Subject: What was the largest known explosion to occur on the Earth?

What was the largest explosion believed to have occured on Earth?  Would that 
have been the 'dinosaur killer'?  If so, what were the physical effects on the 
planet, exactly?  What size crater was made, and how far do they think the 
shockwave travelled from ground zero to damage other objects?  What was the 
estimated yield of that blast?

Re: What was the largest known explosion to occur on the Earth?