This paper presents a parallel visualization pipeline implemented at the Pittsburgh Supercomputing Center (PSC) for studying the largest earthquake simulation ever performed. The simulation employs 100 million hexahedral cells to model 3D seismic wave propagation of the 1994 Northridge earthquake. The time-varying dataset produced by the simulation requires terabytes of storage space. Our solution for visualizing such terascale simulations is based on a parallel adaptive rendering algorithm coupled with a new parallel I/O strategy which effectively reduces interframe delay by dedicating some processors to I/O and preprocessing tasks. In addition, a 2D vector field visualization method and a 3D enhancement technique are incorporated into the parallel visualization framework to help scientists better understand the wave propagation both on and under the ground surface. Our test results on the HP/Compaq AlphaServer operated at the PSC show that we can completely remove the I/O bottlenecks commonly present in time-varying data visualization. The high-performance visualization solution we provide to the scientists allows them to explore their data in the temporal, spatial, and variable domains at high resolution. The new high-resolution explorability, likely not available to most computational science groups, will help lead to many new insights.