You need to ask yourself whether the sentence makes sense as written. If it doesn't you probably need to change something.
- "Where the great plates of the Earth's crust met, the great stresses and stains cause terrible earth-quakes. Something similar is happen where the earth's major peoples, language, religions and cultures meet. One such area being the eastern end of Mediterranean."
In the first sentence you need to change one word. Tectonic plates don't meet the same way people do, and
met is quite inappropriate in that sentence. You need to change it to
meet. That is because the word as used there means they are in constant contact. In the second sentence,
is happen simply is not used. It has to be either
happens or
is happening. Which do you think is better there? Finally, the sentence fragment at the end should be a part of the second sentence.
:)