Convection occurs through the movement of particles. As particles become heated, the molecules move faster and faster, and as molecules move apart, density decreases. The warmer, less dense material rises compared to the surrounding cooler, higher density material.

During convection, cooler water or air sinks, and warmer water or air rises. This movement causes currents. These currents move water all around the earth, bringing warm water to cooler areas and vice versa. This redistributes thermal energy and causes changes in the weather.

The heating of the Earth’s surface and atmosphere by the sun drives convection within the atmosphere and ocean. This convection produces winds and ocean currents. The greater the pressure differences between a low-pressure area and a high-pressure area, the stronger the winds.

Convection currents describe the rising, spread, and sinking of gas, liquid, or molten material caused by the application of heat. Tremendous heat and pressure within the earth cause the hot magma to flow in convection currents. These currents cause the movement of the tectonic plates that make up the earth’s crust.

What happens to convection currents when a fluid reaches a constant temperature? When a fluid reaches a constant temperature, no one part of the liquid is hotter than the other. Therefore, no rising occurs and convection currents stop.

What happens after the heat source is removed? Without heat, the convection currents will eventually stop when all of the material has reached the same temperature. The heat source for these currents is heat from Earth’s core and from the mantle itself.