1st, it seems WAY overpowered for the price.  Nukes buildings, changes terrain and kills monsters, over a wide area, and costs only 1.  The raise/lower land spells cost more to hit just one square.

Then, its a handy bug-workaround.  I had a semi-invisible spider in a forest along a caravan route.  Could see him only on the cloth-map, and nothing happened when I tried to attack him (several times, from diff directions).  Earthquake killed him.

It also got rid of the mountains that were completely blocking access to on a minor-faction city (sadly, I included the city in the area of effect and completely destroyed the city).

It changes forests to plains or hills, so now I'm testing to see if mass-deforestation will stop monsters from spawning where the forests were.  Ecology - what ecology