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Author Topic: Why are the majority of the Earth's landmasses asymmetrically distributed?  (Read 1631 times)

Offline eternity

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If the whole planet is active with plate tectonics, volcanic action etc. why have all of the earths land masses tended to be one one side of the planet?
« Last Edit: 23/03/2014 23:17:54 by chris »


 

Offline evan_au

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Re: landmasses
« Reply #1 on: 21/03/2014 10:53:07 »
Geologists believe that Earth's continents are rather spread out, at present.

They believe that in the past, all of the continents were combined into a large Supercontinent "Pangaea" (Greek for "All Earth").

Some geologists, examining deeper rock strata, believe that Pangaea formed after the breakup of an even earlier supercontinent.

Earthquake waves suggest that Earth's mantle is a hot viscous rock, with convection cells which tug on the crustal rocks, moving them around. These dynamic convection cells are likely to sometimes separate continents, and sometimes push them together.
 

Offline eternity

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Re: landmasses
« Reply #2 on: 21/03/2014 13:31:08 »
Thank you very much for your reply.

I agree that the land masses are much more spread out (of course! - its a fact! you say). I had noticed something unusual which lead to me asking the O.P.

I downloaded an application. On it, is shown the various super continents forming and moving apart until our recognisable continents are formed (its a fantastic app. by the way!).

I noticed if you pointed the earth in a certain direction, there would always be water in that area approximately between 360 MYA and now (Honolulu is floating about from left to right/up and down but thats about it - the rest is water). The Americas only start to creep over 30 MYA but then only cover a very small percentage, the rest is the modern day Pacific Ocean which remains almost the same until present day.

It just seemed very strange after as you pointed out, the earths crust is constantly moving.

Thanks
« Last Edit: 21/03/2014 14:28:34 by eternity »
 

The Naked Scientists Forum

Re: landmasses
« Reply #2 on: 21/03/2014 13:31:08 »

 

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