Alternate Title: National Oceanic and Atmospheric Administration Tsunami [website]
"A tsunami is a series of ocean waves generated by sudden displacements in the sea floor, landslides, or volcanic activity. In the deep ocean, the tsunami wave may only be a few inches high. The tsunami wave may come gently ashore or may increase in height to become a fast moving wall of turbulent water several meters high. Although a tsunami cannot be prevented, the impact of a tsunami can be mitigated through community preparedness, timely warnings, and effective response. NOAA has primary responsibility for providing tsunami warnings to the Nation, and a leadership role in tsunami observations and research." This website offers a variety of information about tsunamis, from the basics to preparedness methods and hazard assessments. There are several links to other resources on the local, state, and national level.
National Oceanic and Atmospheric Administration: http://www.noaa.gov/