Jo Whittaker, BSc (Hons)/BCom MSc

PhD Candidate

Geosciences Demountables, Room 141
Phone: +61 2 9036 6538
Fax: +61 2 9036 6588
Email:

Supervisor
A/Prof Dietmar Müller

PhD title: "Reconstruction of plate movements in and around the Indian Ocean"

I am currently undertaking my PhD under the supervision of Dietmar Müller on various aspects of tectonic plate movements in and around the Indian Ocean, and aim to submit my thesis in March 2008. The working title of my thesis is “Reconstruction of plate movements in and around the Indian Ocean”. I am also a member of the EarthByte Group which aims to integrate interoperability between plate tectonic data and geodynamic computer modelling (www.earthbyte.org).

I am currently conducting research in two main areas: (1) the origins of seafloor roughness, and (2) the rifting history of Australia and Antarctica.

Seafloor Roughness

I am currently focussing on the origins of seafloor roughness, which is a poorly understood parameter fundamental to controlling the circulation and mixing of heat in the ocean (Polzin, et al., 1997) and dissipating eddy kinetic energy (Gille, et al., 2000). I wish to understand the global relationship between the gravity roughness of ridge flank topography, and the rates, asymmetry and obliquity, relative to the regional strike of the MOR, of oceanic crustal accretion. To do this I am using a global analysis of marine gravity anomalies from satellite altimetry, downward continued to the seafloor (Smith, 1998).

I aim to derive a predictive framework for seafloor roughness, which will hopefully facilitate an improved understanding of mid-ocean ridge processes as well as the causes of roughness. Such a framework could also be used to predict topography with a given roughness on subducted ocean floor to derive paleobathymetric maps, where conjugate ridge flanks are still preserved. Such models could be used as input for ocean circulation models leading to more accurate ocean circulation calculations through geological time.

Australian-Antarctic Rifting

A zone of transitional crust, up to 120 km in width, separates continental and oceanic crust on the Southern Australian and East Antarctic conjugate margins. Offshore southern Western Australia the transition zone is composed of the very rough E-W oriented ridges of the Diamantina Zone, while further east the crust changes to be composed of rough tilted basement blocks. A matching pattern exists in the conjugate Antarctic transition zone. The different types of transitional crust formed during a period of oblique northwest-southeast relative Australian-Antarctic plate motion that occurred until 50 Ma, ~30 million years longer than previously thought (Whittaker et al., 2007).

The complex margin morphology of the Australian-Antarctic margins is similar to that found on the well-studied Iberia-Newfoundland margins and a number of different rift models have been proposed for both rift systems. Utilizing a variety of geological and geophysical parameters I am examining the numerous proposed rift models in order to unravel the early rifting and spreading history of the Australian-Antarctic margins.

• Whittaker, J. M., Müller, R.D., Leitchenkov, G., Stagg, H., Sdrolias, M., Gaina, C. and Goncharov, A. 2007, Major Australian-Antarctic Plate Reorganisation at Hawaiian-Emperor Bend Time, Science, 318. (Abstract, Full Text)
• Henrys SA, Wilson TJ, Whittaker JM, Fielding CR, Hall JM, Naish T. 2007. Tectonic History of mid-Miocene to present, southern Victoria Land Basin, inferred from seismic stratigraphy, in McMurdo Sound, Antarctica. In: Cooper AK, Raymond C.R. et al., editors. Antarctica: A Keystone in a Changing World? Online Proceedings of the 10th ISAES: USGS Open-File Report 2007-1047, Short Research Paper 049.
• Whittaker, J., Müller, R.D., Sdrolias, M. and Heine, C., 2007, Sunda-Java trench kinematics, slab window formation and overriding plate deformation since the Cretaceous, Earth and Planetary Science Letters. 255, 445-457, doi:10.1016/j.epsl.2006.12.031 (pdf)
• Whittaker, J. and Müller, R.D., 2006, Seismic Stratigraphy of the Adare Trough Area, Antarctica, Marine Geology, 230, 179-197 (pdf)

• Whittaker, J., Müller, R.D., Sdrolias, M., and Heine, C., 2007. Relationships between plate tectonics, slab windows, stress regimes and heat flow in Indonesia from 80 Ma to the present. Emerging Plays in Australasia, Geological Society, London 17-19th July, 2007
• Whittaker, J., and Müller, R.D., 2007. New Australia-Antarctica reconstruction model dramatically alters reconstructed rift basin geometry. Emerging Plays in Australasia, Geological Society, London 17-19th July, 2007
• Whittaker, J., Müller, R.D., Sdrolias, M., Heine, C., 2006, Connecting oceanic palaeo age-grids with Sunda Trench kinematics, slab window formation and overriding plate deformation since the Cretaceous EGU General Assembly Vienna (AUT) - Geophys. Res. Abstracts 8, EGU06-A-03251.
• Whittaker, J., Müller, R.D., Sdrolias, M., Heine, C., 2006, Connecting oceanic palaeo age-grids with Sunda Trench kinematics, slab window formation and overriding plate deformation since the Cretaceous, American Association of Petroleum Geologists, International Conference and Exhibition, Perth, 5-8 Nov. 2006, Australia, Abstract 106134.
• Whittaker, J. and Müller, R.D., New 1-minute satellite altimetry reveals major Australian-Antarctic plate reorganisation at Hawaiian-Emperor bend time, Eos Trans AGU, 87(52), Fall Meet. Suppl., Abstract T51F-08.
• Whittaker, J., Müller, R.D., Sdrolias, M., and Heine, C., 2006, Connecting oceanic palaeo-age grids with Sunda trench kinematics, slab window formation and overriding plate deformation since the Cretaceous, EGU General Assembly: Vienna, Austria
• Whittaker, J., Henrys, S., Wilson, T., Lawver, L., Barrett, P., and Naish, T., 2004, Seismic Stratigraphy of the Terror Rift, Southern McMurdo Sound, Antarctica, AGU Fall Meeting: San Francsico, POSTER.