4. What is the name of the long mountain range that runs down the west coast of South America? Name the countries that have some of this mountain range within their borders.

Geothermic gradient is the rate of increasing temperature with respect to increasing the depth in the earths interior. away from tech tonic plates boundaries, it is about 25-40 c/km (72-87 degrees f/mi) of depth near the surface in most of the world.