Comparative planetology: Plate tectonics.

Why don't Venus and Mars have plate tectonics?

Recall subduction:

http://www.personal.psu.edu/users/d/m/dmk262/theory.html

Plate tectonism may require water to weaken the lithosphere -- the rocky upper layer of the planet -- and to make mantle melting easier. Without this easy transformation of subducted material into mantle material, the process of plate tectonics may freeze up.

Back Next

Back to Lecture 18 outline

Back to lectures page

Back to main course page