The massive security operation surrounding Barack Obama's inauguration showed that he will be the most protected president in the history of the United States. Photo: REUTERS.
The physics of a tsunami. Tsunamis can have wavelengths ranging from 10 to 500 km and wave periods of up to an hour. As a result of their long wavelengths, tsunamis act as shallow-water waves. A wave becomes a shallow-water wave when the wavelength is very large compared to the water depth. where g is the acceleration due to gravity (= 9.8 m/s2) and H is the depth of water.
The gauge in Coquimbo, Chile, recorded three tsunami waves of at least 4 meters (13 feet) each, including a maximum tsunami wave height 15.1 feet above normal tide levels. Several other Chilean coastal cities have recorded tsunami waves as well, though none nearly as dramatic as those in Coquimbo.