Ah, in Mario and Luigi: Bowser's Inside Story, to perform the ground shaking attack, you need to press the X button right when Bowser's punch is about to land. It's all about timing and precision, just like when painting happy little trees. Keep practicing, and soon you'll master that powerful move!
First complete the 'Joint Tower' area as Mario, then press R as Bowser.
A seismometer measures the shaking of the ground.
magnitude
You can feel the ground shaking, objects shaking or rattling, hear a rumbling noise, or see items swaying. These are common signs that an earthquake has started.
I had Bowser's inside story but I forget what attack I used. I can tell you though that the attack where Luigi gets really fat and then bodyslams would probably shake the ground.
shaking ground and cracking
sudden shaking of the ground
Tremors
ground is shaking
seismogram
alot 9.8
The ground starts shaking lol