Geological aspect of mountains?

**Luke987** · Aug19-07, 06:25 PM

A few days ago I heard that if mountains, really a result of plate tectonics, didn't exist our planet would only be covered by a few thousand feet of water and that it would have a perfect geode form.

How true is this? Scientifically have they been given a purpose?

(Not interested in philosophy here)

Thanks

**Evo** · Aug19-07, 07:07 PM

Originally Posted by Luke987

A few days ago I heard that if mountains, really a result of plate tectonics, didn't exist our planet would only be covered by a few thousand feet of water and that it would have a perfect geode form.

How true is this? Scientifically have they been given a purpose?

(Not interested in philosophy here)

Thanks

They create weather patterns for one thing.

**mgb_phys** · Aug19-07, 08:33 PM

If you smoothed out the surface, it would be under water. Basically the oceans are on average much deeper than the land is high.

As to the purpose of mountains - other than for planes to crash into and singing nuns to run accross I don't know.

**Astronuc** · Aug19-07, 08:38 PM

Well conceivably all the solid mass could form a uniform sphere and the water form an outer layer, it being less dense.

But Nature seemed to have other ideas.

Here are some ideas of what the Western US looked like at different periods.
http://jan.ucc.nau.edu/~rcb7/paleogeogwus.html

Somewhere there is a site that maps ancient oceans, which indicates that water covered more of the earth's surface in the past than now. The ocean's were much shallowe as well. But at the moment, I don't remember the site.

Here's one but it's not the one I'm thinking of.
http://www.palaeos.com/Proterozoic/Proterozoic.htm
http://www.palaeos.com/Paleozoic/Paleozoic.htm

**Astronuc** · Aug19-07, 08:40 PM

Originally Posted by mgb_phys

As to the purpose of mountains - other than for planes to crash into and singing nuns to run accross I don't know.

or serving as a backdrop to the sound of music.

**Luke987** · Aug19-07, 08:59 PM

Thanks for the quick replies.

So is it safe to say that there would be no real problem if mountains weren't on Earth? Would it have been a problem back in Homo sapiens periods etc when they had no idea on how to make sea water drinkable or the like? I don't see it leading to extinction.

All other posts appreciated.

Evo, can you expand on the weather patterns? Thanks :)

**mgb_phys** · Aug19-07, 09:09 PM

Originally Posted by Luke987

So is it safe to say that there would be no real problem if mountains weren't on Earth?

For anything that lives in deep oceans it wouldn't really matter.

Would it have been a problem back in Homo sapiens periods etc when they had no idea on how to make sea water drinkable or the like? I don't see it leading to extinction.

It would have been difficult to get H.S. when there was no land for fish to crawl out onto and begin the process of evolving into reptiles and then mammals.

Remember if there were no mammals the surface would ALL be ocean a few 1000 feet deep!

**Evo** · Aug19-07, 09:20 PM

Originally Posted by mgb_phys

As to the purpose of mountains - other than for planes to crash into and singing nuns to run accross I don't know.

Uhm, CLIMATE. WEATHER.

http://www.bbc.co.uk/weather/feature...ountains.shtml

http://www.ace.mmu.ac.uk/eae/Climate...Mountains.html

http://www.sciencedaily.com/releases...1018075220.htm

**DaveC426913** · Aug19-07, 10:03 PM

I imagine if we didn't have mountains, the weasther would be a fair bit more harsh though more consistent.

You could get high velocity winds and very powerful hurricanes unfettered by the weakening effect of landmasses.

**Luke987** · Aug20-07, 03:15 PM

Originally Posted by DaveC426913

I imagine if we didn't have mountains, the weasther would be a fair bit more harsh though more consistent.

You could get high velocity winds and very powerful hurricanes unfettered by the weakening effect of landmasses.

Though would you say more consistent weather would make up for that and thus no mountains would be good?

**DaveC426913** · Aug20-07, 03:45 PM

Originally Posted by Luke987

Though would you say more consistent weather would make up for that and thus no mountains would be good?

I am merely stating effects, not judging them.

Perhaps I shouldn't have tied harsh and consistent together like that. Though I think it would have been even weirder to say more harsh and more consistent.

**Evo** · Aug20-07, 03:51 PM

The weather in the plains is caused by air around and down the rockies.

http://www.sciencedaily.com/releases...0615174218.htm

**Luke987** · Aug20-07, 09:26 PM

Interesting stuff.

**billiards** · Aug28-07, 08:40 AM

It's all party of the rock cycle mate, mountains = uplifted rock, you get basins behind the overiding tectonic slab (hinterland) and in front of it (foreland), the mountains erode and the sediment is deposited in the basins. So if you didn't have mountains these basin sediments wouldn't form, basically the earth's geology would be completely different, that's not the "purpose" of mountains, the purpose of mountains is so we can go rock climbing :). Mountains do provide geologists with a lot of rock exposure, without mountains most of the earth's surface would be covered with water and soils (although maybe without mountains there wouldn't be life, and thus no soils?) - without mountains most people wouldn't even know what a rock was!

**PJS** · Aug8-08, 07:33 PM

Mountains are important for a couple of reasons:

1) They usually are the source for rivers that provide a water source to human populations.
2) They create a cooling off spot for precipitation. As the clouds move over the mountains, the air cools and finally produces rain which helps the agriculture for human populations.