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All of Earth's water in a single sphere (2019)

usgs.gov

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Re: All of Earth's water in a single sphere (2019)

#151

Post by aspectmin »

RIMR wrote: post #123
sfink wrote: post #59

I long assumed that the Earth is a "water planet" because water is mostly what you see from a distance. It wasn't until I did the math that I realized that is really about wet rocks in space vs dry rocks in space. Earth isn't made of water, it's just a damp rock. Or a bowling ball that you squirted a dozen times with a spray bottle.

The ballpark math is easy to do in your head too. The diameter of Earth is 8,000 miles, and the deepest point in the ocean, the Mariana Trench, is only 7 miles deep. It's immediately apparent that the oceans are tiny by comparison to the rest of the mass that is Earth.

An interesting exercise is to do this exact same calculation with the atmosphere.

Re: All of Earth's water in a single sphere (2019)

#152

Post by mistercow »

I think it’s important to keep in mind that if you did this same visualization on a planet with ten times Earth’s radius, but the same ocean depth and water distribution, then the water blobs would seem even smaller in comparison to the planet.

I’m just not sure it’s a particularly useful illustration to compare the volume of water on a planet to that of the planet itself.

Re: All of Earth's water in a single sphere (2019)

#153

Post by rising-sky »

digging wrote: post #136
rising-sky wrote: post #120

Earlier quoted context omitted.

I'm aware, notice my comment specifically states "the Earth's *surface* " not just "the Earth". However, my kitchen counter is a flat surface, it's common knowledge the Earth isn't flat and the average ocean depth is 3,682 meters

That was my point. The Earth isn't flat, but its surface is very smooth. You give the average ocean depth at 3.7km, but the Earth's diameter is about 12,742km, making those bumps pretty insignificant. If you cover your countertop in sandpaper and spill water on it, the difference in coverage going to be almost negligible.

Yea, just to be clear, I'm not disputing the image at all, my original comment is only an observation on the stark contrast when you juxtapose those two representations

Re: All of Earth's water in a single sphere (2019)

#155

Post by tejohnso »

RIMR wrote: post #123
sfink wrote: post #59

I long assumed that the Earth is a "water planet" because water is mostly what you see from a distance. It wasn't until I did the math that I realized that is really about wet rocks in space vs dry rocks in space. Earth isn't made of water, it's just a damp rock. Or a bowling ball that you squirted a dozen times with a spray bottle.

The ballpark math is easy to do in your head too. The diameter of Earth is 8,000 miles, and the deepest point in the ocean, the Mariana Trench, is only 7 miles deep. It's immediately apparent that the oceans are tiny by comparison to the rest of the mass that is Earth.

Neil DeGrasse Tyson says the earth scaled down to the size of a billiard ball would be smoother than any billiard ball ever made.

Re: All of Earth's water in a single sphere (2019)

#156

Post by dredmorbius »

umvi wrote: post #16

> This sphere includes all of the water in the oceans, ice caps, lakes, rivers, groundwater, atmospheric water, and even the water in you, your dog, and your tomato plant. Does it include water in the mantle? ( https://www.bnl.gov/newsroom/news.php?a=111648 ) or other non-liquid water for that matter like hydrates (ebsom salts, etc)

Given that the quantity of water in the mantle is thought to be equivalent to that in all the oceans (large drop), I'd presume not.

The mantle-water research is fairly new, with this report from 2017:

"There’s as much water in Earth’s mantle as in all the oceans"

https://www.newscientist.com/article/2133963-theres-as-much-...>

The USGS detail pages are based on a 1993 publication, Igor Shiklomanov's chapter "World fresh water resources" in Peter H. Gleick (editor), Water in Crisis: A Guide to the World's Fresh Water Resources (Oxford University Press, New York).

https://www.usgs.gov/special-topics/water-science-school/sci...> and https://www.usgs.gov/special-topics/water-science-school/sci...>

Re: All of Earth's water in a single sphere (2019)

#157

Post by mikewarot »

It looks too small, perhaps there's more water tied up in the core and mantle than that?

[1] https://www.bnl.gov/newsroom/news.php?a=111648

[2] https://www.space.com/water-in-earth-core-forms-crystal-laye...

[3] https://www.goethe-university-frankfurt.de/125691203/An_ocea...

Re: All of Earth's water in a single sphere (2019)

#158

Post by dredmorbius »

Pat_Murph wrote: post #77
umvi wrote: post #16

> This sphere includes all of the water in the oceans, ice caps, lakes, rivers, groundwater, atmospheric water, and even the water in you, your dog, and your tomato plant. Does it include water in the mantle? ( https://www.bnl.gov/newsroom/news.php?a=111648 ) or other non-liquid water for that matter like hydrates (ebsom salts, etc)

The wording of the legend description says all the war in, on and above the earth so we have to assume that is does take it into account.

Sources say otherwise, see my immediate prior comment.

Re: All of Earth's water in a single sphere (2019)

#159

Post by dredmorbius »

NB: The infographic and articles are based on a 1993 publication.

More recent research, from about 2017, suggests that there's about as much water in Earth's mantle as in all the oceans, so we either need another drop roughly the volume of the first, or the second drop should be greatly expanded.

See: "There’s as much water in Earth’s mantle as in all the oceans" (2017) https://www.newscientist.com/article/2133963-theres-as-much-...>

The USGS is citing a 1993 publication, Igor Shiklomanov's chapter "World fresh water resources" in Peter H. Gleick (editor), Water in Crisis: A Guide to the World's Fresh Water Resources (Oxford University Press, New York) (see the detail links from the submitted article).

That said, water remains a precious resource, and fresh surface water all the more so.

Edit: /double the size/s/size/volume/ above, for clarity.

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