Electronic Thesis and Dissertation Repository


Master of Science




Dr. Gail Atkinson


With widespread Internet use, web-based earthquake reports are a valuable source of felt intensitydata with broad geographical coverage. Paired with ground motion data, Internet surveys like theUSGS Did You Feel It? (DYFI) website can be used to derive relationships between ground motionparameters and Modified Mercalli Intensity (MMI). These are particularly important for regionswith sparse seismographic coverage where the quality and density of intensity data may be superiorto ground motion data. MMI-ground motion relationships are also needed to infer ground motionsof historical earthquakes.

Using well-documented earthquakes in across North America, we analyze correlations betweenfelt intensity and ground motions, including peak ground acceleration (PGA), peak ground velocity(PGV), and spectral acceleration (PSA) at 0.3, 1, and 3 seconds. These relationships are exploredusing correlations, linear regressions, and geostatistical methods. Magnitude, distance and sitee ects are analyzed, and Kriging is used to explore interactions among these variables.