch at EGU2022, Tektonika has been growing steadily thanks to a constant stream of new manuscript submissions, many of which have already been published as part of the journal’s first two issues (the first compiled in July 2023, and the second in January 2024). In order to meet the increasing demands of running a growing journal, the original team of editors was expanded in 2023 (from 6 to 8 Executive editors, and from 13 to 21 Associate Editors). Despite initial external skepticism, our experience over the last few years mirrors those of our sister journals, proving that community-driven DOAJs can not only succeed but thrive. The community support has been palpable throughout - from those submitting their work for publication, to others helping us reach a wider audience through social media, to the many that volunteer their time to support the editorial work, the review process, and the typesetting and pagination of the accepted research papers.

The Wilkes Subglacial Basin (WSB) continues to attract significant international attention as a potential area of substantial East Antarctic Ice Sheet (EAIS) retreat. Determining whether this sector of East Antarctica was indeed a major contributor to past global sea level rise and whether it will be again in the future beyond 2100, remains a key priority for new interdisciplinary research.Aerogeophysical exploration has unveiled that the bedrock dips inland and is grounded up to 2.1 km below sea level (bsl) within its remarkably deep sub-basins and remains at a depth 500 km inland of the present-day grounding zone.Despite a growing body of knowledge, geological, geomorphological, and oceanographic evidence for the location, amount and rate of EAIS ice sheet retreat within the WSB remains incomplete and in parts controversial, and numerical model predictions for retreat during past warmer periods (e.g. the mid-Pliocene, mid-Miocene and even more recent Quaternary times) also differ significantly.Here we review some of the results from different existing aerogeophysical campaigns and data compilations in the WSB to discuss the importance of also considering the heterogeneity in basal boundary conditions affecting and modulating EAIS behaviour, such as bed topography, geology, subglacial hydrology and geothermal heat flux, and also present several interpretations for past changes, including their associated uncertainties, unresolved issues and outstanding questions.We conclude by presenting our case for major new international aerogephysical exploration efforts such as in our newly proposed ICEOLIA ERC initiative to:1) provide key missing bathymetric and geological data coverage over the much less well surveyed continental shelf and ice shelf cavities, which is critical to study ice sheet-ocean interactions and to link marine geological/geophysical and drilling observations with the dynamics of the EAIS;2) glean an improved understanding of past processes and tipping points and finally3) help investigate 4D (i.e. both space and time dependent) Solid Earth influences on past, present and future ice sheet behaviour in this key sector of East Antarctica.

In dynamic gravimetry, i.e. airborne and shipborne gravimetry, levelling methods are used to refine gravity disturbance results based on neighbouring trajectories. In the traditional crossover adjustment, line biases are estimated using gravity disturbance residuals at trajectory line crossings as input to a least-squares adjustment. In an alternative method, the results along the complete trajectory are used to estimate the gravity disturbance field in the survey area and line biases in a one-step least-squares adjustment applying spherical radial basis functions. This makes the bias estimation more robust since the observations are not restricted to a small number of residuals at crossings strongly affected by random errors. Adjustment becomes applicable to a wider range of campaigns including irregular trajectories without many crossings. Within the scope of this work, existing methods that estimate line biases are extended to bias estimation based on trajectory segments with inter-bias interpolation. The extended method can be particularly useful for irregular trajectories without a sufficient number of line crossings. The introduced levelling methods are evaluated at the example of three airborne campaigns: a fixed wing survey at Germany with a very dense grid, a fixed wing survey in East Antarctica with varying line separation, and a helicopter survey on Svalbard with highly irregular trajectories. It is shown that the levelling method based on spherical radial basis functions improves the precision in all evaluated campaigns, even when a traditional crossover levelling is not possible.

Airborne gravimetry is an important technique for gravity field determination and sub-surface interpretations in geophysics and exploration. Traditionally, stable platform gravimeters were used, which maintained the gravity sensor's alignment with the local vertical. Recent advancements resulted in an increased utilisation of strapdown gravimeters. This study compares the performance of a GT-2A stable platform gravimeter and an iMAR iNAVRQH-1003 strapdown gravimeter, which were operated simultaneously in an airborne campaign at East Antarctica. Furthermore, novel combination approaches for the individual gravimeter solutions are presented and assessed. The strapdown gravimeter demonstrated superior overall precision (1.71 mGal without crossover adjustment, 1 mGal = 10-5 m/s2), lower high-frequency noise and lower line-to-line biases compared to the GT2A (2.40 mGal) but was susceptible to significant flight-to-flight biases. However, the elimination of these flight biases is possible through the estimation of a single bias per flight via crossover adjustment. Moreover, the benefits of strapdown technology, including reduced space, weight, and operational requirements, contribute to the growing preference for strapdown over stable platform gravimeters. All combination approaches yielded improved solutions compared to the single gravimeter results, despite the different noise levels of the single gravimeter results. After crossover adjustment, a precision of 1.0 mGal was obtained. This highlights the potential for enhanced gravity field determination when using two or more high-precision gravimeters, provided that their frequency-dependent noise characteristics are considered appropriately.

