How do p waves move the ground?
P waves are push-pull waves
It causes the rock to move back and forth in the direction waves are moving.
Look at this diagram, As the p waves travel, it moves the rock particles into the particles ahead of them then compresses it. Then the rock particles will bounce back causing them to hit the rock particles that pushes them forward.
See the explanation.
p ( primary ) - waves are more powerful and faster than the s (
secondary ) waves that emanate from the p-waves.
p-waves are in the class of longitudinal waves.
Just above the epicenter (source point) the p-waves strike the
surface of the earth, in the vertically upward direction. This is
just opposite to the direction of gravity,
And so, the displacement of matter will be in this direction. As we
move away from this right-above-epicenter area, this direction
gradually turns away from this vertical. Of course, for the resultant
displacement, the medium thereupon matters.
The displacement for rigid bodies might be disintegration under the
pressure of these vertical or inclined p-waves..
p-waves might travel at speeds in the range 5-8 km sec (up to
about 25K '/s). Seismic p-waves might travel in granite at 20K'./s .