Why do Tsunamis pull back the water when they start getting closer to land?
In: Earth Science
A sea wave is an upward and downward movement of water.
To illustrate, go pinch the middle of your bedsheet and pull it upward. Watch what happens to the edge of the sheet.
Edit: As suggested by u/lightupsketchers the key thing I left out is that water molecules pull on their neighboring molecules, which makes them act like a sheet, for the purposes of this model.
It’s exactly like every other wave – if you watch one at the beach you’ll notice water pulling back just before a new wave crashes. It’s just a smaller scale than a tsunami.
The Tsunami is massive and it’s energy needs water from somewhere. That somewhere is the shallow water in front of the wave, which then comes back in a nasty way when the wave reaches shore.
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