Seismic sensors installed at the surface, and at various depths within the different geological layers below, provide researchers with valuable information about how the near-surface geological conditions affect incoming earthquake ground motions. This visualization shows actual observations from the NEES Garner Valley monitoring facility, which consists of many sensors located at various depths below the surface. The soil below the surface, having been deposited over1000's of years throughout geological time, has varying composition, and these differences affect the way that the waves propagate up from the rock below to the soil surface. The animation shows observations of a magnitude 4.1 earthquake only 26km away from this site. The animation ties the context and observed data in an intuitive way. It also provides insight about ground motion at various depths below the earth surface. You will notice that the ground motions are smallest at the bottom within the crystalline bedrock, and increase as they propagate up through the soil layers, becoming largest at the surface. This explains soil amplification to viewers with simplicity . Furthermore, it is easily evident from the animation that the horizontal components (north-south and east -west) components have higher magnitude of motion than vertical components. This information can be used to further explain the surface and body waves to the audience.
Credits and References
Visualization : Amit Chourasia, SDSC/ UCSD
Science Advisors: Jamison Steidl and Sandra Sealy, ERI / UCSB
Funding: This project was supported by the George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES) Program of the National Science Foundation under Award Numbers CMS-0217421, CMS-0402490, and CMMI-0927178
Project Website: http://www.sdsc.edu/us/visservices/projects/nees-ucsb
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