Tectonic plate interaction boundaries

Illustration of divergent, convergent and transform plates

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Divergent (Mid-Atlantic ridge, The Rift Valley), Convergent (The Andes, The Himalayas) and Transform (San Andreas fault, Dead Sea Transform). There are some sub-varieties but these are the main ones. This makes natural sense, so there’s no remembering to do, when you have two contacting plates: they can either be pushing together, pulling apart or rubbing past each other.

Incidentally, the idea that the giant continents move around all the time, enough to pull apart South America and Africa, and thrust up the Himalayas, obvious as it may seem now, was once not at all obvious. And if you stand on the ground in a big landscape, it’s kind of amazing to think of just what an amazing notion it was to propose.

I read about it in Bill Bryson’s, A Short History of Nearly Everything for which I found a relevant excerpt online - The Earth Moves (pdf) - should you be interested in the characters that had the courage to seriously propose it.

Published 27 May 2015

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What is the potato radius example explained: showing a bumpy potato-like asteroid at the centre of an expanding circle and how it becomes rounder and more planet like as it gets larger

The Potato Radius: When Asteroids Turn Spherical

Leading from Any Chair

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