Tidal-Waves are indeed “Pressure” or “Shock Waves”
(over simplified commentary)

The wave of water that moves across a land mass or crashes onto a shore is the
result of the friction the shockwave has as it moves through the water.  First
t is shoving water, so water is displaced in its path and has to be moved aside
creating a wall of water.  The movement of the shockwave also creates induced
drag which pulls water along with it.

There is also a vacuum that I creates as part of a frontal wake.  This is why
the water is  usually pulled away from the shore as it approaches.  This had to
do with fact the water is becoming shallower, and the coefficient dynamic of
the energy within the wave.  This same effect happens with regular waves at the
beach, which is all a dynamic equation of the exchange / discharge of energy.

The Pressure or Shockwave are typically created by:
a) Collapsing walls of a volcanic mountain (minor)
b) Eruptions of magma on the ocean floor or volcanic mountain, which produces
an explosion steam.
c) Other Geologic Events

Leslie

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