EarthScope USArray seismic stations create a dense array of detectors that can collect high-resolution data from earthquakes worldwide. The number of seismometers in given location is similar to the number of pixels on the sensor in your digital camera. The more pixels (seismometers), the better the resolution.
The movie shows the actual seismic data collected from the February 21, 2008 magnitude 6.0 Wells, Nevada earthquake. This earthquake occurred in the center of the USArray Transportable Array. The three dimensional aspect of seismic waves traveling outward is easy to see visually.
Each of the dots is a seismometer. As the seismic waves pass, the instruments move up and down (indicated by the changing colors). If a dot turns red, the seismometer is moving up. If a dot turns blue, the seismometer is moving down.