Abstract by Malissa Alley
Physics and Astronomy
Monitoring Rock Arches Using a Laser Vibrometer
Utah is known for its many spectacular rock arches, and geologists want to understand and monitor their structural health. They do this by looking for downward shifts in the arches’ resonance frequencies overtime, which could indicate deteriorating structural health. Previous measurements of the arches’ resonances were done by placing a seismometer on the arches and measuring vibration from natural sources of vibration. However, it can be difficult to place the seismometer on an arch, and the seismometer may have been placed on a node of one of the arch's modes, meaning the geologists did not gain information about that resonance frequency. Alternatively, a scanning laser vibrometer can potentially be used to measure an arch's resonances. Having the advantage of not needing to be placed on the arch, the laser vibrometer can also do a full scan of the arch, which then depicts the actual shape of the modes of an arch, whereas the seismometer simply measured the resonances.