# The Naked Scientists Forum

### Author Topic: Atmospheric Pressure  (Read 2102 times)

#### moonfire

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##### Atmospheric Pressure
« on: 24/05/2007 15:27:18 »
What if the sea level drops, how much change will it cause?

#### another_someone

• Guest
##### Atmospheric Pressure
« Reply #1 on: 24/05/2007 16:32:45 »
Of itself, it depends on how and why the drop in sea level.

Atmospheric pressure depends on two factors - the amount of air above your head, and the density of that air.

Simply removing water from the sea, if their is no change in the volume or density of the air, will have no effect on air pressure (i.e. the air will drop in line with the drop in sea level, so the air pressure at sea level will remain the same, although if you live up a mountain, that mountain will have risen in relation to sea level, and so the local air pressure would have dropped slightly at that locality).

If the sea level drops because the water has evaporated, then the water becomes a part of the atmosphere, so you now have more atmosphere above your head (whether that is an increase in density or and increase in volume depends on various factors, although I would normally expect an actual decrease in density, and greater increase in volume).

#### moonfire

• Neilep Level Member
• Posts: 4597
• Can't stand the heat, step away from the fire!
##### Atmospheric Pressure
« Reply #2 on: 24/05/2007 22:18:54 »
Okay, now what is quickest change that is recorded thus far?  Or is that known?  I know there are many variables to this answer....but just one example would do...

#### another_someone

• Guest
##### Atmospheric Pressure
« Reply #3 on: 25/05/2007 02:57:16 »
Okay, now what is quickest change that is recorded thus far?  Or is that known?  I know there are many variables to this answer....but just one example would do...

If it is recorded, then by inference, it must be known, at least by the person who recorded it (although I accept he may not be aware of the significance of that which he recorded); but as to who it was who recorded such an event, or what was the event he (or she) recorded, I cannot say.

#### moonfire

• Neilep Level Member
• Posts: 4597
• Can't stand the heat, step away from the fire!
##### Atmospheric Pressure
« Reply #4 on: 25/05/2007 05:09:18 »
Of itself, it depends on how and why the drop in sea level.

Atmospheric pressure depends on two factors - the amount of air above your head, and the density of that air.

Simply removing water from the sea, if their is no change in the volume or density of the air, will have no effect on air pressure (i.e. the air will drop in line with the drop in sea level, so the air pressure at sea level will remain the same, although if you live up a mountain, that mountain will have risen in relation to sea level, and so the local air pressure would have dropped slightly at that locality).

If the sea level drops because the water has evaporated, then the water becomes a part of the atmosphere, so you now have more atmosphere above your head (whether that is an increase in density or and increase in volume depends on various factors, although I would normally expect an actual decrease in density, and greater increase in volume).

LOL I did not mean the sea level...geez, I meant with the density of the air...

Hmmm, I was wondering if there was anything that has been recorded...I am going to research something a bit further to find if there are any significant changes noted...thanks Georgie!

#### The Naked Scientists Forum

##### Atmospheric Pressure
« Reply #4 on: 25/05/2007 05:09:18 »