ERTH 2415 Lecture Notes - Lecture 6: 1985 Mexico City Earthquake, Strong Ground Motion, Mercalli Intensity Scale
4 Oct 2016
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Document Summary
Erth 2415 class 6: earthquakes, people, and infrastructure. Mercalli intensity scale (1902 modified in 1956) a descriptive and subjective scheme with twelve divisions of increasing intensity based on: Intensity: measure of the effects of an earthquake on people and infrastructure. For a given earthquake, there are several intensity values (depending on the location) but only one magnitude. Magnitude: total amount of energy released during fault rupture. Isoseismal maps: a map based on input from the public, it summarizes intensity reports through mercalli intensity scale. Information from public about earthquakes is used to establish a correspondence between recent and historical earthquakes as well as to determine how an area may respond to future earthquakes. Example form 2010 val-des-bois, quebec earthquake based on ~5200 did you fell it? questionnaires. The data received is georeferenced using postal codes. Shakemap: intensity map generated automatically using data from networks of seismograph stations. Inputs ground motion data and knowledge of regional geology.
