Download Earth*s Formation

Earth’s Formation
Layers of the Earth
• What is in the center of our Earth?
• What do we stand on?
• What fills up the holes in our Earth?
• What is above us?
How do scientists know what is inside
Earth?
• Earthquakes
– Earthquakes transmit energy and we can measure
that energy to “see” Earth’s interior
– These waves change speeds when they go through
materials of different densities
• How do earthquakes transmit energy?
– Via seismic waves
Other Evidence
• Average density of the Earth
• Composition of meteorites
• Earth’s magnetic field
What we found
• We found out our Earth has layers! Just like
your baby food jar model. And why does the
Earth have layers???
– Because of differences in density
Earth’s Formation
• http://www.bbc.co.uk/science/earth/earth_ti
meline/earth_formed#p00fzslq
Mesosphere
Crust
• Thin, but rigid top layer
• Made up primarily of basalt rock (ocean) and
granite rock (continents)
– The oceanic crust is denser then the continental
rock!
Mantle
• Partially molten rock that can flow
• Makes up 68% of the mass of the Earth
Core
• Made up of nickel and iron, which makes this
layer magnetic and very dense
• Divided into layers
– Outer Core: liquid
– Inner Core: solid
But wait, there’s more. . .
• The Earth has layers due to density
differences, above the crust, though, what do
we encounter?
• Gas has mass and can be confined to a
volume, so is there layers to our air?
– Yes, yes there is
Our Atmosphere
Layers of the Atmosphere pg. 55
• Troposphere: only layer that has weather,
contains 90% of the mass
• Stratosphere: where airplanes fly
• Mesosphere: coldest layer (0 C to -90 C)
Layers of the Atmosphere (cont)
• Thermosphere: technically hot, but it would
feel cold to us
• Exosphere: blends into space
• REMEMBER: The atmosphere has layers
because of density differences, just like our
Earth!