earthquake, any sudden shaking of the ground caused by the passage of seismic waves through Earth’s rocks. Seismic waves are produced when some form of energy stored in Earth’s crust is suddenly released, usually when masses of rock straining against one another suddenly fracture and “slip.”
People jumping up and down, fit that definition, and they actually specify that it’s not “just” masses of rock (tectonic plates)
TYL, you are welcome, go read some books and “touch grass”.