Hypothesis for mega-outburst flooding from a palaeo-subglacial lake beneath the East Antarctic Ice Sheet

Jordan, Tom A.; Ferraccioli, Fausto; Corr, Hugh; Graham, Alastair G C; Armadillo, Egidio; Bozzo, E.

doi:10.1111/j.1365-3121.2010.00944.x

Cited by 24 publications

(34 citation statements)

References 49 publications

(71 reference statements)

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“…A statistical analysis of bed roughness has previously been used as a means of quantifying information about subglacial landforms obtained from RES studies [ Rippin et al , 2006; Bingham et al , 2007; Bingham and Siegert , 2009; Jordan et al , 2010]. The method uses a Fourier analysis of the bed topography to produce a parameter with a single value for each point in the survey.…”

Section: Methodsmentioning

confidence: 99%

Evidence of a hydrological connection between the ice divide and ice sheet margin in the Aurora Subglacial Basin, East Antarctica

et al. 2012

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Subglacial hydrology in East Antarctica is poorly understood, yet may be critical to the manner in which ice flows. Data from a new regional airborne geophysical survey (ICECAP) have transformed our understanding of the topography and glaciology associated with the 287,000 km2 Aurora Subglacial Basin in East Antarctica. Using these data, in conjunction with numerical ice sheet modeling, we present a suite of analyses that demonstrate the potential of the 1000 km‐long basin as a route for subglacial water drainage from the ice sheet interior to the ice sheet margin. We present results from our analysis of basal topography, bed roughness and radar power reflectance and from our modeling of ice sheet flow and basal ice temperatures. Although no clear‐cut subglacial lakes are found within the Aurora Basin itself, dozens of lake‐like reflectors are observed that, in conjunction with other results reported here, support the hypothesis that the basin acts as a pathway allowing discharge from subglacial lakes near the Dome C ice divide to reach the coast via the Totten Glacier.

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Section: Methodsmentioning

confidence: 99%

Evidence of a hydrological connection between the ice divide and ice sheet margin in the Aurora Subglacial Basin, East Antarctica

et al. 2012

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“…The widespread and accelerating retreat of Pine Island and Thwaites glaciers constitutes a potential threat to the stability of the West Antarctic Ice Sheet (WAIS) (Rignot et al, 2008(Rignot et al, , 2014Joughin et al, 2014;Feldmann and Levermann, 2015;Shepherd et al, 2018;Yu et al, 2018). The routing, storage, and expulsion of subglacial water from beneath the WAIS directly influences its mass-loss rates and, accordingly, sealevel rise (Joughin et al, 2002;Alley et al, 2006;Bell et al, 2007;Stearns et al, 2008). Variability in subglacial water supply can lead to ice-sheet instability (Schoof, 2010).…”

Section: Introductionmentioning

confidence: 99%

Past water flow beneath Pine Island and Thwaites glaciers, West Antarctica

et al. 2019

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Outburst floods from subglacial lakes beneath the Antarctic Ice Sheet modulate ice-flow velocities over periods of months to years. Although subglacial lake drainage events have been observed from satellite-altimetric data, little is known about their role in the long-term evolution of ice-sheet basal hydrology. Here, we systematically map and model past water flow through an extensive area containing over 1000 subglacial channels and 19 former lake basins exposed on over 19 000 km 2 of seafloor by the retreat of Pine Island and Thwaites glaciers, West Antarctica. At 507 m wide and 43 m deep on average, the channels offshore of presentday Pine Island and Thwaites glaciers are approximately twice as deep, 3 times as wide, and cover an area over 400 times larger than the terrestrial meltwater channels comprising the Labyrinth in the Antarctic Dry Valleys. The channels incised into bedrock offshore of contemporary Pine Island and Thwaites glaciers would have been capable of accommodating discharges of up to 8.8 × 10 6 m 3 s −1 . We suggest that the channels were formed by episodic discharges from subglacial lakes trapped during ice-sheet advance and retreat over multiple glacial periods. Our results document the widespread influence of episodic subglacial drainage events during past glacial periods, in particular beneath large ice streams similar to those that continue to dominate contemporary ice-sheet discharge.

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“…Pine Island Glacier Bingham et al (2017) Wilkes Subglacial Basin Jordan et al (2010) Carlson Inlet King (2011) Rutford Ice Stream King et al (2016) Various locations in Antarctica Shi et al (2010) To create the training dataset, we use a sliding window to obtain square tiles cropped from the high resolution (250 m) groundtruth bed elevation grids, with each tile required to be completely filled with data (i.e. no NaN values).…”

Section: Location Citationmentioning

confidence: 99%

DeepBedMap: Using a deep neural network to better resolve the bed topography of Antarctica

Leong¹,

Horgan²

2020

Preprint

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Abstract. To better resolve the bed elevation of Antarctica, we present DeepBedMap – a novel machine learning method that produces realistic Antarctic bed topography from multiple remote sensing data inputs. Our super-resolution deep convolutional neural network model is trained on scattered regions in Antarctica where high resolution (250 m) groundtruth bed elevation grids are available. The model is then used to generate high resolution bed topography in less well surveyed areas. DeepBedMap improves on previous interpolation methods by not restricting itself to a low spatial resolution (1000 m) BEDMAP2 raster image as its prior. It takes in additional high spatial resolution datasets, such as ice surface elevation, velocity and snow accumulation to better inform the bed topography even in the absence of ice-thickness data from direct ice-penetrating radar surveys. Our DeepBedMap model is based on an adapted Enhanced Super Resolution Generative Adversarial Network architecture, chosen to minimize per-pixel elevation errors while producing realistic topography. The final product is a four times upsampled (250 m) bed elevation model of Antarctica that can be used by glaciologists interested in the subglacial terrain, and by ice sheet modellers wanting to run catchment or continent-scale ice sheet model simulations. We show that DeepBedMap offers a more realistic topographic roughness profile compared to a standard bicubic interpolated BEDMAP2 and BedMachine Antarctica, and envision it to be used where a high resolution bed elevation model is required.

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Hypothesis for mega-outburst flooding from a palaeo-subglacial lake beneath the East Antarctic Ice Sheet

Cited by 24 publications

References 49 publications

Evidence of a hydrological connection between the ice divide and ice sheet margin in the Aurora Subglacial Basin, East Antarctica

Evidence of a hydrological connection between the ice divide and ice sheet margin in the Aurora Subglacial Basin, East Antarctica

Past water flow beneath Pine Island and Thwaites glaciers, West Antarctica

DeepBedMap: Using a deep neural network to better resolve the bed topography of Antarctica

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