Is "much" used for emphasis in "much to your surprise"?
Solution 1:
"Much" is added for emphasis here.
It's normal to say "Much to my surprise" (which means "I {am/was} very surprised"), but not at all idiomatic to say "Much to your surprise". For that, you'd say "You'd say something like "You'll be surprised to {hear/learn/know} that he's still alive".