This animation shows the USGS SAFRR tsunami from generation through about 8 hours of propagation. The initial images of the animation show the ocean surface elevation right after the earthquake. The water colored in red indicates high positive elevation water (crest), while the dark blue colors show the low negative elevation water (trough). Initially, the tsunami spreads radially, with some directional focusing along the long axis of the earthquake. As the wave moves through the pacific, traveling at ~500 mph, the wave energy remains concentrated in the initial, leading pulse; this is a classic property of a tsunami, and why it can affect distances very far from the earthquake. As the wave reaches the shoreline, watch as the height grows. This is called "shoaling" and is a result of the front of crest moving more slowly than the back part of the crest, compressing the wave energy in the horizontal direction, and causing it grow in the vertical. Tsunami energy is "trapped" near the coastline, and large waves can be seen well after the first waves - the first wave is often not the highest. More information about the SAFFR project can be found here: http://pubs.usgs.gov/of/2013/1170/

• published: 03 Sep 2013
• views: 819