To give your map the appearence that the floor is shaking in an area, have a floor hatch placed in the map, toggle doodad state, and either turn vision for that player on and off or do the detector trick so that the disabled floor hatch is invisible. If you want to stop the moving just make the unit disabled instead of toggled or remove the floor hatch.
Dosnt it say that it the Random Map Making Tip box thing...?
It did before... Judging from my list of all the tips, it isn't there any more.
Or... you could just simply place locations around the area you want to shake and center view on each location with a 500 millisecond wait or such
Yes, and to make the moving ground effects better, you should use an earthquake wav so you can actually "feel" it.
Here's an earthquake wav you all can have
[attachmentid=2520]
Simple way would be to do this, create a location, and even allow it to move, and then create a couple of observers, set to Junk Yard and give to Player 12, then get the triggers to centre your view on each one, really fast and remove them while moving the same location around onto them with the toggle effect and repeat it. Your fly around the map in no time.