Mars maar craters explosive style formation gravitational effect
I recently saw a video lecture given that went through a calculation of how the size of volcanoes is related to the mass of a planet.  I don't remember the details or the math but the conclusion was that the smaller the planet the bigger the volcano.  This explains why Olympus Mons on Mars is so much bigger than anything on earth.  I can find a link to the lecture if that will help.  The equations are given in the lecture.