Topography and physical conditions at the base of the Antarctic ice sheet are critical inputs for studies of its present and future ice discharge, and of subglacial geology and hydrology. Airborne gravity and magnetic data, especially when interpreted jointly can help us to link the geology from outcrops towards the coastal areas to unknown subglacial regions further inland. Here we use airborne geophysical data obtained during the joint AWI-BGR campaign WEGAS/GEA between 2015 and 2017 in central Dronning Maud Land (DML) as input for a novel joint inversion scheme. With regard to Gondwana reconstruction, this region is critical because it hosts the ice-covered Forster Magnetic Anomaly, a prominent lineament crossing central DML for some 100s of kilometers south of the main mountain chain. This lineament, originally interpreted as the main pan-African suture of East and West Gondwana, likely represents the eastern margin of Kalahari and its boundary to the Tonian Oceanic Arc Super Terrane (TOAST). In the inversion using the software jif3D, sources of the gravity and magnetic field are combined through a coupling method which decreases the variation of information (VI), so data misfit and model dissimilarity are minimized simultaneously. The model results can be classified in geologically meaningful provinces by applying cluster analysis based on machine learning. Our joint inversion approach improves previous interpretations and sheds light on the crustal architecture of the study area, contributing to further studies on the interaction between the ice sheet and the underlying solid earth.

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.

Magnetic data collection in Antarctica is commonly carried out using airborne platforms, which allow to cover large spatial areas. Airborne surveys in Antarctica have been conducted since the 1950s as part of international and collaborative efforts. A challenge in creating a homogenous magnetic data compilation for Antarctica arises from heterogeneity in data collection through the decades, for example from different flight lines spacing, different observation height and long time period between surveys. Traditional data processing is performed manually or semi-automated which is time consuming due to the factors described above.Equivalent source technique is a powerful tool to automate the data processing to combine irregular airborne surveys on different observation heights and time periods. The magnetic field data from different airborne surveys can be represented by a set of equivalent sources that accurately reproduce the input data. The magnetic forward response of the equivalent sources can be calculated at any height making upward / downward continuation obsolete and allowing a uniform observation height between surveys. Furthermore, the magnetic field can be calculated on a regular grid, removing irregular flight lines from airborne data compilations. Combining the equivalent source method with despiking-, wavelet filtering-, IGRF/DGRF correction- and weighted distance base station correction routines allow a fully automated processing workflow to create a harmonised magnetic compilation containing irregular airborne surveys with decreased noise.We present a test case in East Antarctica to highlight the potential of an automated processing workflow to harmonise magnetic airborne data without biases arising from manual processing. Here, we utilise ICECAP data (2009-2017) and RAE data (1956-1960) as well as the ADMAP data compilation grid as prior. The next step is to use ADMAP line data to create a fully automated homogeneous continent wide Antarctic magnetic data compilation under the SCAR ADMAP working group umbrella.

