Large Meteor Impact and World Damage

[sirsig]

Hey, Ive been toying with the idea of a large meteor impact for my campaign world when trying to ascertain a world map from the continents.

The idea is the main landmass was a Pangaea style continent until the meteor hit and made a crater around 3000kms (open to size change) radius.

The attached image gives a vague idea.

Dead centre is a bunch of islands / archipelago.

Now considering the impact im trying to envision a real world kind of result in the landmasses that survive ie more islands and where they would sit.

Any input would greatly be appreciated.


ps. the pic is a quick dirty scribble in PS to give a rough idea. There's now 3 main continents and main rpg action is the one on the right.