How thin is the air at cotapaxi??

[Jules]

So the question that arose whilstwe were trecking up volcanoes in Equador is this.

When you are at altitude it's really hard to breath because the air is thinner. it feels like it 's got no oxygen in it.

When you are 4800m above sea level what is the density of air relative to the air at sea level? and what would the PPO2 be? cos it feels really horrid.

I think I recall that you need something like 16% as the threshold of oxygen in air to susstain life so how close is it and at what altitude would the air become unable to sustain you?

I know it's not diving physics but it's climbing physics and Super really needs to know.

Jules

[Jules]

I am sort of assuming that the percentage would still be 21% but there is just a lot less molecules of all the gases in a lungful due to the lower density.

but how much lower is it? feels like you got an elephant sitting on your chest!

[GLOC]

Standard atmosphere is 1013.2mb at sea level and that level drops at 1millibar per 30ft or 10m so you can work it out yourself

700 millibars equates to approximately 10 000ft and 500 millibars at 18 000ft

[al kennedy]

density at 5000m is 0.74 kg/m3, and pressure 540 mB.

if i'm right, i think that gives a PPO2 of 0.11.

[mala]

Originally Posted by al kennedy

density at 5000m is 0.74 kg/m3, and pressure 540 mB.

if i'm right, i think that gives a PPO2 of 0.11.

the low pp means that gasses tend to absorb slowly into the tissues and bloodstream.
you can get knackered chewing a mars bar.

[Jules]

Originally Posted by al kennedy

density at 5000m is 0.74 kg/m3, and pressure 540 mB.

if i'm right, i think that gives a PPO2 of 0.11.

but wouldn't you be dead if the ppo2 was only 0.11?

[mala]

Originally Posted by Jules

but wouldn't you be dead if the ppo2 was only 0.11?

not if you dont move.

[macstinator]

http://www.acgih.org/tlv/AIHce_Slides_4.pdf

All you need to know.

[jamesp]

I recently(monday) had a BSAC nitrox instructor telling me that 13/30 trimix was hypoxic(give the man a biccy) and that any attempt to breathe that mixture at the surface would immeadiately render me unconcious! 10/50 meant I would be dead.
OK so the big yellow blender looks after things and I avoid any severe activity like surface swims...

But I have Skiied at over 3000M, and I dont recall taking it easy. Checking the link I was about on track with my maths, I`ve flogged my guts out at an equivalent of 13%O2, without rendering myself unconcious; more than once.

QED

He was talking bolloks.

Sort off!

[mala]

altitude is a funny thing.
i took a single tiger to 14000 feet and felt fine for about 5 mins.
next time i saw the alt it said 10000.

mmmm....

life and stuff.