Earth’s Layers Notes
1. Two main ways scientists collect
information about the Earth is by drilling into it and by using seismic
information.
2. Seismographic equipment measures
the seismic or shockwaves produced by earthquakes.
3. A model is used to study parts of
science where the real object cannot be studied.
4. Earth is made of three layers; the
crust, the mantle, and the core.
5. All life exists either on the
surface or within the first few meters of the crust.
6. The outer layer of the Earth is
called the crust.
7. The deepest hole on earth is 12
kilometers or 40,000 feet deep & only goes into the crust. We have never
been able to dig a hole through the crust.
8. The crust
is made up of different kinds of rock, but the two main types are granite and
basalt.
9. Basalt is much stronger than
granite. Ocean crust is made only of basalt. (basalty)
10. Five elements make up more than
90 percent of the crust; oxygen, silicon, aluminum, iron, and calcium.
11. Another
name for the crust is the lithosphere, the solid portion of the Earth.
12. The
scientists believe that Earth’s crust, or lithosphere, is broken into several
segments or plates.
13. The
Earth’s surface can be divided into two kinds of crust, continental crust and
ocean crust.
14. Continental crust is found under
the landforms or continents and is usually about 35 kilometers thick; however,
it may be up to 70 kilometers thick in mountainous areas.
15. The upper part of continental
crust is made up of granite and the lower part is basalt.
16.The
temperature of the crust goes from 20 degrees Celsius at the surface to 870
degrees Celsius at the bottom.
17. Oceanic crust is much thinner
than continental crust. It averages only
5-7 kilometers thick.
18. Ocean crust is only made of
basalt which is much denser and stronger than continental crust.
The Mantle!
19.The Earth
has a very thin boundary or layer between the crust and the mantle called the Mohorovicic Discontinuity or Moho.
20. The Moho
is sort of like a fence between the crust and the mantle.
21. The mantle is the second layer of
the Earth and it is the biggest.
22. The mantle makes up 80 percent of
the Earth’s total volume and 68% of it’s
MASS!!!
23. The mantle has a lot more iron
than the crust and the amount of iron increases as you go deeper.
24. The top part of the mantle is
soft and gooey and is called the asthenosphere. The lithosphere sort of slides on top of the asthenosphere.
25. At the
top of the mantle, the temperature averages about 870 Celsius and near the
bottom it reaches 2200 Celsius.
The Core!
26. The core
is really two layers, an outer core and an inner core.
27. The outer core is believed to be
2,250 kilometers deep. The temperature goes
from 2,200 Celsius on the upper edge and gets hotter the deeper you go, up to 5,000
Celsius.
28. The
outer core is liquid, very dense melted iron and nickel.
29. The inner core is believed to be
1,300 kilometers in depth. Temperatures
are believed to be about 5,000 Celsius throughout.
30. The inner core is solid iron and
nickel. It is solid because of the
incredible pressure on it.
31. density
of the Earth increases as we go deeper and deeper and temperature gets
hotter. The amount of iron also increases as we get deeper.
32. IMPORTANT FACT! As we go
deeper and deeper into the Earth, both pressure and temperature increase!