 Since the ice will bend slightly when any vehicle capable of travelling on ice-covered water, it follows that travelling at some critical speed may impose sufficient flexing of the ice sheet to cause resonance, and this may result in positive feedback effectively amplifying the oscillation within the body of water supporting the ice beneath the vehicle.These are three-dimensional oscillations of forces which occur within a disturbed liquid and are usually observed as surface waves.There have been cases of destruction of ice by flexural gravity waves (FGW) produced by moving cars, trains on railway crossings, aircraft during takeoff and landing, etc.