At the top left, there is a "beach-ball", or more properly a lower-hemisphere projection of the Harvard Centroid Moment Tensor for an earthquake. In particular, this image is for the June 9, 1994 Bolivia Earthquake, which was the largest earthquake since 1976 (Mw=8.3). The beach-ball shows the possible fault planes for the earthquake, one a near vertical plane, with an east-west orientation, and the other a horizontal plane. The red and white regions show that, if the motion where on the vertical plane, the direction of motion above and just to the north of the epicenter would be downward.
The seismogram is the vertical compoenent of station HRV (Harvard, Massachusetts) of the Bolivia earthquake. The Harvard station is close to due north of the epicenter. The P-wave is quite strong (under the H), and the large arrivals are shear waves.
The maps on the right are pictures of the model S12, a model of the seismic wavespeeds in the interior of the earth. The model on the upper right shows isosurfaces, with the red corresponding to regions 0.5% slower than the average and the blue corresponding to regions 0.5% faster than the average. The center of the image is the western Pacific. The image at the lower right is the same model, this time as if we had taken a slice into the earth. The fast speeds are in blue, average in yellow, and slow in red. The projection is the same as the other, and the cut-out extends to the core-mantle boundary.
At the bottom of the page, is a power spectrum of the same seismogram as is on the top. An alternative way of considering seismic motions in the earth is as modes, just like (for you physics students out there) the vibrations violin string can be analyzed as waves or modes. The peaks are the natural frequencies of the earth's vibration. The freqency range shown is 1.5mHz to 6.0mHz.
All images were created by Erik Larson, with the maps of S12 from Wei-jia Su.
