InfrastructureVideos of quakes 5.5 available for downloading 1.5 hours after occurrence

A Princeton University-led research team has developed the capability to produce realistic movies of earthquakes based on complex computer simulations that can be made available worldwide within hours of a disastrous upheaval.

The videos show waves of ground motion spreading out from an epicenter. In making them widely available, the team of computational seismologists and computer scientists aims to aid researchers working to improve understanding of earthquakes and develop better maps of the Earth’s interior.

“In our view, this could truly change seismic science,” said Princeton’s Jeroen Tromp, a professor of geosciences and applied and computational mathematics, who led the effort. “The better we understand what happens during earthquakes, the better prepared we can be. In addition, advances in understanding seismic waves can aid basic science efforts, helping us understand the underlying physics at work in the Earth’s interior. These visualizations, we believe, will add greatly to the research effort.”

In a scientific paper describing the system, which appeared online 16 September and will be published in the October 2010 Geophysical Journal International, the team describes how it creates the videos. The movies will be made available for free to scientists and members of the public and news organizations interested in featuring such images on television and the Internet. The easily downloadable videos can be viewed at: global.shakemovie.princeton.edu. They tell the story in a language that is easy to understand, said Tromp, who also is the director of the Princeton Institute for Computational Science and Engineering (PICSciE).

When an earthquake takes place, data from seismograms measuring ground motion are collected by a worldwide network of more than 1,800 seismographic stations operated by members of the international Federation of Digital Seismograph Networks. The earthquake’s location, depth and intensity also are determined. The ShakeMovie system at Princeton will now collect these recordings automatically using the Internet.

The scientists will input the recorded data into a computer model that creates a “virtual earthquake.” The videos will incorporate both real data and computer simulations known as synthetic seismograms. These simulations fill the gaps between the actual ground motion recorded at specific locations in the region, providing a more complete view of the earthquake.

The animations rely on software that produces numerical simulations of seismic wave propagation in sedimentary basins. The software computes the motion of the Earth in three dimensions based on the actual earthquake recordings, as well as what