Enhanced Visualization of Seismic Focal Mechanisms and Centroid Moment Tensors Using Solid Models, Surface Bump-outs, and Google Earth

Declan G. De Paor

Novel methods for representing earthquake focal mechanisms and centroid moment tensor solutions on virtual globes such as Google Earth™ are introduced. Using solid models and surface bump-outs in conjunction with Keyhole Markup Language (KML), geophysical “beach balls” and other representations of centroid moment tensor solutions may be projected in the Google Earth application so that they appear in the correct orientation at the epicenter location at the source event time. Because the Google Earth virtual globe’s surface is opaque, sub-surface data are vertically displaced and a color-coded depth scale is added. The four-dimensional pattern of seismicity in a region may be better understood with the aid of KML’s timespan tags which cause data to appear in chronological sequence. Future earthquake and tsunami hazards may be monitored in near-real time on any desktop, laptop, or handheld device that is capable of viewing either the Google Earth virtual globe, or any other KML-savvy virtual globes, such as NASA World Wind.