Question

The layer of the earth where mantle convection occurs and on which the earth's crust rests is the _____. a outer core b asthenosphere c lithosphere d inner core

Answer 1

The earth has four layers; the crust, the mantle, the outer core and the inner core. The Earth’s magnetic field is the combination from the convection it receives from the outer core and the Coriolis Effect. The layer of earth where mantle convection occurs is the asthenosphere. The answer is letter B. The outer core is composed mostly of liquid nickel and iron. It is expected to have that state of metal because it has a higher temperature. The inner core cannot hold much of the magnetic field because of its high temperature and high pressure that exceeds the outer core. The temperature decreases however as the layer goes outwards.  

Answer 2

The Layer of the Earth where mantle convection occurs and on which the Earth’s crust rests is the asthenosphere.  

Further Explanation;

The Earth is made up of layers which includes;

The Crust

• It is the outermost layer of the Earth that is very hard.
• Crust is made up of granite and basalt. It is divided into continental plates which drift slowly with time.

Mantle  

• It is the second layer of the earth and takes up to 80 percent of the Earth.
• Mantle is divided into Lithosphere and the Asthenosphere.
• Convection currents occurs in the mantle  

Lithosphere  

• It is made up of Earth’s outermost layer, the crust, and the uppermost portion of the mantle.
• Lithosphere lies over the asthenosphere such that if a material of the asthenosphere solidifies, it becomes part of the lithosphere.
• Lithosphere is comprised of a large number of fragments, each known as the tectonic plate. These tectonic plates are in constant motion and are floating over the plastic material underneath.

Asthenosphere

• It is the upper portion of the Earth’s mantle which is the middle layer of the Earth.
• Asthenosphere has a higher temperature compared to the lithosphere and hence its rock are plastic and can flow.
• Asthenosphere is more dense and viscous compared to lithosphere.

Convection current  

• In the mantle, convection currents make the mantle to move. They occur when the lower mantle heats up and rises, cools down then gets pushed down since it is heavier.
• Convection currents are due to the density of a fluid that is related to its temperature in the mantle.
• Hot rocks lower in the mantle are less dense than the cooler rocks below, therefore the hot rocks rises while the cooler rocks sinks due to gravity.

Outer core

• It is the third layer of the earth and surrounds the inner core. It is the only liquid layer of the Earth.  
• This layer is about 2100 miles long and temperatures ranging from 4,000 to 5,000 degrees Celsius.

Inner core

• It is the innermost layer of the earth.
• It contains impure iron that contains sulfur, nickel and other elements in small portions.
• Its temperatures ranges between 5,000 and 7,000 degrees Celsius.

Keywords: Layers of the Earth, Mantle, Lithosphere, asthenosphere, convection current

Learn more about:

• Layers of the Earth: brainly.com/question/466763
• Lithosphere: brainly.com/question/2855870
• Asthenosphere: brainly.com/question/6708010
• Mantle convection: brainly.com/question/13160211

Level: High school

Subject; Geography  

Topic: The Earth

Sub-topic; Layers of the Earth