Ms Kaur, U r only partially right. Tectonic plates r floating on molten lava, which is at the core of the earth. When man makes massive structurs on earth like dams( huge dam itself and accumulated water), clusters of high rise buildings in a seismoligically very active zone then that weight imbalance increases probability of quake. So it is very risk to carry out such activities near seismic fault lines or where thickness of tectonic plate is less... example terhai region of india, assam.
