When the convection currents flow in the mantle they also move the crust. The crust moves because of movements deep inside the earth. Convection currents in Earth's mantle are caused by the rise of hot material rising towards the crust, becoming cooler and sinking back down. This is mostly true. The core's heat energy is transferred to the mantle, causing it to rise towards the Earth's surface, which is cooler. The crust floats with these currents. Although the colored liquids that mix are more interesting to watch, the other set of warm and cold water bottles helps to illustrate an important phenomenon that can occur in the atmosphere in cooler months. The movement of the currents plays a factor in the movement of the mantle. Convection currents are caused by the very hot material at the deepest part of the mantle rising, then cooling, sinking again and then heating, rising and repeating the cycle over and over. It isn’t perfectly uniform, though; watch a Lava Lamp for a while and you’ll see the unpredictable convection currents in action. The rock is in a semi-liquid state and should behave like any other fluid, rising up from the bottom of the mantle after becoming hotter and less dense from the heat of the earth’s core.
Convection Currents in the Mantle- Videos, Worksheets AND a Lab!

View a moving model of convection currents in Earth’s mantle. You will learn about the theory of plate tectonics in another lesson, however, it is important for you to understand how convection currents operate in the mantle. The theory of mantle convection says that a layer of the earth 1,800 miles (3,000km) thick is doing exactly that: responding to heat from the molten core below, moving upward, then cooling and sinking back down. Third from the top in a series of ten animations depicting mantle convection; produced by Michael Gurnis' group at Caltech. Convection currents are the movement of fluid as a result of differential heating or convection.

In the case of the Earth, convection currents refer to the motion of molten rock in the mantle as radioactive decay heats up magma, causing it to rise and driving the global-scale flow of magma. All the heat from “melting Earth” now drives the convection currents that are responsible for geological processes today. The activity below will focus on convection in the mantle. This process occurs repeatedly, causing the currents to constantly flow. Convection in Earth’s Mantle. Geologists believe the molten rock deep within the earth circulates by convection currents. What Causes Convection Currents in the Earth's Mantle?
This video is from a BBC documentary film titled Earth: The Power Of The Planet. The videos below show convection currents … Diverging currents pull them apart. Animation of a proposed mechanism of superplume generation at the core/mantle boundary (succinct explanation included).