Question

1. one theory about how plate tectonics occur is called ridge push. to what does this refer?

a force causing plates to move away as new magma rises up and forms new ocean crust
a force causing plates to enter the mantle at the mid - ocean ridge
a force that rips plates apart and causes rock to return to the mantle
a force causing plates to collide with each other at the mid - ocean ridge

Explanation:

Ridge push is a tectonic force where new magma rises at mid-ocean ridges, creating new oceanic crust. This new, warm crust sits higher than the older, denser crust, and the gravitational pull on this elevated crust drives the tectonic plates to move away from the ridge. The other options are incorrect: plates do not enter the mantle at mid-ocean ridges (that occurs at subduction zones), ridge push does not rip plates apart to return rock to the mantle, and plates do not collide at mid-ocean ridges (collisions happen at convergent boundaries).

Answer:

a force causing plates to move away as new magma rises up and forms new ocean crust