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.
Tsunamis are long-wavelength, long-period sea waves produced by the sudden or abrupt movement of large volumes of water. In the open ocean the distance between wave crests can surpass 100 kilometers (62 mi), and the wave periods can vary from five minutes to one hour.