The divergent boundaries form new oceans and widen existing oceans. Tremendous heat and pressure within the earth cause the hot magma to flow in convection currents. Convection currents occur within: the geosphere — plate tectonics. 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. Natural convection, or free convection, occurs due to temperature differences which affect the density, and thus relative buoyancy, of the fluid. Heavier denser components will fall, while lighter less dense components rise, leading to bulk fluid movement. Convection, process by which heat is transferred by movement of a heated fluid such as air or water. Natural convection results from the tendency of most fluids to expand when heated—i.
Everyday Examples of Convection radiator — A radiator puts warm air out at the top and draws in cooler air at the bottom. Convection is the movement of heat because of the movement of warm matter.
For example, atmospheric circulation moves warm air to cool places, causing wind. Wind, in turn, can enter and cool a room if the window is open. A convection current is a process that involves the movement of energy from one place to another.
It is also called convection heat transfer. The convection currents tend to move a fluid or gas particles from one place to another. Answer: The main cause of global convection currents is the uneven heating of the earth by the sun. While merely placing the beaker on the hot plate and heating it would cause convection to occur, it is likely that many convection currents would form in different directions, and they would be difficult for students to observe.
To ensure that convection currents will flow mainly in one preferred direction, and one that will make them visible to the class, we place two pads between the hot plate and the beaker. On the left is an insulating pad, and on the right is a section of copper plate. This maintains heat flow from the hot plate to the beaker on the right side, and inhibits it on the left side.
The convection current thus begins at the bottom of the right side of the beaker, where the heated fluid rises. The fluid continues up the right side of the beaker, cooling along the way. When it begins to sink, it is pushed to the left side by the fluid rising along the right. After a few minutes, one can see a convection loop. Water vapor in the rising air condenses as the air cools at higher altitudes and can form towering cumulonimbus clouds that produce thunderstorms.
The subsequent movement of air back toward the equator is responsible for the trade winds. This phenomenon is responsible for earthquakes and volcanic activity. An existing plate, propelled by convection currents below, can push into another plate, building mountain ranges such as the Himalayas.
Convection cells also exist in the sun.
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