2002 Annual Report - Earth Physics: Introduction
Research into the structure and dynamics of the Earth uses a range of
modern physical and mathematical techniques grouped into the three
broad areas of Geodynamics, Geophysical Fluid Dynamics and Seismology.
There are considerable interactions between these areas particularly
through common use of computational methods.
Work in Earth Physics spans observational, theoretical, computational
laboratory and data oriented studies that are all directed to
understanding the structure and processes in the solid and fluid
Earth and their environmental consequences.
The observational component in 2002 has been varied with geodetic
studies in Papua New Guinea, a detailed seismic experiment in southern
Victoria and Tasmania, and both geodetic and seismic deployments in
Antarctica (with some co-located sites). Laboratory work is mostly in
geophysical fluid dynamics and is frequently coupled to computational
studies as in studies of the fluctuations in the thermo-haline
circulation of the oceans.
Research in computational geophysics has taken many forms in 2002, with
studies of the evolution of mountain belts, development of techniques
for adaptive inversion of data sets and new models for the behaviour of
the mantle under early earth conditions.
Data oriented work has seen the development of new methods for surface
wave tomography with a consequent improvement of resolution of seismic
structure beneath the Australian region incorporating new data from western Australia.
Studies of the impact of glaciation and deglaciation have revealed
that the sea level changes in the period 100-75 Ma are more
complex than previously thought and as a result climate variability in
that interval is not due simply to forcing through insolation.
In the middle of 2002 Geoscience Australia made a transfer of assets
and so the Australian National Seismic Imaging Resource (ANSIR)
Major National Research Facility is now based at RSES in Earth Physics
with Porf. Kennett as Directror.
The facility sustains both reflection profiling equipment and portable recording
instrumentation for use in major field experiments.
Geophysical Fluid dynamics