EARTH’S STRUCTURE AND HEAT TRANSFER

There are 7 layers of Earth’s inner workings

These layers include crust, upper mantle, transition region, lower mantle, lithosphere, outer core, and the inner core

The innermost part of Earth is measured at between 9,000 and 13,000 degrees Fahrenheit

The Layers of Earth’s Core

The Crusto The crust is about 5 miles deep into the

Earth from the bottom of the ocean, but 25 miles from the surface of a continent

o At the deepest part of the Earth’s crust, the temperature is about 1600 degrees Fahrenheit

o The Earth’s crust is broken into many different plates, which move around on the surface of Earth

THE LITHOSPHERE

The lithosphere is a section of the Earth in which

the crust and upper mantle meet

The lithosphere is comprised of rigid brittle rock

Right beneath the lithosphere is the

asthenosphere, which is the portion of the Earth

that causes plate movement

The transition layer of Earth is around 250-406 miles deep

Made of mainly basaltic magmas, but also contains amounts of calcium, aluminum, and garnet

The layer becomes dense when the garnet is cooled, but buoyant and light when it is heated

TRANSITION LAYER

THE UPPER MANTLE

The upper mantle and lower mantle together make up the largest portion of Earth

Both mantles are extremely hot and plastic in texture

The upper mantle is made up of olivine and pyroxene

This layer is not entirely solid but is also partially liquid

LOWER MANTLE

This layer is also sometimes referred to as the D’’ layer

The lower mantle is between 660 and 2890 km. deep

The lower mantle’s chemical composition consists of silicon, magnesium, and oxygen

This layer is also believed to have iron, calcium, and/or aluminum in it

The outer core of Earth is around 125 to 188 miles thick and is sometimes included as part of the lower mantle because of its geographical nature

Scientists say that the outer core of Earth is made of mostly iron and nickel

This layer of Earth can heat to temperatures between 7,200 and 9,000 degrees Fahrenheit

This would normally cause the iron and nickel to melt, but the pressure from the rest of the planet keeps it mostly solid

THE OUTER CORE

Lower mantle

The INNER CORE

The inner core is a solid portion of Earth that isn’t physically attached to the mantle, but is suspended by the molten outer core

The constant rotational motion of Earth creates electrical currents, giving our planet its magnetic field

Scientists also confirmed that 10% of this layer is oxygen and/or sulfur

Transfer of HeatIn the core of the Earth, all three forms of the transfer of heat are used. Radiation from the inner core heats most of the planet, as does conduction from the touching of each layer (excluding the inner core). Convection currents take place inside the outer core and the mantle where the molten magmas move around. Finally, the crust, upper mantle, and transitional layers are all mostly or entirely solid, so heat passes between them from conduction.

Our Earth is not only heated by its molten inner core, but also by the distant sun, which radiates heat all the way back to Earth

The sun’s heat causes temperature changes in the atmosphere, which is how we feel the different seasons on Earth- because we are either closer or farther away from the sun

Earth’s axis is on a tilt of about 23.5 degrees, causing one half of the world to be closer to the sun, then rotating away so the other half is in the same position

When we absorb energy from the sun, it passes through our atmosphere, causing a loss in heat, before making its way to us on land. In the ocean, it receives even less heat at a time because it must heat a larger body than one section of land

Temperature and The Sun

http://www.universetoday.com/73597/what-is-lithosphere/

http://www.science.nationalgeographic.com http://

www.eduweb.com/portfolio/earthsystems/plate_tectonics/tectonics1.html

http://www.mnh.si.edu/earth/text/4_1_5_0.html http://www.whoi.edu/NobleMetals/Fproject2.html http://

volcano.oregonstate.edu/vwdocs/vwlessons/lessons/Earths_layers/Earths_layers4.html

http://library.thinkquest.org/28327/html/universe/solar_system/planets/earth/interior/layers_of_earth.html

Sources Cited

http://www.vlab.msi.umn.edu/projects/natLowerMant.shtml

http://education.nationalgeographic.com/education/encyclopedia/core/?ar_a=1

http://www.oup.co.uk/oxed/children/oise/pictures/earth/earthcore/

Sources Cited