In flocabulary The liquid mantle is constantly churning in movements called convection currents. Convection is a method of heat transfer in which hot liquid rises and cooler liquid sinks in a continuous cycle. The large pieces of Earth’s crust are always moving above the mantle. People cannot feel these movements because they are very slow. They move at about the speed that fingernails grow, or a couple of inches per year. Over long periods of time, convection currents create cracks in the Earth’s tectonic plates. These cracks are called faults. witch one is correct
A it is solid and does not move
B It moves quickly and unpredictably.
C It moves in very slow currents
D It can suddenly cause huge fault lines