This PDF of the Earth's crust, while informative, confuses me a bit now because it appears to misrepresent facts, namely that if the Earth's core is mostly iron and nickel I would expect there to be more than traces of these elements. And if we have so much water (H2O) I would expect there to be higher than 0.15% of Hydrogen, unless we're not counting water as part of the Earth's crust. Also, what about the Earth's atmosphere?
I'm thinking this view is too narrow-minded and puts things out of perspective.

Question

This PDF of the Earth's crust, while informative, confuses me a bit now because it appears to misrepresent facts, namely that if the Earth's core is mostly iron and nickel I would expect there to be more than traces of these elements. And if we have so much water (H2O) I would expect there to be higher than 0.15% of Hydrogen, unless we're not counting water as part of the Earth's crust. Also, what about the Earth's atmosphere? 
I'm thinking this view is too narrow-minded and puts things out of perspective.

Accepted Answer

I think the key here is that the infographic is talking about the elements that compose the Earth's crust, which doesn't include the water on top of the crust, or the atmosphere above it. It's not a misrepresentation; it just has a particular focus. As for nickel and iron, you're right that the core is mostly nickel and iron, but that's because these very dense elements sank to the center of the Earth while the entire planet was still molten--leaving much less near the surface of the Earth to go into the crust.

Big History Project

Course: Big History Project > Unit 4

ACTIVITY: Infographic — Chemical Abundances: Earth’s Crust

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