EOSC 114 Lecture Notes - Lecture 7: Seismology, Base Isolation, Vibration Control
22 Jan 2018
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Document Summary
A quantitative measure of energy release by the earthquake. Proportional to energy release and depends on: rock strength x fault area x fault slip. As magnitude increases the earthquake: affects broader region, shakes ground longer, causes more damage. Remember: unit magnitude increase equals 3. 2 x longer shaking, 10x stronger shaking and 32x more energy released. Qualitative estimate of how ground motion affects population and structure. It is what we feel in an earthquake, your perception of ground shaking. The damage resulting from the vibrations: ranges from 1 to 12. Short=less intense; long=more intense: some earthquakes have several minutes of shaking, structural damage, more damage we see the larger the perceived intensity of the earthquake. Structural damage is cause by shaking: structures are designed to take a vertical load, earthquake waves shake the ground vertically and horizontally, horizontal shaking is nasty, the longer a building shakes the worse the damage is.
