Research topics within Earth Physics
Research into the structure and dynamics of the Earth uses a range of physical and mathematical techniques and is grouped into the three themes of Seismology and Mathematical Geophysics, Geophysical Fluid Dynamics, and Geodynamics. The work spans observational, theoretical, laboratory, computational and data oriented studies that are all directed to understanding the structure and physical processes in the solid and fluid Earth, and their environmental consequences.
Changes in mass are detected using space-gravity, which provides key information on how polar ice caps respond to temperature changes and how continental water resources vary. With climate warming, increased precipitation is predicted for low-latitude zones while regions such as southeastern Australia will become drier.
Seismology and Mathematical Geophysics employs wave propagation processes to study the nature of the Earth. Our research combines field observations, computer modelling, inversion and extensive data analysis to exploit the favourable location of Australia for seismic studies.
Sea level provides a key to understanding the climate system because it varies with the volume of the icecaps. Modelling historic sea levels helps to understand present and future variations. Evidence from coral terraces at Huon Penisula, Papua New Guinea, indicates that sea level rises of 9-16 m accompanied abrupt climate change during the period 30-65 ka. Satellite altimetry indicates a present-day ~3 mm/yr increase while tide gauge records suggest an acceleration in the 20th century.
The Geodynamics Group works on processes that deform Earth's lithosphere and the whole planet. The objective is to improve our understanding of the physical processes that act on and within the Earth through numerical modelling and observations.
Ocean circulation is driven by atmospheric winds, and by sinking of cold, dense water in the polar oceans. This circulation transports heat, chemicals, nutrients and salinity around the globe, and is an important part of the Earth's climate and ecosystem.
The amount and site of hydrogen in the upper mantle is important for understanding geochemical recycling of volatiles, and evolution of the mantle, atmosphere, and oceans. The entire water budget of the upper mantle may be accommodated at defect sites in nominally anhydrous minerals such as olivine and orthopyroxene.