Seething Volcanics

Seething Volcanics enters the battlefield tapped.
Whenever 6 or more land tap on one turn, search
your library for a card with converted mana cost
8 or more and put it into your hand. Then, untap
all tapped lands.
Red and blue creatures you control get +2/+0.
{t}: Add {u}{r} to your mana pool.