Q. Tsunamis can have wavelengths between 100 and 400 km. Since this is much greater than the average depth of the oceans (about 4.30 km ), the ocean can be considered as shallow water for these waves. In shallow water of depth (d) the speed of waves is approximately v=sqrt(g*d). Find the typical speed for a tsunami. (Note down that in the open ocean, tsunamis generally have amplitude of less than a meter, allowing them to pass ships unnoticed. As they approach shore, however, water depth decreases and the waves slow down. This can result in an increase of amplitude to so far as 37 m or more.)