Age-Dependent Seismic Thickness and
of the Australian Lithosphere
Department of Earth, Atmospheric and Planetary Sciences
Geophysical Research Letters, 29 (11), 1529, doi:10.1029/2002GL014962, 2002.
Massachusetts Institute of Technology (MIT)
Cambridge MA 02139, USA
We present constraints on the regional
variations of the seismic and mechanical thickness of the
Australian lithosphere. We infer the seismic thickness
from a waveform tomographic model of S-wave speed, and as
a proxy for the elastic thickness we use the wavelength at
which the coherence of surface topography and Bouguer
gravity drops below half of its long-wavelength
maximum. Our results show that on scales smaller than 1000
km the relationship between the age of the crust and the
thickness of the lithosphere is more complicated than
longer-wavelength or global averages suggest. Recent
geochemical and geodynamical evidence for small-scale
secular variations of the composition and stability of
continental cratons further illustrates the complexity of
the age dependence of seismo-mechanical lithospheric
properties on regional scales.
- Figure 01
Wave speed anomalies beneath Australia.
- Figure 02
Depth to the +1.0% velocity anomaly contour, a proxy for seismic thickness.
- Figure 03
Map of transitional coherence wavelengths, an indicator of the mechanical thickness.
- Figure 04
Average seismic thickness of tectonic subdomains.
- Figure 05
Average transitional coherence wavelength averaged over tectonic subdomains and grouped per eon.
- Figure 06
Transition wavelengths, seismic thickness, and their standard deviations, as a function of age.
Last modified: Wed Apr 12 23:06:25 EDT 2023