As tectonic plates slowly move away from each other, heat from the mantle’s convection currents makes
the crust more plastic and less dense
. The less-dense material rises, often forming a mountain or elevated area of the seafloor. Eventually, the crust cracks.
How does mantle convection affect plate tectonics?
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.
How does mantle convection move plates?
The crust moves because of movements deep inside the earth.
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 .
Does mantle convection drive plate tectonics?
Mantle convection
causes tectonic plates to move around the Earth’s surface
.
What causes convection in the mantle that drives the motion of the plates?
Convection currents within the mantle provide one potential driving force for plate movement. The plastic movement of the mantle material moves like the
flow of mountain glaciers
, carrying the lithospheric plates along as the convection movement in the mantle moves the asthenosphere.
Why is mantle convection 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 does not play a role in convection in the mantle?
The core
does not play an active role in mantle convection. The magnitude of the bottom TBL depends on the cooling rate of the mantle, the pressure and temperature dependence of the physical properties and the radioactivity of the deep mantle.
Who proposed mantle convection theory?
This theory was proposed by
German meteorologist and geologist Alfred Wegener
in 1912 and states that the position of the continents on the Earth’s surface has changed considerably over time.
What is convection current in the mantle?
Convection currents are the movement of fluid as a result of differential heating or convection. In the case of the Earth, convection currents refer to
the motion of molten rock in the mantle as radioactive decay heats up magma
, causing it to rise and driving the global-scale flow of magma.
What drives the plate to move?
The heat from radioactive processes within the planet’s interior
causes the plates to move, sometimes toward and sometimes away from each other. This movement is called plate motion, or tectonic shift.
What is the cooling 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.
What will happen to the convection currents in the mantle?
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.
Which processes are caused by convection currents in the mantle?
Convection currents in Earth are formed due to high temperature of magma (molten rock material) that rises up and colder magma takes its position. This process results in
slab push, volcanic eruptions, and subduction
.
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.
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.
Where does 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
.
