Convection currents within the Earth’s mantle are caused by hot material rising upwards, cooling, then dropping back toward the core. … If the interior of the Earth were to cool enough for convection currents to stop, then
the motion of the plates would cease
, and the Earth would become geologically dead.
Why do we need convection currents in the mantle?
Heat rising and falling inside the mantle
creates convection currents generated by radioactive decay in the core. The convection currents move the plates. … The movement of the plates, and the activity inside the Earth, is called plate tectonics . Plate tectonics cause earthquakes and volcanoes .
How does convection affect the Earth’s mantle?
The main heat transfer mechanism in the Earth’s mantle is convection, a thermally driven process where
heating at depth causes material to expand and become less dense, causing it to rise while being replaced by complimentary cool material that sinks
.
What is mantle convection and why is it important?
This flow, called mantle convection, is an important method of heat transport within the Earth. Mantle convection is
the driving mechanism for plate tectonics
, which is the process ultimately responsible for producing earthquakes, mountain ranges, and volcanos on Earth.
What is convection current in the mantle?
Mantle convection is the very slow creeping motion of Earth’s solid silicate mantle caused by convection currents carrying
heat from the interior
to the planet’s surface. … This hot added material cools down by conduction and convection of heat.
What is the process of convection 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.
How mantle convection affects the movement of plates?
Geologists have hypothesized that the movement of tectonic plates is related to convection currents in the earth’s mantle. …
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.
Why is the mantle the thickest layer?
Below the crust is the mantle, a dense, hot layer of semi-solid rock approximately 2,900 km thick. The mantle, which contains more iron, magnesium, and calcium than the crust, is
hotter and denser because temperature and pressure inside the Earth increase with depth
.
What will happen to the convection currents in the mantle of Earth’s interior eventually cools down?
Explanation: Convection currents within the Earth’s mantle are caused by hot material rising upwards, cooling, then dropping back toward the core. … If the interior of the Earth were to cool enough for convection currents to stop, then
the motion of the plates would cease, and the Earth would become geologically dead
.
What is Earth’s densest layer?
The densest layer (
inner core
) is at the center and the least dense layer (crust) is the outermost layer. The atmosphere, composed of gases, can technically be considered a layer as well and is obviously lighter than the crust.
What are the two primary drivers of mantle convection?
Since convection in the Earth’s mantle is driven both from below (by heat from the core) and from
within (by radiogenic heating)
, the Rayleigh number for mantle convection should ideally combine both the above forms.
What is the main reason why convection currents occur?
convection currents occur when
a heated fluid expands, becoming less dense, and rises
. The fluid then cools and contracts, becoming more dense, and sinks.
How fast do convection currents in the mantle move?
Estimates of the speed with which Earth’s mantle moves range from
1 to 20 cm/year with an average of about 5 cm/year in the case of plate motions
to as much as 50 cm/year in hotspots such as the Hawaiian Islands (see Plates, Plumes, And Paradigms (2005) edited by Gillian R. Foulger, James H.
Where does heat come from that drives this convection current in the mantle?
Question One: Where does the heat come from that drives this convection current in the mantle? The heat driving the convection current in the mantle comes from
the extreme temperature in the earth’s core, and the heat from the mantle itself
.
What is the evidence for mantle convection and what is the mechanism that causes it?
It has long been known that throughout the mantle there are convection currents circulating,
caused by the difference in temperature at the earth’s interior and surface
. Hot material from the earth’s outer core rises very slowly (over millions of years) throughout the mantle.
What is the heat source for convection in the mantle?
The primary sources of thermal energy for mantle convection are three: (1)
internal heating due to the decay of the radioactive isotopes of uranium, thorium, and potassium
; (2) the long-term secular cooling of the earth; and (3) heat from the core.
