P-waves and S-waves are seismic waves that travel through the Earth. P-waves are compressional waves that push and pull material in the direction of travel, while S-waves are shear waves that cause material to vibrate perpendicular to the direction of travel. Studying these waves provides information about the composition and structure of the Earth's interior. The Earth can be divided into layers based on both mechanical properties and chemical composition. Mechanically, it consists of the lithosphere, asthenosphere, mesospheric mantle, outer core, and inner core. Chemically, it consists of the crust, upper mantle, lower mantle, outer core, and inner core. Seismic discontinuities exist between these layers

1. What are P-waves and S-Waves?

2. What are P-waves and S-Waves?
Explain the difference between
P-waves and S-waves?
Why is it important to study
P-waves and S-waves?

4. The Composition of the
Earth’s Interior

5. The structure of Earth can be defined in two
ways: by mechanical properties such as
rheology, or chemically.
Mechanically, it can be divided into
• lithosphere,
• asthenosphere,
• mesospheric mantle,
• outer core, and
• inner core.

6. Chemically, it can be divided into
• crust,
• upper mantle,
• lower mantle,
• outer core, and
• inner core.

7. Discontinuities in earth structure:
• Connard discontinuity Zone that separates the Earth’s upper
crust from the lower crust.
• Mohorovicic discontinuity. Zone that separates the Earth’s crust
from the asthenosphere.
• Repetti discontinuity
Zone that separates the upper mantle from the lower mantle.
• Gutenberg discontinuity Zone separating the lower mantle from
the core; it is located at a depth of about 1,800 mi.
• Lehman Discontinuity Zone that separates the Earth's outer core
from the Inner core

8. The Composition of the
Earth’s Interior
Objectives:
1. Examine data of the Earth’s interior.
2. Illustrate and explain Earth’s
internal composition.

9. Watch the movie
trailer for Journey to
the Center of the
Earth. Identify
characteristics that
you think are true
and those you think
are not true about
earth. Be prepared
to share.

10. Analyze the Data of the Earth’s interior.
Be able to present and explain your own
understanding through a constructed
drawing of the Earth’s interior.

12. Crust Mantle Core
(Inner and Outer)
Element
Approxima
te
% by
weight
Element Approxi
mate
% by
weight
Element Approxim
ate
% by
weight
Oxygen 46.6% Oxygen 44.8% Iron 85.5%
Silicon 27.7% Silicon 21.5% Silicon 6.0%
Aluminum 8.1% Magnesium 22.8% Nickle 5.20%
Iron 5.0% Iron 6.30% Sulfur 1.90%
Calcium 3.6% Carbon 0.20%
Sodium 2.8% Phosphorus 0.20%
Potassium 2.6%
Magnesium 2.1%
All others 1.5%
Source: http://www.knowledgedoor.com/2/elements_handbook/element_abundances_in_the_earth_s_core.html

13. Crust
Mantle
Core

14. Think of the layers of the
Earth like the layers of a cake.

15. Crust
Ocean Land

16. What element is the most abundant
in the Earth’s crust?
Crust
Element
Approximate
% by weight
Oxygen 46.6%
Silicon 27.7%
Aluminum 8.1%
Iron 5.0%
Calcium 3.6%
Sodium 2.8%
Potassium 2.6%
Magnesium 2.1%
All others 1.5%

17. • Thinnest layer of the Earth that ranges from only 2
miles in some areas of the ocean floor to 75 miles deep
under mountains
• Made up of large amounts of silicon and aluminum
• Two types of crust: oceanic crust and continental crust
• Composed of plates on which the continents and
oceans rest
Ocean Land
Crust

18. The Earth’s crust is like the skin of
an apple.

20. Mantle
Upper Mantle
Lower Mantle
Middle
Mantle
Convection
Currents

21. What elements make up most of the
mantle?
Mantle
Element Approximate
% by weight
Oxygen 44.8%
Silicon 21.5%
Magnesium 22.8%
Iron 6.30%

22. • Solid but capable of flow (like hot asphalt or
fudge)
• Thickest layer of the Earth (making up 70% of
the Earth’s mass)
• The hot material (magma) in the mantle rises
to the top of the mantle, cools, then sinks,
reheats, and rises again. These convection
currents cause changes in the Earth’s surface
Upper Mantle
Convection
Currents
Middle
Mantle
Lower Mantle
Mantle

23. What is the special feature of the upper
mantle?

24. Core
Inner
Core
Outer
Core

25. Outer
Core
• Molten (liquid) metal that is about 4,700°C
(8,500°F)
• Located about 1,800 miles beneath the
crust and is about 1,400 miles thick
• Composed of the melted metals nickel and
iron

26. How did scientists come to know
that the outer core is liquid?

27. Is the inner core solid, liquid or gas?
What keeps it in this phase?

28. Inner
Core
• Solid sphere composed mostly of iron
• It is believed to be as hot as 6,650°C (12,000°F)
• Heat in the core is probably generated by the
radioactive decay of uranium and other elements
• It is solid because of the pressure from the outer
core, mantle, and crust compressing it
tremendously

29. Inner Core
Solid
Outer Core
Liquid
Mantle
Crust
Lithosphere – Crust and
Upper Layer of the Mantle
Layer of the Mantle
(asthenosphere) that
consists of hot rock of
tar-like consistency,
which slowly moves

31. What do these two images tell
us about the layers of the Earth?

32. Temperature
increases as depth increases

33. Look at the information in the graph and
table below. What’s the relationship
between depth and density/pressure?

34. Density and Pressure
increase as depth increases

35. Which layer of the Earth has the
greatest temperature, pressure, and
density?
Core

36. Seismic Discontinuity
Conrad
Gutenburg
Moho/ Mohorovicic
Repetti

37. Conrad Discontinuity

41. Lehmann Discontinuity

42. Imagine you are going to take a
journey to the center of the earth
(like the movie but more accurate).
Write a short story describing your
journey. Include the layers of the
earth and descriptions of each
layer.

43. Search on other studies/data about the Earth’s
interior/composition.
10 Things You Never Knew About The Earth
https://www.youtube.com/watch?v=dgM8pjHl5bE