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How long have convection currents been occurring in the mantle?
Wiki User
∙ 10y ago
14 billion years
Wiki User
∙ 10y ago
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What is a Athensphere?
The Athensphere is not a layer in the Earth. The asthenosphere is the region of the mantle that is capable of moving by convection and has been linked to the movement of the tectonic plates (the lithosphere).
Which type of heat transfer sets up currents in fluids?
The current in the fluid is the result of a difference in temperature at different depths.It's called convection, and it does the transferring of heat from the bottom to the topof the fluid.What sets up the convection currents is whatever it was that added heat to thebottom of it. That could have been conduction, radiation, or a chemical process.
Why do plates separates from each other?
From the creation of crust by magma at divergent plate boundaries. It has been proposed that when the above crust is created, it creates in the form of an upward pointing wedge of basalt and this wedge forces the plates apart. For a more extensive discussion of this proposal see http://members.tripod.com/~charles_W/ridge.html
When did the first blizzard occur?
Blizzards have been occurring longer than people have been around.
When did tornadoes first happen in WA?
It is impossible to say; tornadoes have been occurring there since before anyone was around to record them. It is likely they have been occurring there since the land that would become Washington first formed.
How has earthquake data been used to explore the size of convection currents in the mantle?
earthquake data is used to explore the structure of the mantle
What is true about convection in Earth's mantle and tectonic plate motion?
Within the earth's mantle, which is semi-molten, there are convection currents caused by differences in temperature. These currents apply force from beneath to the plates of the earth's crust. The plates move slightly, which causes the very slow change in the shapes of our continents and oceans (and also causes occasional earthquakes).All of this is true about convection currents, however there is significant dispute as to whether the tectonic plates are actually moved by convection currents. It could equally be true that "There are no convection currents in the Earth's mantle". Although is is the best theory going, there has been insufficient evidence that these currents actually exist. Alternative theories include:Continental drag: As a plate is subducted beneath another, the weight of the sinking end pulls the rest of the plate with it. This causes continental drift. The biggest flaw is that not all plates even have destructive boundaries.Hotspots: Hotspots themselves are responsible for continental drift (a similar sort of idea to convection currents, but we do know that hotspots exist). The biggest flaw is that not all plates have a hotspot on them.
Which has not been proposed as a mechanism of plate motions?
The idea that plate motions are caused by electromagnetic forces has not been widely proposed as a mechanism of plate motions. The most accepted mechanism is the theory of plate tectonics, which suggests that plate motions result from the movement of convection currents in the Earth's mantle. Other proposed mechanisms include ridge push, slab pull, and mantle plumes.
Where was the continental drift?
Continental drift occurs under the earths crust by convection currents in the mantle which drives the plates. It has been happening since the development of the earths core and is happening now and until the end of the earth.
How long have convection currents been moving the Earth's surface?
Approximately 3 billion (3,000,000,000) years
What is the role of gravity in creating convection currents?
Gravity causes the convection currents. Without gravity, convection would have been completely backwards. Gravity pushes the cold air down and stops the warm air going up.
What is a Athensphere?
The Athensphere is not a layer in the Earth. The asthenosphere is the region of the mantle that is capable of moving by convection and has been linked to the movement of the tectonic plates (the lithosphere).
Which type of heat transfer sets up currents in fluids?
The current in the fluid is the result of a difference in temperature at different depths.It's called convection, and it does the transferring of heat from the bottom to the topof the fluid.What sets up the convection currents is whatever it was that added heat to thebottom of it. That could have been conduction, radiation, or a chemical process.
Without convection currents what would happen?
THE WORLD WOULD END. that is all. well not really. THISis what would happen if it were to BLOW UP and the convection currents had died. Really, the water would disappear, we wouldn't have volcanoes or earthquakes, there would be NO LIFE AT ALL WHATSOEVER, there would be NO WIND, and we'd all be dead. sadly.
How is it possible for mantle rock to flow?
Mantle rock is composed of a type of igneous rock peridotite which has a high iron and magnesium content. This rock is so hard and dense that it is not able to flow like a liquid. However due to the high temperatures and pressures that are present in the mantle it is possible for mantle rock to flow like a plastic-like material. This process is called "plastic deformation". Plastic deformation occurs when temperatures and pressures are high enough to cause the atoms in the rock to rearrange themselves. This rearrangement allows the rock to become more malleable and it is able to bend and flow like a liquid. This process is responsible for many of the changes that occur in the mantle such as convection currents and plate tectonics. The process of plastic deformation is not easily observed as it occurs deep within the Earth. However scientists have been able to determine the amount of pressure and temperature necessary to cause plastic deformation in mantle rock. It is estimated that temperatures must be at least 2000 degrees Celsius and pressures must be at least 10000 times the atmospheric pressure at sea level in order for mantle rock to flow. In summary mantle rock is composed of peridotite a type of igneous rock that is so hard and dense that it is not able to flow like a liquid. However due to the high temperatures and pressures that are present in the mantle it is possible for mantle rock to flow like a plastic-like material through a process called "plastic deformation". This process is responsible for many of the changes that occur in the mantle such as convection currents and plate tectonics. Temperatures must be at least 2000 degrees Celsius and pressures must be at least 10000 times the atmospheric pressure at sea level in order for mantle rock to flow.
What mechanism did Alfred Wegener propose for continental drift?
He predicted that convection currents within the earth's mantle are driven by radioactive heat might furnish the mechanism for the continental drift theory. -Lochie O'Brien and Jaidyn Tilbrook
Which is convection of the Earth's mantle most directly related?
tectonic plate motionAs a result these test have been tested mostly in the hottest continent Africa, by African scientist and more which the hottest country is Djibouti," another Somali speaking country in Eastern Africa.
