Field of Research:
Geophysics
In Germany:
01.08.2011 -
31.10.2011
Host's project description
Professor Kennett is one of the most highly regarded seismologists. Much of what we know about the Earth comes from careful studies of the way seismic waves travel through our planet. Over the course of a most distinguished career Professor Kennett has made major contributions to advance these studies. His research has revealed the structure of the Earth through tomographic studies of the Earth's mantle, he has contributed one of the most widely used elastic 1-D Earth reference models (iasp91) to compute seismic travel times through the Earth's mantle, and he greatly advanced our understanding of the density distribution inside the Earth. For Australia, his home country, the tomographic studies reveal a complex flow pattern as the continent moves about the underlying mantle. For the whole Earth the studies provide estimates on the temperature distribution with depth, the so called geotherm. They also suggest a profound change in the the nature of heterogeneity in the lower 1/3 of the Earth's mantle. Equally important is his work on the fundamental principles of seismic wave propagation. His work has allowed a far more realistic computation of synthetic seismograms, paying special attention to the complexities arising from the strong heterogeneity that are present inside the Earth. These theoretical advances have influenced an entire generation of seismologists. They are embodied in a two-volume book, "The seismic wavefield", which is one of the most widely used textbooks in the field.
Because structure of the Earth must be inferred from observations obtained at the surface, inverse theory plays a central part in geophysics. Professor Kennett has worked extensively on inverse theory. He has paid special attention to the treatment of nonlinearities. And he addressed the problem arising from inversions where several classes of model parameters must be inferred simultaneously. Among others, this has enabled new tomographic models based on both P and S wave data to compute the bulk sound and shear wave speed distribution inside the Earth. Since compressional (P) and shear (S) waves react differently to compositional and temperature variations these new models have enabled a much improved understanding of the distribution of thermal and chemical heterogeneity inside the Earth.
For his many scientific contributions Professor Kennett has been honoured numerous times. He is
an elected fellow of the American Geophysical Union and of the Australian Academy of Sciences and also a recipient of the Centenary Medal of the Commonwealth of Australia. Last month Professor Kennett has been elected a Fellow of the Royal Society in the United Kingdom.
During his stay in Germany his work will focus on linking seismological earth models
with geodynamic models of the Earth in a quantitative way. Geodynamic models, so called circulation models of the Earth's interior, have achieved great realism over the past years providing independent constraints on the density and temperature distribution inside the
Earth. The collaboration will mesh the complementary constraints from seismology and geodynamics on gross Earth structure for which Professor Kennett and Professor Bunge, his host in Munich, are known. In addition Kennett and Bunge will co-author a graduate text book on seismology and geodynamics.
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