How much water and atmosphere is there on earth? Cool pic.

[photon]

It depends on where you draw the line. The troposphere is only 8 to 16 km thick, and the stratosphere goes up to 60km.

[octothorp]

Originally Posted by photon

It depends on where you draw the line. The troposphere is only 8 to 16 km thick, and the stratosphere goes up to 60km.

Yeah, not to nitpick but they said atmosphere, which includes the thermosphere, which is measured in the hundreds of kms. Obviously if they choose to just show a quarter of the atmosphere, then they can make a surprisingly small ball, but it's not accurate. My estimate was actually extremely conservative, and one could easily argue that it should be over 20 times the volume of their sphere.

[photon]

Yeah, you could count up to 500km out or more.

[evman150]

I did some very rough back of the envelope calculations and came up with a sphere of radius 800km containing two billion cubic km of water. I used a mean water depth of 5km.

Sounds about right. The 6000 number for the radius of the earth makes the numbers easier and it makes up for the surface area of the land, so they sort of cancel out a bit.

[T@T]

Looks about right, i remember in school that the mass of the atmosphere was roughly twice that of water and water makes up roughly 0.02% of the the earths mass.

[SebC]

If the ball contains all the water, then why are Greenland and the Arctic white?

[RougeUnderoos]

http://chamorrobible.org/images/phot...1025-large.jpg

Cool and somewhat topical photo of the space shuttle taken from the ISS.

[CrusaderPi]

That's not topical at all. Freaking cool though.

[RougeUnderoos]

nm

[RougeUnderoos]

Another one.

http://chamorrobible.org/images/phot...1-19950629.jpg

[Cube Inmate]

I didn't check the assumptions behind those pictures, but if you compressed all of the upper atmosphere into the volume it would occupy at 1 ATM of pressure, then perhaps that's what they're getting at. Obviously that would be much smaller than the actual "volume" of the atmosphere...which is really quite unlimited when you include the expansion at low pressure.

My $0.02.

As for the water, my guess was that the "ball" would be about 1/3 of the size it is....but I was wrong. The oceans are very, very shallow compared with their area. The Pacific is more than 15,000 km wide, and no deeper than 11 km at its lowest point. That's 0.07% ... like someone said, like the skin of an apple.

Originally Posted by octothorp

Yeah, not to nitpick but they said atmosphere, which includes the thermosphere, which is measured in the hundreds of kms. Obviously if they choose to just show a quarter of the atmosphere, then they can make a surprisingly small ball, but it's not accurate. My estimate was actually extremely conservative, and one could easily argue that it should be over 20 times the volume of their sphere.

[Flashpoint]

If all the water on earth is in that little ball, then how come Greenland is covered in snow? Or is ice excluded?

[photon]

Probably just an oversight on whoever made the image.

[SaskaBushFire]

My guess was right on I guessed that exact diameter.

However I just did those calculations in a Geog lab about 2 hours ago