Determining basal boundary conditions fo r assessments of East Antarctic ice sheet evolution and stability in the Wilkes Subglacial Basin

• Main Authors: Ferraccioli, F, Young, D, Blankenship, D, Jordan, T, Bozzo, E, Siegert, M., ARMADILLO, EGIDIO, BALBI, PIETRO
• Other Authors: Armadillo, Egidio, Balbi, Pietro
• Format: Conference Object
• Language: English
• Published: 2014
• Subjects: Antarctic; East Antarctica; East Antarctic Ice Sheet; Wilkes Subglacial Basin; Usi; Antarc*; Antarctica; Ice Sheet
• Online Access: http://hdl.handle.net/11567/856335

The Wilkes Subglacial Basin (WSB) extends for ca 1,400 km into the interior of East Antarctica and hosts several major glaciers that drain a large sector of the East Antarctic Ice Sheet (EAIS). The region is of major significance for assessing t he stability of the EAIS, as it lies well below sea level and its bedrock deepens inland, making it potentially more prone to marine ice sheet instability. It has become a focus of research within IODP Leg 318 that aims to better comprehend the initial stages of glaciation and the hist ory and longer term stability of the EAIS. Understanding geological boundary conditions onshore is important to assess their influence on ice sheet dynamics and interpret the paleo-ice s heet record. Early geophysical models inferred a major extensional sedimentary basin beneath t he WSB that could potentially help maintain enhanced glacial flow and may be linked to inferred but strongly controversial Neogene deglaciation in the region. Later geophysical models proposed that the WSB is a Cenozoic flexural basin with little or no Cenozoic infill. A joint Italian-UK aerogeophysical exploration campaign is super-seeding these earlier geophysical vi ews of the WSB (Ferraccioli et al., 2009, Tectonophysics ): i) Precambrian and Paleozoic basement faults can be recognised as providing structural controls on the topographic margins of the basin and it deep sub-basins; ii) the crust beneath the basin is thinner compared to the Tran santarctic Mountains, but is unlikely to be strongly affected by Cretaceous or Cenozoic rifting (Jordan et al., 2013, Tectonophysics ), iii) its bedrock is composed of ro cks of different ages and compositi on, including Proterozoic basement, Neoproterozoic and Cambrian sediments intruded by Cambrian arc rocks and cover rocks formed primarily by Beacon sediments intru ded by Jurassic Ferrar sills. A new collaborative Italian-US and UK initiative is underway to analyse and model the variable geological boundary conditions in the WSB usi ng previous and new geophysical ...