What caused the interior of earth to separate into layers?

What is the general rule about surface currents? cold water flows along the ocean floor towards the equator. the east coasts of continents have cold surface currents, and the west coasts of continents have warm surface currents. seasonal and constant offshore winds create significant upwelling along the west coasts of south and north america and africa. the west coasts of continents have cold surface currents, and the east coasts of continents have warm surface currents.

The oldest seafloor in the atlantic ocean is located closest to the edge of the continents. explain how this age can be used to figure out when north america first began to separate from europe

Which two nations are doing the most to combat their environmental issues?