Visualizing Earthquake Locations in an Immersive Learning Environment

Abstract:

Visualizing world-scale geospatial datasets (i.e., subsurface data) in immersive VR (iVR) is challenging in terms of system requirements and user experience while keeping high performance graphically. Creating a good user experience requires fitting a world-scale dataset into a small play area in a way that is understandable, interactive, and provides a natural manipulation of the data. Scientists frequently visualize geological data as 2D representations, which creates a challenge for some students to visualize and understand the spatial phenomena' arrangement in time and space. For instance, undergraduate students in geosciences learn about plate tectonics, which is inherently three-dimensional, plotted on maps and block diagrams. As part of an introductory Geoscience course at the PSU, we developed an iVR visualization using USGS' Centennial Earthquake Catalog, supporting students to understand plate tectonics and cross-sections at earthquake locations across the world. The immersive learning environment's design encourages students to switch between multiple datasets (earthquake locations, plate boundaries, and Holocene volcanoes) to synthesize all datasets—the USGS Earthquake Catalog containing earthquake locations from 1900 to 2008 with a total of 13077 points. The earthquakes and volcanoes were visualized in the form of georeferenced point clouds with various color-coded values in iVR. To overcome the performance limitation on rendering a large dataset in VR, we used particle systems to generate points with a limited lifespan to ensure efficient performance. Students could drag and scale the datasets in every direction and physically walk around and inside the datasets to carefully observe the 3D structure of the subduction zones. In a pilot study comparing the plot of South America and Japan drawn by students in two conditions, iVR and a 2D representation, students reported that iVR creates a better learning experience in terms of mental imagery and reflective thinking. Also, iVR as a learning medium had a positive effect on understanding the geometry of at earthquake locations in a complex tectonic environment such as Japan.