The 2011 magnitude 9 earthquake in Japan was one of the largest earthquakes ever measured. Strong shaking and the consequent tsunami caused the death of nearly 18,000 people.
Strong vibrations in earthquakes can cause soil particles in the ground to jiggle about and lose contact with each other. If there is a lot of water within the ground the shaking causes soil to behave more like a liquid than a solid. This process is called liquefaction.
Footage taken by an American tourist shows dynamic movements of the ground during the Japan earthquake. The changing pressures caused by the soil movement can force water out of the ground and form moving cracks on the surface.
Note that this is not ground movements caused by the actual shaking in the earthquake, but by secondary soil movements.