1. Earthquakes & Volcanoes
Unit 4: Tectonics NOTES
page 3
©Mark Place,
Revised 2010

2. Key Concepts & Questions
What is the driving force
behind crustal movement ?
Convection
Currents
in the
Mantle

3. Key Concepts & Questions
What provides the energy for this force?
radioactive decay

4. Key Concepts & Questions
What are the different types
of earthquake waves? And
how do they travel?

5. Key Concepts & Questions
p-waves
Travel
Through
Anything
primary waves
push-pull waves

6. Key Concepts & Questions
s-waves
Travels
Through
Solids Only
secondary waves
shear waves

7. Key Concepts & Questions
Where can most earthquake
epicenters and volcanoes be found?
at plate boundaries
"Ring of Fire"

8. To find an earthquake’s epicenter a seismologist
Key Concepts & Questions
To find an earthquake’s
epicenter a seismologist
must have data from at
least how many locations?

9. At least three

10. Key Concepts & Questions
How can scientists
infer the properties
of Earth’s interior?

11. by observing
earthquake waves

12. Remember: P-Waves go through everything
Remember: P-Waves go through everything. S-Waves do not got through liquids-will not go through outer core, so outer core is a liquid.

13. How do scientists know that Earth’s inner core is solid?
Key Concepts & Questions
How do scientists know that
Earth’s inner core is solid?

14. by the refraction (bending)
of P-waves

15. Also meteorites from space contain solid iron & nickel
Also meteorites from space contain solid iron & nickel. Scientists believe the Earth’s interior is also solid iron & nickel.

16. What can people do to protect themselves
Key Concepts & Questions
What can people do to protect themselves
during an earthquake?
get under desk/table
stand against interior wall
stay away from windows

17. Have an emergency evacuation plan.
What can people do to protect themselves before an earthquake?
Have an emergency evacuation plan.
Prepare food and water.
Build reinforced structures.

18. Key Concepts & Questions
What is the
Richter Scale and
how is it used?

19. a measure of earthquake strength
based on a scale from 1-10
Remember the new MERCALLI SCALE measures damage from I - XII

20. Earthquake Reference Table Questions
Please get out your ESRT p. 11!

21. Interactive P & S Wave Chart p. 11

22. 3600 kms If a p-wave arrives five minutes before the
s-wave arrives, how many kilometers from the
epicenter is a location?
3600 kms

23. 4800 kms If a p-wave arrives at 12:10:00 and the s-wave
arrives at 12:16:20, how many kilometers from
the epicenter is a location?
4800 kms

24. 9:04:20 An earthquake epicenter is 2600 kilometers
from a location. If the p-wave arrives at
9:00:20, what time will the s-wave arrive?
9:04:20

25. 1:13:20 An earthquake epicenter is 5200 kilometers
from a location. If the s-wave arrives at
1:20:20, what time did the p-wave arrive?
1:13:20

26. 3200 kms 4:40 later If a p-wave arrives 6 mins after an
earthquake occurs, how many
kilometers is the location from the
epicenter? How long after the p-
wave arrives will the s-wave
arrive?
3200 kms
4:40 later

27. Plate Tectonics Tectonics NOTES page 6 ©Mark Place, 2008-2009

28. What is the Theory of Continental Drift?

29. What is the Theory of Continental Drift?
Alfred Wegener, 1915
The continents were once a super-continent called Pangea.
the continents are plowing through the ocean floors---most people didn’t believe this

30. What evidence supports this theory?
Africa & South America look like they fit together
similar fossils, rocks, and glacial striations

31. What is the Theory of Plate Tectonics?
Earth's crust is made up of plates that ride on top of the asthenosphere
The plates move due to convection currents in the mantle

32. What evidence supports this theory?
distribution of earthquakes and volcanoes
sea-floor spreading

33. How do oceanic and continental crust compare with regard to thickness and density?
(ESRT
pg 10)
Thickness (pg 10)
high
low
thin
thick

34. continental crust oceanic crust
What are the primary rocks which make up the continental and oceanic crusts?
continental crust
oceanic crust
Low-density, light-
colored, coarse-
grained, felsic, igneous
rock
High density, dark-
colored, fine-grained,
mafic igneous rock
granite
basalt

35. What are these types of plate boundaries?
What are the key
characteristics for each?
Give an example of where each can be found.

36. oceanic-continental convergent boundary
trenches, volcanoes, deep earthquakes
Peru-Chile Trench

37. continental-continental convergent boundary
mountain building
Himalayas

38. transform fault
slide past one another
shallow earthquakes
San Andreas Fault

39. divergent plate boundary
new crust is made
Mid-Atlantic Ridge

40. What happens to the age of oceanic crust as distance increases from a ridge?

41. Age increases as distance increases from the ridge.

42. same pattern on opposite sides of the ridge proves sea-floor spreading
Explain how magnetic data can be used to show that oceanic crust is diverging at ridges. Use the diagram below to help explain your answer.
as new crust is made at ridges, the ferrous minerals (Fe) align according to where the magnetic poles are located
same pattern on opposite sides of the ridge
proves sea-floor spreading