SEMINAR: Ice and water in East Antarctica � what role does tectonics play?

The flow of ice sheets, and their susceptibility to change, is significantly influenced by a series of non-linear interactions between the ice and the materials beneath - water and rocks. Water, in various ways, exerts an accelerative influence on ice sheet flow. Freshwater lubricates the ice sheet bed, relatively warm seawater can melt the base of floating ice, and can intrude under the ice sheet, causing dramatic collapse.

Rocks provide many influences: hard crystalline bedrock rock provides a dry, cold, rough surface that often inhibits fast flow; sedimentary rocks are softer, and provide more favourable hydrology for large-scale flow. Either can involve high-heat flux which promotes basal melting. Large-scale tectonics provides the topographic template on which all of these influences act. East Antarctica contains Earth’s largest ice sheet, and recent research suggests greater vulnerability to change than previously thought. Understanding the EAIS and its controlling processes, is critical to estimating long term change. And yet it remains one of the largest regions on Earth where we have lacked a basic knowledge of geology.

New magnetic, gravity and subglacial topography data from the 2008-2013 ICECAP program allow a comprehensive geological interpretation of the Wilkes Land region. This interpretation leads to key insights into the configuration of Gondwana, Rodinia and Columbia. Furthermore, we image subglacial sedimentary basins, including the Wilkes, Aurora and Knox Subglacial Basins, and define the previously unknown Sabrina Subglacial Basin. These tectonic features are a primary control on topographic and basal boundary conditions, including the hydrology network, that have strongly influenced the structure and evolution of the EAIS, both in its inception and early dynamic stages, and also during its existence as a “stable” continent-scale ice sheet.

Biography:

Alan Aitken completed his undergraduate studies in Geophysical Sciences at Lancaster University (UK) and an MSc in Geophysics at the University of Otago (NZ). In 2005 Alan came to Australia to embark upon a PhD at Monash University.

Since completing his PhD in 2009 Alan has been employed as a lecturer at Monash University (2009 – 2010) and subsequently at The University of Western Australia (2011 – present) where he took up the Goodeve Lectureship in July 2011.

Alan's research is in the application of magnetic and gravity methods to understanding tectonic systems.

PS* This seminar is free and open to the public & no RSVP required.

****All Welcome****