Subterranean strike is a support power that causes large drills to unburrow at the target location, dealing massive damage to enemies on the surface. While it requries less support points and has a wider range then Tiberium Vein Detonation, it is mostly used to kill infantry (Mostly large groups of Engineers that some defence players use to keep their buildings at full health) and to finish off badly damaged vehicles. Players can unlock the achievement Power Tools by dealing a certain amount of damage with this power.
If playing a match with 2 Nod support crawlers, consider having one player use the Tiberiam Vein Detonation power, and the other following up with a Subterranean Strike. The corrosive effect from the vein detonation will increase the damage of the strike, and the two powers combined are a powerful enough to kill any land unit or structure in the game, even crawlers. This also does more overall damage than a pair of vein detonations.