1. 1. The minimum number of seismograph
stations necessary to determine the
location of an earthquake is .
2. Which point below is the focus of the
earthquake?
3. Which point below is the epicenter of the
earthquake?
A
B
3
B
A

2. ReviewReview
• P-waves
• S-waves
• L-waves
• Epicenter
• Focus
• Trilateration

3. VolcanoesVolcanoes
Any opening in the Earth’s
crust through which magma
reaches the surface
The openings are called
vents

4. VolcanoesVolcanoes
When magma reaches
the surface it is called
lava
Hills or mountains are a
result of this process

6. VolcanoesVolcanoes
•3 types of volcanoes

7. Shield VolcanoesShield Volcanoes
Broad and rounded
Made from stacks of
runny basaltic lava

9. Mauna Loa, Hawaii

10. Kilimanjaro, Africa

11. Cinder ConeCinder Cone
Smallest, most abundant
Violent eruptions with lots
of ash
Active for short time, then
become dormant

13. Paricutin, MexicoParicutin, Mexico

14. Composite ConeComposite Cone
Steep sided volcano made of
alternating layers of cinders
and lava
Usually found along plate
boundaries

16. Mount Fuji, JapanMount Fuji, Japan

17. OccurrencesOccurrences
Most
volcanoes
occur at or
near
subduction
zones

18. Arenal Volcano, Costa RicaArenal Volcano, Costa Rica

20. OccurrencesOccurrences
Some occur near
divergent plate
boundaries

22. IcelandIceland

23. OccurrencesOccurrences
Some occur in the
middle of plates
Hot spot volcanoes

24. Mauna Loa, Hawaii

26. Kilimanjaro, Africa

28. EruptionsEruptions
•Different types of
eruptions

29. Explosive Quiet

30. Different types of LavaDifferent types of Lava
Aa Lava

31. Pahoehoe LavaPahoehoe Lava

32. Skylight