How does heat and gravity cause tectonic plates to move?

Cooler water sinks to the bottom. Earth’s solid crust acts as a heat insulator for the hot interior of the planet. 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 density affect plate tectonics?

When two plates come in contact with each other through plate tectonics, scientists can use the density of the plates to predict what will happen. Whichever plate is more dense will sink, and the less dense plate will float over it. The exact result depends on which types of plates are interacting.

Why is water important for plate tectonics?

Water plays a crucial role in plate tectonics by easing the brittle and ductile deformation of the Earth’s lithosphere. Water lowers the Mohr-Coulomb for brittle fractures. During ductile deformation, it lubricates different deformational regimes. This is also important for the deformation in the asthenosphere.

What role does the asthenosphere play in plate tectonics?

The asthenosphere is thought to play a critical role in the movement of Earth’s tectonic plates. The collision, lateral sliding, and separation of plates is responsible for geologic features and events such as volcanoes and lava flows, episodes of mountain building, and deep crustal faults and rifts.

How does gravity cause plates to move in a circle around the sun?

As the Sun is very large, it exerts a great gravitational force on Earth. The Sun’s gravitational force is like the tetherball rope, in that it constantly pulls Earth toward it. Instead, it travels in a nearly circular motion around the Sun, creating an orbit.

Why are the tectonic plates moving?

The plates can be thought of like pieces of a cracked shell that rest on the hot, molten rock of Earth’s mantle and fit snugly against one another. The heat from radioactive processes within the planet’s interior causes the plates to move, sometimes toward and sometimes away from each other.

How dense are tectonic plates?

Continental crust is broadly granitic in composition and, with a density of about 2.7 grams per cubic cm, is somewhat lighter than oceanic crust, which is basaltic (i.e., richer in iron and magnesium than granite) in composition and has a density of about 2.9 to 3 grams per cubic cm.

What is the density of the oceanic plate?

3.0 g/cm3
The average density of oceanic crust is 3.0 g/cm3, while continental crust has an average of 2.7 g/cm3.

Why is water important for plate tectonics quizlet?

Water released by pressurized wet lithosphere causes partial melting, melting mantle rock and causing it to rise up and break through the Earth’s crust.

How does the water cycle affect plate tectonics?

Even before the advent of plate tectonics Hubbert and Rubey (1959), showed that water in fault zones can act as a kind of lubricant that enables two adjacent blocks of rocks to move past each other. Because this movement gives rise to earthquakes, groundwater may also play an important role in the earthquake cycle.

What is asthenosphere in geography?

Asthenosphere. The asthenosphere is the denser, weaker layer beneath the lithospheric mantle. It lies between about 100 kilometers (62 miles) and 410 kilometers (255 miles) beneath Earth’s surface.

What is the driving force of plate tectonics?

The main driving force of plate tectonics is gravity. If a plate with oceanic lithosphere meets another plate, the dense oceanic lithosphere dives beneath the other plate and sinks into the mantle: this process is called subduction. However, convection is also driving plate tectonics.

Does gravity affect the direction of plate motion?

Though largely tangential, plate motion has a vertical component downward from the ridge crest, where the plate is generated, to the deep-sea trench where the plate presumably plunges through the asthenosphere and mesosphere of the earth. Thus, gravity generates an active driving component in the direction of motion.

How does the pressure gradient affect plate tectonics?

It’s the mantle convection that drives plate tectonics, because the continents are dragged around by the tops of the convective cells. And the pressure gradient enables convection because it creates both buoyancy and the need for buoyancy.

Why do plate tectonic plates move away from spreading ocean ridges?

Gravitational sliding away from a spreading ocean ridge takes place with plate movement driven because of the higher elevation of plates at ocean ridges. As fresh magma wells up at mid-ocean ridges to form new young, oceanic lithosphere, a higher elevation is formed at spreading ridges.