Does the weight of all the people, homes, and cars in California have anything to do with the earthquake activity that they have there?

Answer 1

Favourite answer

Sure, but it's a tiny amount.

More important is water and oil drilling, geothermal draw, and plate tectonics.

Answer 2

No. California was having lots of earthquakes long before there were so many people and infrastructure  there. 

Answer 3

The earthquake activity in California is due to the number of seismic faults in California.