Hi nobleresearcher,
Thank you for your question.
The earth is very similar to a peach in its structure. In the center
is a solid core. Surrounding the core is the inner core, then the
mantle, which is covered in the earths 'skin' or crust.
The Structure Of The Earth
http://www.zephryus.demon.co.uk/geography/resources/earth/struc.html
"Our planet was most probably created about five billion years ago. At
first it was just a ball of molten rock and gasses with little order
to its structure. The immense amount of heat energy released at this
time is still being radiated, even today, as the planet slowly cools
down.
As the cooling began, more dense materials such as iron (Fe) sank into
the core of the Earth, while lighter silicates (Si), other oxygen (O)
compounds, and water rose towards the surface. In consequence distinct
layers began to form.
The Earth is made up of several of these different layers. The outer
layer is called the Crust. It is made of the lighter, less dense,
rocks that floated to the surface when the Earth was formed and is
between 35km and 70km thick. The deepest mine in the world is only
3.3km deep, and nobody has ever been able to drill down further than
15km. Everything that exists below this depth is worked out by
scientists using evidence from earthquakes, volcanoes and meteorites.
Being relatively cold, the crust is rocky and brittle, so it can
fracture during earthquakes. The crust is not a continuous layer of
rocks but consists of large masses, called plates, which are free to
drift slowly across the surface of the planet. There are two types of
crust - Continental and Oceanic. Continental crust is less dense (
lighter), much older and much thicker than Oceanic crust. Continental
crust floats on the mantle rather like an iceberg floats in water.
Continental Crust : 35 - 70km thick, up to 3500 million years old
Oceanic Crust : 6km thick, nowhere older than 200 million years
The layer of rock below the crust is called the Mantle. This is about
2,900km thick and contains most of the mass of the Earth. The upper
part of the mantle is solid but at greater depths the heat causes the
rock to behave more like a liquid. The high pressure, however, stops
the rock from melting. It becomes 'plastic' at temperatures in excess
of 1000°C and can flow. The rocks are mainly composed of iron (Fe),
magnesium (Mg), aluminium (Al), silicon (Si), and oxygen (O)
compounds.
Very hot rocks in the lower part of the mantle rise up through the
cooler, upper, layers. As the rocks rise they cool and flow sideways.
They then sink down again towards the core. This movement is called
convection.
Below the mantle is the Core. This is probably liquid with a solid
centre made of iron with a few other metals such as nickel. The
centre, or Inner Core is incredibly hot, about 5,000°C and subjected
to a pressure of about 4 million atmospheres! It is this extreme
pressure that keeps the inner core in a solid state."
=========
Inside the Earth
http://pubs.usgs.gov/publications/text/inside.html
=========
Earth's Interior
http://www.seismo.unr.edu/ftp/pub/louie/class/100/interior.html
Model for Structure of Earth
http://zebu.uoregon.edu/~soper/Earth/earthstructure.html
=========
Best regards,
tlspiegel |
