Air Pressure in Canyons in varying circumstances?

Question

Would there be a difference in air pressure in a canyon;

Below Sea level?

Above Sea level?

Also what would happen if say there was no 100% Co2 on earth & you pumped air into say the Grand Canyon, & damed it at ether end.
Would it Pool? would it Rise strait up? would it overflow?
could you breath the air? what sort of (simplified) sums could you do to figure out how high you could go in the canyon b4 it was un breathable? & would gravity have an effect ? Also how would you calculate that into the sum?


p.s Dont worry about the How we get air & sutch... just would it stay basicly, & would it need to be replenished or would plants be able to sustian it?

kinda like what the Aztechs did with those micro climate gardems up the mountains.. just wondering.. need more facts! thanks.

& no i cant spell spent to mutch time plaing paintball..

Answer 1

Pressure varies with altitude, even a small change in altitude has a small change in pressure, so yes, there's a difference.

CO2 is heavier than air, so it tends to pool. However, over time it disperses, so gases don't stay where you put them.