De Paor, D. 2008. Enhanced Visualization of Seismic Focal Mechanisms and Centroid Moment Tensors Using Solid Models, Surface Bump-outs, and Google Earth. In: (Ed.) Declan De Paor, Google Earth Science, Journal of the Virtual Explorer, Electronic Edition, ISSN 1441-8142, volume 29, paper 2, doi:10.3809/jvirtex.2008.00195
Enhanced Visualization of Seismic Focal Mechanisms and Centroid Moment Tensors Using Solid Models, Surface Bump-outs, and Google Earth
Abstract
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.
Table of Contents
- Introduction
- Building solid models of focal mechanisms
- Representing the subsurface in Google Earth
- Importing focal mechanism models into Google Earth
- Specifying event location and altitude
- Representing moment magnitude and orientation
- Adding focal plane solid models
- Representing non-double-couple centroid moment tensors
- Relating nodal planes and surfaces to first arrivals
- Event times and timespans
- Real-time monitoring
- Shake maps and community feedback
- Conclusions
- Acknowledgments
- References