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A quantitative understanding of how sediment discharge from subglacial fluvial systems varies in response to glaciohydrological conditions is essential for understanding marine systems around Greenland and Antarctica and for interpreting sedimentary records of cryosphere evolution. Here we develop a graph based approach, GraphSSeT, to model subglacial fluvial sedimentary transport using subglacial hydrology model outputs as forcing. GraphSSeT includes glacial erosion of bedrock and a dynamic sediment model with exchange between the active transport system and a basal sediment layer. Sediment transport considers transport-limited and supply-limited regimes and includes stochastically-evolving grain size, network scale flow management and tracking of detrital provenance. GraphSSeT satisfies volume balance and sediment velocity and transport capacity constraints on flow. GraphSSeT is demonstrated for synthetic scenarios that probe the impact of variations in hydrological, geological and glaciological characteristics on sediment transport over multi-diurnal to seasonal timeframes. For steady-state hydrology scenarios on seasonal timescales we find a primary control from the scale and organisation of the channelised hydrological flow network. The development of grain size dependant selective transport is identified as the major secondary control. Non-steady-state hydrology is tested on multi-diurnal timescales, for which sediment discharge scales with peak water input leading to increased sediment discharge compared to steady state. With increasing application of subglacial hydrology models, GraphSSeT extends this capacity to define quantitatively the volume, grain size distribution and detrital characteristics of sediment discharge, and enables a stronger connection of models of the glacio-hydrological system with constraints from the sediment record and impacts on marine systems. [ABSTRACT FROM AUTHOR]

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High‐quality aeromagnetic data are important in guiding new knowledge of the solid earth in frontier regions, such as Antarctica, where these data are often among the first data collected. The difficulties of data collection in remote regions often lead to less than ideal data collection, leading to data that are sparse and four‐dimensional in nature. Standard aeromagnetic data collection procedures are optimized for the (nearly) 2‐D data that are collected in industry standard surveys. In this work we define and apply a robust magnetic data correction approach that is optimized to these four‐dimensional data. Data are corrected in three phases, with phase 1 operations on point data, correcting for spatiotemporal geomagnetic conditions, then phase 2 operations on line data, adjusting for elevation differences along and between lines and in phase 3, a line‐based leveling approach to bring lines into agreement while preserving data integrity. For a large‐scale East Antarctic survey, the overall median cross‐tie error reduction error reduction is 93%, reaching a final median error of 5 nT. Error reduction is spread evenly between phases 1 and 3. Phase 2 does not reduce error directly but permits a stronger error reduction in phase 3. Residual errors are attributed to limitations in the ability to model 4‐D geomagnetic conditions and also some limitations of the inversion process used in phase 2. Data have improved utility for geological interpretation and modeling, in particular quantitative approaches, which are enabled with less bias and more confidence. Plain Language Summary: Observations of the Earth's magnetic field underpin our knowledge of geology and tectonics and are often among the first data collected in frontier regions. This work focuses on the problems experienced in remote surveys, including observation periods extending over years, and flying heights that vary over kilometers. Conventional approaches are designed for more tightly constrained survey collection and can be inappropriate for these data. A new way to process airborne observations of magnetic field intensity is developed and tested. Applied to a data set in East Antarctica, the data quality is substantially improved and the data better reveals the geology hidden beneath the ice of Antarctica. Key Points: A new approach to correcting four‐dimensional aeromagnetic data is developed and tested with the large‐scale ICECAP data set from East AntarcticaSubstantial improvements in data quality and reliability are seen and error thresholds are well definedThese improvements in data quality support the investigation of subglacial geology and tectonics in magnetic data [ABSTRACT FROM AUTHOR]

East Antarctica remains one of the few continental regions on Earth where an understanding of the origin and causal processes responsible for topographic relief is largely missing. Low‐temperature thermochronology studies of exposed Precambrian basement revealed discrete episodes of cooling and denudation during the Paleozoic–Mesozoic; however, the significance of these thermal events and their relationship to topography across the continental interior remains unclear. Here we use zircon and apatite (U‐Th)/He thermochronology to resolve the low‐temperature thermal evolution of a poorly exposed section of East Antarctic basement in the Bunger Hills region and gain insights into the chronology and style of landscape evolution across East Antarctica. Thermal history modeling results indicate that Precambrian basement in the Bunger Hills region experienced a distinct cooling episode during the Late Paleozoic–Triassic, which we relate to ~2–4 km of regional exhumation associated with intracontinental rifting, followed by a second episode of localized cooling and ≤1 km exhumation during the Late Jurassic–Cretaceous separation of India from East Gondwana. These findings, combined with existing thermochronological and tectonic evidence, support a continent‐scale denudation event associated with uplift and exhumation of large sections of Precambrian basement during Late Paleozoic–Triassic Pangea‐wide intracontinental extension. By contrast, continental extension associated with the Jurassic–Cretaceous breakup of East Gondwana resulted in significant denudation only locally in regions west of the Bunger Hills. We propose that the combined effects of these Paleozoic–Mesozoic tectonic events had a profound impact on the topography across the East Antarctic interior and influenced the long‐term landscape evolution of East Antarctica. Key Points: First low‐temperature thermochronology (LTT) study of the Bunger Hills basement in East AntarcticaLTT data record widespread cooling and exhumation of East Antarctic basement associated with Pangea‐wide extensionLarge‐scale topographic framework established during intracontinental extension has influenced long‐term landscape evolution of East Antarctica [ABSTRACT FROM AUTHOR]

The subglacial landscape of Princess Elizabeth Land (PEL) in East Antarctica is poorly known due to a paucity of ice thickness measurements. This is problematic given its importance for understanding ice sheet dynamics and landscape and climate evolution. To address this issue, we describe the topography beneath the ice sheet by assuming that ice surface expressions in satellite imagery relate to large-scale subglacial features. We find evidence that a large, previously undiscovered subglacial drainage network is hidden beneath the ice sheet in PEL. We interpret a discrete feature that is 140 × 20 km in plan form, and multiple narrow sinuous features that extend over a distance of ~1100 km. We hypothesize that these are tectonically controlled and relate to a large subglacial basin containing a deep-water lake in the interior of PEL linked to a series of long, deep canyons. The presence of 1-km-deep canyons is confirmed at a few localities by radio-echo sounding data, and drainage analysis suggests that these canyons will direct subglacial meltwater to the coast between the Vestfold Hills and the West Ice Shelf. [ABSTRACT FROM AUTHOR]