Unit 4 – Inside Earth
OVERVIEW - Surface and subsurface processes that are involved in the formation and
destruction of earth materials are identified in this unit.
Standard for this unit
Students will investigate the scientific view of how the earth’s surface is formed.
Compare and contrast the Earth’s crust, mantle, and core including temperature,
density, and composition.
Recognize that lithospheric plates constantly move and cause major geological
events on the earth’s surface.
Explain the effects of physical processes (plate tectonics, erosion, deposition,
volcanic eruption, gravity) on geological features including oceans (composition,
currents, and tides).
Students will investigate the scientific view of how the earth’s surface is formed.
Describe how fossils show evidence of the changing surface and climate of the
Earth.
---------------------------------------------------------Questions – students will be asked to answer these during this unit of study
#1 How are the earth’s layers alike and different?
#2 What challenges stand in the way of sending explorers to the center of the earth?
#3 How does the movement of lithospheric plates cause major events on earth’s surface?
#4 What evidence do scientists have that continents were once joined together?
#5 Why do mountains often occur in ranges thousands of kilometers long?
#6 What can fossils tell us about movements of the plates in the past?
1. The earth is layered with
CORE metallic, inner core is solid, outer
core is molten
MANTLE solid but is hot enough to flow
LITHOSPHERE made of crust and
uppermost mantle
2. Draw a picture of Earth’s layers.
3. Each layer differs in composition, density, and temperature.
4. Complete the chart.
Layer
CORE - Inner
CORE - outer
MANTLE Asthenosphere
Composition
Nickel & iron
(solid)
Iron & Nickel
(liquid)
Silicon,
oxygen, iron,
& magnesium
Density
12.6 – 13.0 g/cm3
Temperature
5000 C
9.9 – 12.2 g/cm3
4400 – 5000 C
3.3– 5.7 g/cm3
870 - 2200 C
Lithosphere (upper
Mantle and Crust)
CRUST – Continental
Granite &
3.0-3.3 g/cm3
oxygen,
silicon,
aluminum,
calcium, iron,
sodium,
potassium, &
magnesium
CRUST - Ocean
Basalt
2.7 – 3.0 g/cm3
5. Temperature and density increases as depth increases.
0 - 870 C
0 - 870 C
6. The composition of the earth changes with depth and layers.
7. The crust is the upper part of the rigid lithosphere and is of different composition
under land as opposed to the ocean floor.
8. The two types of crust are the oceanic crust which is more dense and it is made
primarily of basalt. The continental crust is made up mainly of granite.
9. Why is there different density between the types of crust? The oceanic crust is
squeezed by the immense pressure of the ocean above and the granite is transformed into
basalt.
10. The Lithosphere is the coolest layer of the earth.
11. Below the rigid lithosphere, the mantle consists of hot rock of tar-like consistency,
which slowly moves or flows.
12. Hot rocks rising and falling in the mantle/asthenosphere is called convection.
13. The lithosphere is the smallest layer of the Earth and it comprises 1% of the Earth’s
total mass.
14. The mantle comprises 66% of the Earth’s total mass.
15. The core is the hottest layer of the Earth and together they represent 33% of the
Earth’s total mass.
16. The outer core is molten and the inner core is a dense solid.
17. The mantle is solid but capable of flow (like hot asphalt or fudge). Under special
conditions like at hot spots and along plate boundaries the mantle or crust melt to make
magma, which may then rise to the surface to make a volcanic eruption.
18. Heat from the mantle and core creates convection currents.
19. Lithospheric plates on the scales of continents and oceans constantly move.
20. The lithosphere is divided into separate plates which move very slowly in response to
the mantle.
21. Plate movement causes major geologic events such as volcanoes, earthquakes, and
mountain formation.
22. At the edges or boundaries of the plates, the earth's crust is in motion.
23. The theory of plate tectonics connects the evidence for the formation, movement, and
destruction of the plates.
24. Major geological events, such as earthquakes, volcanic eruptions, and mountain
building, result from these plate motions.
25. Some changes in the earth’s surface are abrupt, such as earthquakes and volcanic
eruptions, while other changes happen very slowly such as uplift and wearing down of
mountains.
26. At divergent plate boundaries such as the mid-Atlantic ridge, new ocean floor is
created.
27. At convergent plate boundaries known as subduction zones, a trench and deep
earthquakes mark the zone where a slab of oceanic lithosphere descends into the mantle,
and volcanoes and mountain ranges form on adjacent land.
28. When continental crust meets continental crust at a convergent boundary, a collision
occurs, resulting in folds, faults, and high mountains.
29. Transform boundaries are where plates slide past each other. They connect other
plate boundaries and are characterized by earthquakes.
30. Earthquakes occur in the lithosphere.
31. Geologists analyze earthquake waves (seismic waves) to determine the composition
of the layers within Earth.
32. A machine that measures earthquakes is called a seismograph and the picture that
this machine draws is called a seismogram.
33. The focus is the exact location where an earthquake begins while the epicenter is the
spot on the Earth’s surface immediately above where the earthquake hit.
34. There are 3 main types of earthquake waves: S wave, P wave, and Surface wave
35. The P wave is the fastest wave and the least destructive.
36. The Surface wave is the slowest wave and the most destructive.
37. S waves are blocked by liquid. Since seismographs on the opposite side of the Earth
do not receive any S waves after an earth quake so scientists have concluded that the
Earth has a liquid layer
38. A shadow zone is formed on the opposite side of the Earth from where the
earthquake occurred because
S waves are blocked by liquid.
39. The Richter scale measures the strength of earthquakes.
40. A 5.0 earthquake is approximately 32 times stronger than a 4.0 earthquake.
41. If you are inside a building, the best thing to do when an earthquake occurs is
immediately hide under a desk or chair.
42. Moving plates cause major changes in a world map over tens of millions of years.
43. Pangaea was the most recent of a succession of supercontinents that have formed and
broken up over time.
44. Earthquakes represent sudden breaks in crust continuously stressed by plate
movement. Gradually over time, the same movements result in major crustal features.
Vocabulary
Plate Tectonics
Magma
Continental Drift
volcanic activities
fossil evidence
convection currents
Subduction
plate boundaries
Rifting
Transform
faults
Map of plate boundaries
Earthquakes
Volcanoes
Seismogram
Seismograph
Shadow Zone
Epicenter
Focus