Definition of Tsunami: "Japanese, from tsu = harbor + nami = wave, meaning a great sea wave produced by submarine earth movement or volcanic eruption." When the subducting Nazca Plate moved a large volume of water was displaced. When a tsunami is born it is not felt by people further out at sea, but when the wave gets closer to the shoreline it reaches a half-way point. At this point the diplaced water is pushed up by the shallow depths and creates the "white caps" that are significant wave features. A series of tsunami hit the coast of Valdivia on May 22nd, 1960.
It took 10 to 15 minutes for the series of tsunami to reach the coast of Valdivia. There were three tsunami that hit the coasts, each one taller than the one before; first a 5 m high wave, next an 8 m high wave and finally an 11 m high wave. The picture below shows the before and during pictures of the second ( 8 m ) tsunami, it was taken from a cliff 30 m above normal sea level in the Gulf of Corral straight west of Valdivia's city center.
(Source : http://www.ngdc.noaa.gov/seg/hazard/slideset/45/45_slides.shtml )
When a tsunami hits a shoreline there is always a run-up path that does the most damage to a coastline. In Valdivia there was a maximum 10 m run-up path after the three waves hit. The run up diplaced the Valdivia River, creating more smaller waves as it moved inland. Structures and houses that were built on the riverbank were heavily damaged. The picture below is of the Valdivia River flooded after the water run-up devastated the riverbank structures.
