Announcing Shakemovie.caltech.edu

Announcing shakemovie.caltech.edu – Caltech’s near real-time simulation of Southern California Seismic Events Portal.

ShakeMovie is a new portal, serving movies made from simulations of earthquakes of magnitude 3.5 and above happening in the Southern California Region, only 45 minutes after the actual event.

This portal has been designed to present the public with near real time visualizations of recent significant seismic events in the Southern California Region. These movies are the results of simulations carried out on a large computer cluster. When an earthquake occurs, seismic waves are generated which propagate away from the fault rupture.

In the example shown above – a magnitude 5.0 event from Feb 22, 2003 centered three miles north of Big Bear City, CA (click for ~5MB mpeg movie file) – we see the up-and-down velocity of the Earth’s surface. Strong blue waves indicate the surface is moving rapidly downward. Strong red waves indicate rapid upward motion. When the waves pass through soft soils (sediments) they slow down and amplify. Waves speed up when they pass through hard rock. The color of the waves oscillates between red and blue indicating alternating up and down motion.

Shakemovie was created by Caltech’s Seismological Laboratory, Instrumental Software Technologies, Inc. and Caltech’s Center for Advanced Computing Research. The project is sponsored by the United States Geological Survey, the National Science Foundation, Dell Inc, and the Southern California Seismic Network.

ShakeMovie is found at: http://shakemovie.caltech.edu.

Making the Sumatra Movies

click for mpg movie
[36MB mpeg]

Snapshot from a spectral-element simulation of the Great 2004 Sumatra- Andaman earthquake. Shown is the vertical component of velocity 15.8 minutes after the initiation of the rupture. Red colors denote upward motion and blue colors denote downward motion. Stations in the Global Seismographic Network are denoted by the yellow triangles. The yellow seismogram shows the actual-size vertical component of displacement at GSN station PALK.

Dramatic new data from the December 26, 2004, Sumatran-Andaman earthquake that generated deadly tsunamis show the event created the longest fault rupture and the longest duration of faulting ever observed, according to three reports by an international group of seismologists published Thursday in the journal ” Science .”

The visualization was prepared by Santiago Lombeyda ( CACR ), Vala Hjorleifsdottir (Caltech Seismological Laboratory), and Richard Aster (New Mexico Tech). The simulation was performed on the Caltech Division of Geological & Planetary Sciences Dell cluster.

Further information about the simulation can be found on Santiago Lombeyda’s website , including links to a CNN news item and a Caltech press release .