This can either reduce or increase seismic activity, giving between a -1 and +1 to tasks this could affect. This can affect up to a 0.3 mile radius.

Control (Seismic Activity, Occasional) 3 [72] 
    Natural Phenomenon [+100%] 
    Magical [-10%] 
    Spell Components [-30%] 
        Must say "shake" in Latin 
        Must gesture with hands 
        Must hold a pinch of dirt, a rock and a lump of clay 
Level 2+ [+72/level) 
    Increase Control by 3 levels [+45 base]