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As the speed of shallow-water waves depends directly on water depth.
In the open ocean , tsunamis travel at a rate of around 760 kilometers
per hour , a speed comparable to that of modern jet aircraft ! and , in
shallow water , they slow down appreciably , because the water depths
that control their speed are so slight.
Although little can be done to avert the generation of tsunamis, efforts
can be made to minimize their distructive effects . One approach – the
international Tsunami Warning System- is a network of stations taht
measure and record the vibrations of the crust to detect large
earthquakes in the ocean and predict the occurrence of tsunamis. Coastal
araeas likely to be struck by the seismic sea waves are then alerted ,
permitting the evacuation of people and ships in harbors . This
international warning system , coupled with evacuation training , the
relocation of coastal houses and villages , and engineering structures to
absorb or reflect
the energy of tsunamis , has proved to be quite
effective in some cases.
(source : invitation to oceanography .2006.p :251,257,259)
Exercises :
exercise : fill in the gaps with the right words :
1-…………………..are sudden changes of coastal water levels
produced by storms.
2-The most common type of water wave is…………………….
3-……………………………..is a wave with a period of less than half a
second , and they are more apparent when water is …………….and
……………
4-…………………………are shallow water waves , they have a
distinct crest but no trough.
5-Giant waves are described so , because of their…………………, they
are also called …………………
6-Large supertanks are ………………..to rogue waves.
7-Smaller vessel can ride up and down giant waves ………………….,
provided that the wave is not………………. Supertanks can not do this