Earth's materials move through various cycles. The hydrologic cycle involves the movement of water between reservoirs like oceans, glaciers, groundwater and atmosphere through processes like evaporation and precipitation. The atmospheric cycle moves air between reservoirs powered by the sun's heating through convection. Chemical elements also cycle through the oceans and atmosphere. Rocks cycle between igneous, sedimentary and metamorphic forms through melting, weathering and burial. All of Earth's cycles are interconnected and influence one another over various timescales.