A probabilistic and model-based approach to the assessment of glacial detritus from ice sheet change

Aitken, Alan; Urosevic, L.

doi:10.1016/j.palaeo.2020.110053

Cited by 8 publications

(7 citation statements)

References 57 publications

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“…In particular, sedimentation rates at the Vanderford Glacier were twice those at the Totten Glacier during the mid-late Oligocene (27 to 24 Ma), when global temperatures were approximately 3 to 4 • C higher than the present day (Westerhold et al, 2020). Furthermore, modelling indicates similar levels of erosion potential for the bed under both the Totten and Vanderford glaciers -and indeed, that these glaciers have the highest erosive potential in East Antarctica -such that similar magnitudes of sediment discharge from each of these two glaciers are possible under present-day ice sheet geometries (Aitken and Urosevic, 2021).…”

Section: Introductionmentioning

confidence: 91%

Assessing the potential for ice flow piracy between the Totten and Vanderford glaciers, East Antarctica

McCormack,

Roberts,

Kulessa

et al. 2023

The Cryosphere

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Abstract. The largest regional drivers of current surface elevation increases in the Antarctic Ice Sheet are associated with ice flow reconfiguration in previously active ice streams, highlighting the important role of ice dynamics in mass balance calculations. Here, we investigate controls on the evolution of the flow configuration of the Vanderford and Totten glaciers – key outlet glaciers of the Aurora Subglacial Basin (ASB) – the most rapidly thinning region of the East Antarctic Ice Sheet (EAIS). We synthesise factors that influence the ice flow in this region and use an ice sheet model to investigate the sensitivity of the catchment divide location to changes in surface elevation due to thinning at the Vanderford Glacier (VG) associated with ongoing retreat and thickening at the Totten Glacier (TG) associated with an intensification of the east–west snowfall gradient. The present-day catchment divide between the Totten and Vanderford glaciers is not constrained by the geology or topography but is determined by the large-scale ice sheet geometry and its long-term evolution in response to climate forcing. Furthermore, the catchment divide migrates under relatively small changes in surface elevation, leading to ice flow and basal water piracy from the Totten to the Vanderford Glacier. Our findings show that ice flow reconfigurations occur not only in regions of West Antarctica like the Siple Coast but also in the east, motivating further investigations of past, and the potential for future, ice flow reconfigurations around the whole Antarctic coastline. Modelling of ice flow and basal water piracy may require coupled ice sheet thermomechanical and subglacial hydrology models constrained by field observations of subglacial conditions. Our results have implications for ice sheet mass budget studies that integrate over catchments and the validity of the zero flow assumption when selecting sites for ice core records of past climate.

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Section: Introductionmentioning

confidence: 91%

Assessing the potential for ice flow piracy between the Totten and Vanderford glaciers, East Antarctica

McCormack,

Roberts,

Kulessa

et al. 2023

The Cryosphere

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“…Bedrock tracers such as isotopic data are important fingerprints of glacial erosion that can be reliably recovered from sediment cores (Licht and Hemming, 2017). Quantitative model-based approaches using these data can constrain cryopshere processes more reliably, but transport is a source of ambiguity in the detrital provenance problem (Aitken and Urosevic, 2021).…”

Section: Detrital Provenance Trackingmentioning

confidence: 99%

“…As a consequence, the composition of detritus reflects variations in transport rather than supply. This suggests that, for correct representation of the detrital signatures of glaciers and ice sheets it is important to understand the transport as well as erosion (Aitken and Urosevic, 2021). Our input model scenarios have everywhere the same basal velocity, have no topography, and no variation in bed roughness or bedrock erosive properties.…”

Section: Glaciological Controls On Sediment Fluxmentioning

confidence: 99%

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Aitken

2024

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“…Most of Antarctica (>99%) is concealed beneath ice and snow, and there are very few direct estimates of heat transfer from ice sheet boreholes (Burton‐Johnson et al., 2020; Stål et al., 2022). Extrapolation of Antarctic geology from sparse marginal outcrops (e.g., Cox et al., 2023; Sanchez et al., 2021) into the subglacial regions is largely based on geophysical interpretations, linked where possible with geological observations of ice‐transported moraines and marine sediment (Aitken et al., 2014; Aitken & Urosevic, 2021; Goodge, 2018; Goodge et al., 2017; Kodama et al., 2024; Mulder et al., 2019; Stål et al., 2020). Entirely cryptic terranes, not constrained by direct geological observations, are likely in the subglacial interior (e.g., Aitken et al., 2014; Ferraccioli et al., 2011; Fitzsimons, 2000; Goodge & Finn, 2010; Hasterok et al., 2022; Stål et al., 2019).…”

Section: Urgency and Controversy Of Antarctic Geothermal Heatmentioning

confidence: 99%

Geology Matters for Antarctic Geothermal Heat

Stål,

Halpin,

Goodge

et al. 2024

Geophysical Research Letters

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Geothermal heat plays a vital role in Antarctic ice sheet stability. The continental geothermal heat flow distribution depends on lithospheric composition and ongoing tectonism. Heat‐producing elements are unevenly enriched in the crust over deep time by various geological processes. The contribution of crustal heat production to geothermal heat flow is widely recognized; however, in Antarctica, crustal geology is largely hidden, and its complexity has frequently been excluded in thermal studies due to limited observations and oversimplified assumptions. Li and Aitken (2024), https://doi.org/10.1029/2023GL106201 take a significant step forward, focusing on Antarctic crustal radiogenic heat. Utilizing gravity inversion and rock composition data, they show that the crustal heterogeneity introduces considerable variability to heat flow. However, modeling crustal heat production proves challenging because it lacks distinct associations with geophysical observables and has a narrow spatial association. Robust quantification of geothermal heat production and heat flow must incorporate explicit aspects of geology.

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A probabilistic and model-based approach to the assessment of glacial detritus from ice sheet change

Cited by 8 publications

References 57 publications

Assessing the potential for ice flow piracy between the Totten and Vanderford glaciers, East Antarctica

Assessing the potential for ice flow piracy between the Totten and Vanderford glaciers, East Antarctica

Reply on RC2

Geology Matters for Antarctic Geothermal Heat

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