Crustal architecture of the Wilkes Subglacial Basin in East Antarctica, as revealed from airborne gravity data

Jordan, Tom A.; Ferraccioli, Fausto; Armadillo, Egidio; Bozzo, E.

doi:10.1016/j.tecto.2012.06.041

Cited by 50 publications

(97 citation statements)

References 58 publications

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“…The Parker‐Oldenberg algorithms, estimate the gravitational effects of topography using LaFehr ' s [] curvature correction with intermediate zones (one to eight grid cells from the gravity station) calculated using the flat‐topped square prism approach [ Nagy , ], and the far zone (>8 grid cells from the gravity station) terrain effect calculated using the annular ring segment approximation of [ Kane , ]. Incorporating airborne radar data from the ICECAP, WLK, and WISE‐ISODYN surveys, the 3‐D gravitational effect of the ice sheet and bed topography was calculated at an altitude of 3950 m using average ice and bedrock densities of 0.92 g/cm 3 and 2.67 g/cm 3 [ Studinger et al ., ; Filina et al ., ; Jordan et al ., ], respectively. Subtracting these calculated gravity effects from the free‐air anomaly yielded the full terrain‐corrected Bouguer gravity results gridded and displayed in Figure with similar resolution and gridding techniques used for free‐air gravity results.…”

Section: Geophysical Analysis and Modelingmentioning

confidence: 99%

“…[], and Jordan et al . [] have suggested structural control as opposed to the historic Stern and ten Brink [] hypothesis of flexure to explain the TAM and WSB topography.…”

Section: Geophysical Analysis and Modelingmentioning

confidence: 99%

“…[], and Jordan et al . [], a locally compensated forward isostatic model with no inherent lateral strength [ Watts , ] was confirmed to model 3‐D variability of crustal thickness and the associated gravitational trend across the WSB with greater accuracy. Hence, an Airy isostatic 3‐D regional structural digital elevation model [ Jachens and Griscom , ] of the Moho surface was combined with ICECAP/IceBridge, WISE‐ISODYN, and WLK airborne survey data and assigned ice, crust, and mantle densities of 0.92, 2.8, and 3.3 g/cm 3 , respectively, to calculate the isostatic residual gravity anomaly using Geosoft's Oasis montaj® software (Figure ).…”

Section: Geophysical Analysis and Modelingmentioning

confidence: 99%

“…To evaluate subglacial sedimentary basin boundaries, area, volume, and potential depositional controls, we integrate over 110,867 line kilometers of aerogeophysical data collected as part of NASA's IceBridge program and the University of Texas‐Austin Institute for Geophysics (UTIG) ICECAP (Investigating the Cryospheric Evolution of the Central Antarctic Plate) program across four austral field seasons between 2008 and 2013, combined with historical WSB aerogeophysical data flown during the WISE (Wilkes basin/Transantarctic Mountains System Exploration)‐ISODYN (Ice‐house Earth: Stability or DYNamism?) campaign of 2005–2006 [ Ferraccioli et al ., ; Jordan et al ., ] and the WLK (Wilkes Land Transect) campaign of 1999–2000 [ Studinger et al ., ; Carter et al ., ].…”

Section: Introductionmentioning

confidence: 99%

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Distribution of subglacial sediments across the Wilkes Subglacial Basin, East Antarctica

et al. 2016

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Topography, sediment distribution, and heat flux are all key boundary conditions governing the dynamics of the East Antarctic Ice Sheet (EAIS). EAIS stability is most at risk in Wilkes Land across vast expanses of marine-based catchments including the 1400 km × 600 km expanse of the Wilkes Subglacial Basin (WSB) region. Data from a recent regional aerogeophysical survey (Investigating the Cryospheric Evolution of the Central Antarctic Plate (ICECAP)/IceBridge) are combined with two historical surveys (Wilkes basin/Transantarctic Mountains System Exploration-Ice-house Earth: Stability or DYNamism? (WISE-ISODYN) and Wilkes Land Transect (WLK)) to improve our understanding of the vast subglacial sedimentary basins impacting WSB ice flow and geomorphology across geologic time. Analyzing a combination of gravity, magnetic and ice-penetrating radar data, we present the first detailed subglacial sedimentary basin model for the WSB that defines distinct northern and southern subbasin isopachs with average sedimentary basin thicknesses of 1144 m ± 179 m and 1623 m ± 254 m, respectively. Notably, more substantial southern subbasin sedimentary deposition in the WSB interior supports a regional Wilkes Land hypothesis that basin-scale ice flow and associated glacial erosion is dictated by tectonic basement structure and the inherited geomorphology of preglacial fluvial networks. Orbital, temperate/polythermal glacial cycles emanating from adjacent alpine highlands during the early Miocene to late Oligocene likely preserved critical paleoclimatic data in subglacial sedimentary strata. Substantially thinner northern WSB subglacial sedimentary deposits are generally restricted to fault-controlled, channelized basins leading to prominent outlet glacier catchments suggesting a more dynamic EAIS during the Pliocene.

