Convection currents are the result of differential heating . Lighter (less dense), warm material rises while heavier (more dense) cool material sinks. It is this movement that creates circulation patterns known as convection currents in the atmosphere, in water, and in the mantle of Earth.
Why convection currents occur in the Earth’s mantle?
The temperature difference between the upper and lower boundaries of the mantle requires heat transfer to occur. ... While the mantle material remains solid, the heat and pressure allow convection currents to move the mantle material.
What are the three causes of convection currents?
Zack M. convection currents occur when a heated fluid expands, becoming less dense, and rises .
Where do the convection currents occur?
Convection currents in the Earth occur in the mantle . The core of the Earth is extremely hot, and material in the mantle close to the core is heated...
What causes convection to happen and what causes convection cells to form?
Convection Cells
A source of heat is required for a convection cell to form. Fluid is warmed by the heat source and is pushed away. The fluid then begins to lose heat, and inevitably cools. This cooler, denser matter is forced back toward the initial heat source by the flow of newly heated matter.
How are convection currents important to the Earth?
Convections currents in the earth’s mantle are thought to be the driving force of plate tectonics . Where the hot magma is brought near the surface by the convection currents a divergent boundary is created. The divergent boundaries form new oceans and widen existing oceans.
How convection works in the mantle?
The mantle is heated from below (the core), and in areas that are hotter it rises upwards (it is buoyant) , whereas in areas that are cooler it sink down. This results in convection cells in the mantle, and produces horizontal motion of mantle material close to the Earth surface.
What is happening with convection?
rock cools, the density increases , causing the material to sink. What causes the convection cell to turn to the left at point B? lithosphere forcing the convection current to turn left. ... Temperature increases (closer to the core) and density decreases as a result.
How does convection current start?
Convection currents form because a heated fluid expands , becoming less dense. ... As it rises, it pulls cooler fluid down to replace it. This fluid in turn is heated, rises and pulls down more cool fluid. This cycle establishes a circular current that stops only when heat is evenly distributed throughout the fluid.
How do convection occur?
Convection occurs when particles with a lot of heat energy in a liquid or gas move and take the place of particles with less heat energy . Heat energy is transferred from hot places to cooler places by convection. Liquids and gases expand when they are heated. ... The denser cold liquid or gas falls into the warm areas.
What is an example of a convection current?
Convection currents are present in the air– A good example of convection current is the warm air that rises towards the ceiling in your house . The process happens as the warm air is said to be less dense than that of the colder air. Another good example of convection current is wind.
What is the difference between a convection current and a convection cell?
Convection currents are flowing fluid that is moving because there is a temperature or density difference within the material . Because particles within a solid are fixed in place, convection currents are seen only in gases and liquids. ... The cell formed by convection currents is called a convection cell or Bénard cell.
How does air move in convection cells?
When you warm air, it rises. ... Ultimately, the motion leads to a convection cell, with air rising, moving to the side, falling, and moving back . This heat-driven motion of air moves heat around in the atmosphere.
Why does heat rise in a convection cell?
In natural convection (or free convection), a portion of the fluid receives heat from a heat source. This raises the average kinetic energy of the molecules in that portion , which decreases its density. The heated, less dense fluid rises, and cooler, denser fluid from above sinks to replace it.
What is convection and why is it important?
Convection plays an important role in heat transfer inside this pot of water . Once conducted to the inside, heat transfer to other parts of the pot is mostly by convection. The hotter water expands, decreases in density, and rises to transfer heat to other regions of the water, while colder water sinks to the bottom.
How do convection currents move?
Convection currents happen in fluids with a heat source . Hot liquid or gas near the heat source becomes hotter and less dense, so moves upwards. This forces the cooler stuff at the top to move back down. As the hot molecules move up, they cool down and begin to drop.
