Over the past several years, we have developed a 2D model of intraoceanic subduction using a marker-in-cell technique1. In order to resolve both large and smallscale features (Figure 1) in and above the subducting slab, we have performed runs of this simulation using as many as 40 billion tracers. Although there are many 3D visualization packages available for datasets of this size, we found existing 2D visualization solutions to be lacking and therefore developed our own high resolution 2D visualization software. This software, WEB-IS42 (Figure 2), uses an hierarchical data format3 to achieve response times on the order of 0.1s, including dynamic colormap application and data analysis, when retrieving arbitrary regions of interest from 10 billion-element datasets over the web. The WEB-IS4 backend includes the ability to browse through multiple timesteps and multiple fields and to simultaneously display information relating to multiple fields, such as temperature and chemical composition. WEB-IS4 is dataindependent and could easily be used to display large 2D datasets from remote sensing, astronomy, geology, or medical imaging.