Earthquake like spell that damages units?

Is there any way to do this without triggers? I can't seem to find the earthquake effect anywhere so I can't assign it to something like blizzard. If someone has any ideas I'd love to hear em.

Yes there is a way to do this without triggers if it is a blizzard style spell that you want to use you need to edit the external file, Units\neutralabilityfunc.txt if you want to use rain of fire, for blizzard you edit the file Units\humanabilityfunc.txt.
The earthquake spell effect is Abilities\Spells\Orc\EarthQuake\EarthquakeTarget.mdx

If you have The Frozen Throne this is EXTREMELY easy. All you have to do is to go to the object editor and to the abilities tab. Then go to orcs, hero's, and earthquake. Scroll down a little bit and all you have to do is change the targets allowed to units, hero, ect.