An ANU seismologist whose work could help forecast the damage path of future earthquakes has been honoured by one of the world’s top scientific organisations.
The Royal Astronomical Society (RAS) in London has awarded its 2008 Gold Medal for Geophysics to Professor Brian Kennett, Director of the Research School of Earth Sciences at ANU. In the citation, the researcher is described as “one of the most complete seismologists of his generation”.
Professor Kennett works on determining the structure of the Earth using the waves generated by earthquakes and man-made sources. His reference models for the structure of the Earth have been adopted as standards for the location of earthquakes across the globe, and are widely used in imaging the planet’s interior.
“It’s an honour to be recognised for my work by the Royal Astronomical Society, but the best reward is learning more about the powerful forces at play within the Earth,” Professor Kennett said.
“Some of my recent work in cooperation with Japanese colleagues has shown how the ground motion generated by a large earthquake is affected by Earth’s structure.
“With three-dimensional computational models it’s now possible to simulate the effect of possible earthquakes to assess likely patterns of damage. For example, puzzling observations – such as strong ground motion on the east coast of Japan from earthquakes at 600 km almost beneath China – can be explained by guided waves trapped with the descending Pacific Sea plate.
Professor Kennett’s work combines theoretical, computational and observational approaches to gain comprehensive information about the three-dimensional structure within the Earth on scales from local, through regional to global. He has worked on the techniques of seismic tomography, where structure is reconstructed from the properties of the seismic waves passing through it a similar way to a CAT scan in medical work. “Such studies reveal the detailed properties of the subduction zones that generate great earthquakes, such as the 2004 Sumatran-Andaman event that produced the devastating tsunami across Southeast Asia,” Professor Kennett said.
He has also led a major program of work on the structure of beneath the Australian region using deployments of portable instruments that provide high-fidelity recordings of earthquakes. The analysis of the seismograms recorded by these instruments has revealed strong contrasts at depth beneath Australia that link to the ages of rocks exposed at surface.