1. Too much force, Two powerful people or just one or more can emit a huge amount of force like if two highly powerful people clashed fists which could make a Shattering Ryft, you've probably seen this in one of Neat's stories
2. Too much Energy, When two high forces of energy collide then if it is powerful enough it can cause a Shattering Ryft you've probably also seen this one in One of Neat's stories