Satellites Measured Tsunami’s Height
January 12, 2005
by Kevin Caruso
Tsunamis can be large waves when they hit the shore, but the waves are actually relatively small when they are moving in the ocean.
Tsunami waves extend from the ocean floor to the water’s surface, unlike traditional waves which are surface-only waves. So a tsunami may be barely noticeable in the ocean.
The December 26, 2004, tsunami was caused by a large earthquake deep on the ocean floor, which resulted in the displacement of the water above.
Scientists who measured the tsunami with radar satellites found that the wave was about two feet high when it began; at 75 minutes it was 16 inches high; and at eight hours it was two to four inches high.
Because of the great depth of the wave, however, the tsunami greatly increased in height as it approached the shoreline; the shallower depths pushed the wave to the great heights that can be seen in various pictures and videos of the disaster.