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Section: Geophysical Analysis and Modelingmentioning

confidence: 99%

“…[], and Jordan et al . [] have suggested structural control as opposed to the historic Stern and ten Brink [] hypothesis of flexure to explain the TAM and WSB topography.…”

Section: Geophysical Analysis and Modelingmentioning

confidence: 99%

Section: Geophysical Analysis and Modelingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Distribution of subglacial sediments across the Wilkes Subglacial Basin, East Antarctica

et al. 2016

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“…While the pattern of this topography is presumably tectonic in origin (Rose, 1979;Studinger et al, 2001;Jordan, Ferraccioli, Armadillo, & Bozzo, 2013), the current over-deepened geometry of the troughs is also attributed here to fluvial and glacial modification during more restricted paleo ice sheet configurations (e.g., in Oligocene and Miocene times; Young et al, 2011). As deforming sediments at the base of ice sheets can alter frictional stress and modify ice flow speeds (Bell et al, 1998;Peters et al, 2006;Stokes, 2018) it is important to assess the possibility of marine sediments at the base of Patuxent Trough, Foundation Trough, and the Offset Rift Basin. Three subglacial troughs provide a series of lowelevation conduits that channelize ice flow from interior Antarctica to Foundation Ice Stream and ice streams of the Siple Coast.…”

Section: Subglacial Topographymentioning

confidence: 99%

Topographic Steering of Enhanced Ice Flow at the Bottleneck Between East and West Antarctica

Winter

Ross

Ferraccioli

et al. 2018

Geophysical Research Letters

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Hypothesized drawdown of the East Antarctic Ice Sheet through the “bottleneck” zone between East and West Antarctica would have significant impacts for a large proportion of the Antarctic Ice Sheet. Earth observation satellite orbits and a sparseness of radio echo sounding data have restricted investigations of basal boundary controls on ice flow in this region until now. New airborne radio echo sounding surveys reveal complex topography of high relief beneath the southernmost Weddell/Ross ice divide, with three subglacial troughs connecting interior Antarctica to the Foundation and Patuxent Ice Streams and Siple Coast ice streams. These troughs route enhanced ice flow through the interior of Antarctica but limit potential drawdown of the East Antarctic Ice Sheet through the bottleneck zone. In a thinning or retreating scenario, these topographically controlled corridors of enhanced flow could however drive ice divide migration and increase mass discharge from interior West Antarctica to the Southern Ocean.

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The subglacial geology of Wilkes Land, East Antarctica

Aitken

Young

Ferraccioli

et al. 2014

Geophysical Research Letters

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148

222

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Wilkes Land is a key region for studying the configuration of Gondwana and for appreciating the role of tectonic boundary conditions on East Antarctic Ice Sheet (EAIS) behavior. Despite this importance, it remains one of the largest regions on Earth where we lack a basic knowledge of geology. New magnetic, gravity, and subglacial topography data allow the region's first comprehensive geological interpretation. We map lithospheric domains and their bounding faults, including the suture between Indo-Antarctica and Australo-Antarctica. Furthermore, we image subglacial sedimentary basins, including the Aurora and Knox Subglacial Basins and the previously unknown Sabrina Subglacial Basin. Commonality of structure in magnetic, gravity, and topography data suggest that pre-EAIS tectonic features are a primary control on subglacial topography. The preservation of this relationship after glaciation suggests that these tectonic features provide topographic and basal boundary conditions that have strongly influenced the structure and evolution of the EAIS.

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Crustal architecture of the Wilkes Subglacial Basin in East Antarctica, as revealed from airborne gravity data

Cited by 50 publications

References 58 publications

Distribution of subglacial sediments across the Wilkes Subglacial Basin, East Antarctica

Distribution of subglacial sediments across the Wilkes Subglacial Basin, East Antarctica

Topographic Steering of Enhanced Ice Flow at the Bottleneck Between East and West Antarctica

The subglacial geology of Wilkes Land, East Antarctica

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