o.O Its nigh impossible to counter those types of moves since it involves the ground, and you'd be trying to counter the ground, not your opponent. It takes a supercreative position in order to counter Earthquake (wrestling mat comes to mind..), but Fissure, naa. Magnitude, not really either...

That being said, yeah Sandstorm only raises Spec Def of Rock Pokemon ¬¬ Learned that the hard way, stupid Wishcash...