Antarctic Sedimentary Basins and Their Influence on Ice‐Sheet Dynamics

Abstract

Knowledge of Antarctica’s sedimentary basins builds our understanding of the coupled evolution of tectonics, ice, ocean, and climate. Sedimentary basins have properties distinct from basement‐dominated regions that impact ice‐sheet dynamics, potentially influencing future ice‐sheet change. Despite their importance, our knowledge of Antarctic sedimentary basins is restricted. Remoteness, the harsh environment, the overlying ice sheet, ice shelves and sea ice all make fieldwork challenging. Nonetheless, in the past decade the geophysics community has made great progress in internationally coordinated data collection and compilation with parallel advances in data processing and analysis supporting a new insight into Antarctica’s subglacial environment. Here, we summarize recent progress in understanding Antarctica’s sedimentary basins. We review advances in the technical capability of radar, potential fields, seismic and electromagnetic techniques to detect and characterize basins beneath ice and advances in integrated multi‐data interpretation including machine‐learning approaches. These new capabilities permit a continent‐wide mapping of Antarctica’s sedimentary basins and their characteristics, aiding definition of the tectonic development of the continent. Crucially, Antarctica’s sedimentary basins interact with the overlying ice sheet through dynamic feedbacks that have the potential to contribute to rapid ice‐sheet change. Looking ahead, future research directions include techniques to increase data coverage within logistical constraints, and resolving major knowledge gaps, including insufficient sampling of the ice‐sheet bed and poor definition of subglacial basin structure and stratigraphy. Translating the knowledge of sedimentary basin processes into ice‐sheet modelling studies is critical to underpin better capacity to predict future change.

Sediment Freeze‐On and Transport Near the Onset of a Fast‐Flowing Glacier in East Antarctica

“…Considering measured particle concentrations in Antarctic ice within the range of ∼1%–20% (Christoffersen et al., 2010; Gow et al., 1979; Winter et al., 2019), we estimate a sediment volume of at least 1.8 km 3 within our study area (assuming the lower particle concentration boundary of 1%). This inference points toward the likely availability of a substantial amount of loose sediment within source regions where particles are embedded in the basal ice, which is supported by the potential location of sedimentary basins in the upstream region (Aitken et al., 2023).…”

“…In the southern region, freeze-on may exist, but the accreted ice might not exhibit strong dielectric contrasts due to the lack of sediment for the entrainment process. However, this would contradict the location of sedimentary basins (Aitken et al, 2023) and findings where pure frozen ice at the base in other locations was documented (MacGregor et al, 2009). Still, sediment availability might also relate to the varying degrees of past erosion between the southern and northern survey region leading to the hypothesis that unconsolidated sediment has been removed by past glacial flow in the southern region.…”

Geology Matters for Antarctic Geothermal Heat

“…Li and Aitken (2024) use gravity inversion, coupled with seismic observations and interpolations of crustal thickness, to derive density variations in the lithosphere. Their analysis incorporates predictions of subglacial sedimentary basins (Aitken et al, 2023;Li et al, 2022) to yield a geologically coherent model of crustal structure. They then apply an empirical relation to link upper crustal density to map the distribution of crustal heat production with a resolution of 40 km.…”