High-frequency ground motion from Australian earthquakes

The dominant high-frequency component of ground motion for most seismic events in Australia comes from the crustal Lg phase that can commonly propagate efficiently to considerable distances across the continent. Using results from recent tomography for the attenuation of Lg, we are able to build the pattern of transmission of ground motion from events within the continent. The effects are readily displayed in terms of a distribution of effective magnitude. The same approach can also be used to look at the cumulative effects across the continent from 1840 to date as a useful complement to other ways of assessing earthquake potential.