12? It's much more than that. A Magnitude 9 earthquake is 1,800 megatons.
The largest nuclear weapon ever detonated was 50 megatons (and that was a one-off stunt by the Russians that wasn't a real weapon.) This quake was the power of 36 of those.
The thermonuclear warheads we have on our missles (minuteman and Trident) are 300 kilotons.
Thus, this quake was as powerful as about 54,000 warheads from American ICBMs. Or many times more powerful than every single nuclear weapon on the world going off at once.
Magnitude 9.0
Energy Equivalent Weight of TNT* 32,000 mtons
Energy in Joules 0.200E+19
10,666.6667 300 kton warheads
but who's counting - it makes one hell of a mess.
2 pentillion watts of energy released