The force that people feel when two plates jerk into a new position is the earthquake. An earthquake, which is also referred to as tremor, quake, or temblor, is an act whereby the surface of the earth shakes due to a release of energy that seems sudden on the lithosphere of the earth, which creates seismic waves.
There are ranges of earthquakes. Some can actually be so weak that they will not even be felt, while some can be so strong that they can move a great landmass, and even turn a while city upside-down. The type, size, and frequency of earthquakes that are experienced over over a specific period of time is the seismic activity or seismicity of an area.
There is relatively always shaking and disruption of the solid ground when earthquake activity is taking place. Earthquakes, sometimes, can trigger landslides and volcanic activity occasionally.