Expert: Ralph Salier-Hellendag - 2/20/2005

Question
how are mountains formed?

Answer
Hi Amber,

Mountians are formed in two ways.

1) Volcanism (Volcanos) where magma or molten rock pushes up from deep below the surface and pushes the rock layers up and out of the way.  And then when the volcano pushes through, it may erupt.  When  this occus, then it begins to build upwards into a cone shaped mountian.  The Hawiian Islands are all volcanic mountians rising from the sea floor!

2) The earth is made up of crustal plates which move. This movement is what we all feel as earthquakes.  As these crustal plates have moved around or into each other, it has caused them to "wrinkel".  These wrinkels are mountians.  For example The Rocky Mountians and the Andes mountians of South America are being pushed up because the North American and South American plates are moving westward into the Pacific Plate.  The force of this movement pushes the crust up and forms the mountians.  This also creates volcanos too.  That is why all around the Pacific there are big earthquake zones and volcanos.  

I hope this helps.  If you have any further questions, please ask.