Earthquakes are clustered along fault lines. Showing the quantity and magnitude of earthquakes cumulatively over time is a challenge due to visual overlap.  There are over 234,000 earthquakes in the database. There is not enough screen resolution to show every earthquake distinctly. Drawing the symbols sequentially would obscure the oldest earthquakes and show only the most recently drawn. The visualizations are drawn in the Paraview software application. The imagery is texture mapped onto a plane so it can be viewed in 3D. This provides an additional dimension for showing the quantity and magnitude of geo-located data.  These images show our approach to solving the visualization.   ( note:  Images are shown half-size.  Download the images to display at full resolution. )

Here are all earthquakes above magnitude 5.

The 4.5 - 5.0 range is displayed with even more transparency to avoid obscuring the other ranges. Outlining the edge of each triangle clarifies multiple co-located earthquakes of high magnitude. The terrain imagery is from the NASA Visible Earth, Blue Marble collection. We have combined it with bathymetry (ocean depth) data from the Geophysical Fluid Dynamics Laboratory. Darker blue indicates deeper ocean floor. We see some earthquake concentrations along deep ocean trenches while other fault lines are in shallow areas and along coast lines. Seismic data was extracted from the US Geological Survey earthquake catalog.