New computer models developed to analyze how seismic vibrations travel through Earth's crust can also be used to identify and track heavy vehicles such as tanks and trains.
Stig O. Hestholm, a seismologist at the Massachusetts Institute of Technology, and his colleague Bent O. Ruud of the University of Bergen in Norway developed new formulations of equations for estimating the effect of hills and valleys on the magnitude of ground motions caused by earthquakes. In their model, the researchers use a large, three-dimensional grid to represent a section of Earth's crust. They can shape the upper surface of the grid to match any terrain.
Supercomputer simulations of seismic waves traveling through the grid show that ground motions are greater atop hills and smaller in large basins or valleys compared with flat terrain. This type of information could be useful in disaster-response planning and establishing building codes, says Hestholm.
The same modeling techniques cou