Antarctic geothermal heat flux (GHF) is poorly known restricting our ability to assess its influence on subglacial hydrology and ice sheet dynamics. Within the 4D Antarctica and the 3D Earth ESA projects, a new Antarctic aeromagnetic anomaly compilation, conformed at long wavelengths with SWARM satellite magnetic data was complied. All the datasets were levelled, microlevelled and stitched together. We also differentially continued all survey data to 4 km and re-gridded the compilation onto a 4 km grid mesh.Our new aeromagnetic anomaly compilation enables us to re-assess Antarctic geothermal heat flux (GHF) heterogeneity, a critical basal boundary condition that influences Antarctic ice sheet flow and subglacial melting and hydrology. To estimate GHF we applied Curie Depth Point (CDP) estimation using the centroid, modified centroid and fractal/defractal approaches. We compared our CDP results with independent constraints on crustal and lithosphere thickness derived from seismological, airborne gravity and satellite gravity modelling and effective elastic thickness estimates. We also considered empirical estimates of GHF derived from seismology and recent models of intracrustal heat production from gravity inversion to assess additional uncertainties associated with CDP to GHF conversion. We performed both automated continental scale estimates and nested manual analysis of CDP and GHF with a specific focus on different Antarctic subglacial lake districts.We found elevated GHF in the West Antarctic Rift System (WARS) beneath the rapidly changing Thwaites (THW) and Pine Island sectors of the West Antarctic Ice Sheet (WAIS) and along the edge of the Marie Byrd Land block. Focussed estimates of GHF were performed over the cascading active lakes beneath THW to provide new constraints for hydrological modelling in this critical sector of the WAIS. We image a large degree of heterogeneity in thermal basal boundary conditions beneath the active subglacial lake districts that underlie the ice streams flowing into the Ross Sea Embayment, which we relate to hitherto poorly known tectono-magmatic segmentation of the WARS.In East Antarctica, elevated GHF is associated with some of the active lakes underlying the Byrd glacier catchment, but relatively lower GHF values are typical of both the active and static lakes of the northern Wilkes Subglacial Basin (WSB). This suggests limited upper crustal extension beneath this enigmatic subglacial basin compared to major Mesozoic to Cenozoic extension in the WARS. These findings agree with current seismological evidence for well-preserved fast and cold craton margin lithosphere beneath most of the WSB.We image relatively elevated GHF beneath the Dome C and Dome A subglacial lake districts. This may be caused by cryptic but large-scale provinces of high heat producing Precambrian basement or could reflect major intraplate reactivation of Precambrian fault systems. Elevated GHF is also imaged in Dronning Maud Land and stretching from Enderby Land to Princess Elizabeth Land. We propose that this could reflect Cambrian age lithosphere thinning due to orogenic collapse processes that affected major and yet still cryptic paths of Gondwana-forming orogenic belts fringing East Antarctica. Additionally, Jurassic to Cretaceous thinning was likely superimposed and associated with passive margin formation during Gondwana break-up.

Antarctica poses a unique challenge for data compilation and sharing, due to the sourcing of data from many national programs and a diversity of surveys and data access protocols. Coordinated by the Scientific Committee on Antarctic Research, the Antarctic Digital Magnetic Anomaly Project (ADMAP) has made huge progress to collate coordinate and disseminate the magnetic data of Antarctica. ADMAP’s first iteration was produced in 2001, and the second iteration was released in 2018. The community is looking now towards the next iteration to support ongoing research in Antarctica. We present here a roadmap for this data compilation, with a focus on the ability for researchers to access a live and interactive resource, to add new data when it is available, and for this to be realised in the compilation soon after data submission. For this it is necessary to ease the burden of data processing, to define a consistent approach to the data handling, and to accelerate the timeline from data-submission to incorporation into the compilation. The approach therefore is founded on an automated data-processing workflow that can accommodate the wide variety of data submitted (variable spacings, heights and times of collection), can tolerate incremental updates to the main product within a reasonable compute load, and can achieve results within a reasonable tolerance without requiring manual intervention. This presentation focuses on the intended approach to compilation and the expected outcomes, based on a test-case.

Knowledge of the bathymetry of Antarctica’s margins is crucial for models and interpretations of ice-ocean interactions and their influence on ongoing and future sea level change, but remains patchy where ice shelves and multi-year sea ice block measurements. Here, we present a bathymetric model for the central Dronning Maud Land margin, based on a constrained inversion of airborne gravity data. It shows the cavities beneath the region’s two ice shelves to be much deeper than in existing bathymetric compilations, but to be shielded from Warm Deep Water ingress and basal melting by the presence of shallow bathymetric sills along the continental shelf. Over areas of multi-year sea ice, the model returns bathymetric estimates of similar accuracy to gravity interpolation-based methods over open water. Airborne gravity thus presents an opportunity to bathymetrically map hundreds of thousands of square kilometres of the most inaccessible margins of Antarctica at resolutions adequate for regional and global oceanographic and glaciological modelling and interpretation.

The Oldest Ice Reconnaissance (OIR) airborne geophysical survey in East Antarctica was flown over approximately 170,000 km2 of the Dome Fuji region in 2016/17. The survey's results support new insights into the subglacial geology and its meaning for the tectonic histories of the supercontinents Rodinia and Gondwana. The new magnetic and radar-derived bed topography data are integrated with previously acquired magnetic and gravity data, allowing the mapping of crustal domains within and beyond the survey's limits. The magnetic data reveal three distinct domains within the survey region, delineated by N-S oriented boundaries, partly aligned with gravity domains following upward continuation transformations for both datasets. Additionally, four primary sets of magnetic lineaments were identified, exhibiting correlations with topographic and gravity patterns. These correlations indicate the continuation of the Tonian Oceanic Arc Super Terrane (TOAST) southward of its previously known southern limit. Moreover, an E-W-trending magnetic anomaly, the Elbert magnetic anomaly, suggests the suture between the recently-proposed subglacial Valkyrie craton and the TOAST. Furthermore, the analysis reveals a broad scale shear zone, named here the OIR shear zone, which formed as a result of oblique collision of the Ruker and Valkyrie cratons during the amalgamation of Gondwana.