What are tsunamis? What might cause a tsunami to happen? Are there any signs for tsunamis out there that could warn out people? There are lots and lots of tsunami facts for kids which could teach them more about this natural disaster. What actually is a tsunami? Tsunami is a large ocean wave that is caused by underwater earthquake volcanic explosion. A lot of people think that tsunamis are tidal waves but they are not because tidal waves are caused by the forces of the sun, moon and planet tides, as well as the wind as it moves over the water with typical waves, water flows in circles. This is different with a tsunami because in the case of tsunamis, water flows straight and that is why they cause so much damage. How is the tsunami formed? That’s part of understanding tsunamis and knowing why they are formed, how and what are the consequences that they might cause. Tsunamis are formed when something called tectonic plates in the earth’s crust are formed, they are usually referred to as crying together and sometimes these plates get stuck and the pressure gets up and soon they slam into a new position which eventually causes an earthquake that is the main reason behind tsunamis.