ERTH 2415 Lecture Notes - Lecture 7: Bathymetry, 2004 Indian Ocean Earthquake And Tsunami, Eurasian Plate
27 Mar 2018
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Document Summary
Geographical occurrence: pacific ocean surrounded by active volcanoes and subduction zones, 80% of the world"s earthquakes have their epicenters around pacific ocean. Wave characteristics: amplitude, maximum value measured from the equilibrium, attenuation: loss in amplitude as the wave propagates away from its source. Characteristics of ocean waves: characteristics common to all waves propagating in the open ocean, water moves in forward-rotating circles, diameter of circles creases with depth, negligible for depth > l/2. Shoaling: shoaling occurs when waves interact with the seafloor near the shoreline. Interaction starts when depth < l/2: friction slows wave down, wavelength decreases, energy is concentrated in a shorter length, amplitude increases, wave breaks. Tsunami waves: mostly created by underwater disturbances of the seafloor, amplitude. Early warning systems: pacific tsunami warning center (1948, screen earthquakes. Identify earthquakes which meet criteria for generation of a tsunami: epicenter under water, magnitude > 7. 5, predict arrival times at selected coastal communities.
