How long would it take a region to geologically settle down after a major cataclysm?

So in my story/world I have a region that is straight up destroyed...demonic magic is nasty stuff.

So we have rings

Ring 1 (1 is in the middle)

This ring has a diameter of about 200 miles. At this range things got real real bad. The land that was here was completely gone, either ejected into the sky in massive chunks or sunk below the oceans. It is not on the Richter scale at all...

Ring 2

Ring 2 is an additional 100 miles around so the total diameter from the center would be 300 miles. At this range the entire area experienced the equivalent of a 9.0 - 10.0 earthquake per the Richter scale.

Ring 3

Ring 3 adds an additional 50 miles to the radius, for a total of 350 from the epicenter and experienced 8.5 - 9.0 Magnitude quakes

Ring 4

This ring adds another 200 miles for a total range of 550 and its quake measurements registered 6.5 to 8.5

Ring 5

Ring 5 is a more general idea than a specific range. Quakes in this area which doesn't have a specific mileage ranged from 2.0 - 6.5

Questions:

1. How long would it take this region (by ring if necessary) to settle down to the point of human habitability?

   • My goal is it should be 500 years in rings 1 and 2 before its even safe to walk around, be that lava, gas, tremors etc
   • An additional 500 - 1000 years before non-human life will live there.

If my plan doesn't work in the regard, please suggest what ranges/etc could make that work.

2. What would be the hazards in the region prior to things settling down?

   • Would there be magma pools, noxious gasses, steam from magma and water coming together? Stuff like that...

Assumptions:

• Magic was involved so there will be no nuclear winter follow on. I am purely asking about the geological stability of the region and any associated hazards spawned from that.

• The ground is scorched and dead out to around 300 miles from the epicenter (meaning all the living stuff in the dirt died)

posted almost 8 years ago

James‭

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