1. Volcanoes and Earthquakes

2. DAY 1
Objective:
I can explain how a volcano is structured

3. What is a Volcano?
A mountain formed of lava and/or pyroclastic material

4. Anatomy of a Volcano Vent Crater Magma Chamber Magma Tube
Opening in the crust
Crater
Steep-walled depression at the top
Magma Chamber
Where the molten rock waits
Magma Tube
Links the vent to the magma chamber

6. Day 2
Objective:
I can explain what happens when a volcano erupts

7. Magma verse Lava Magma Lava Molten rock under the surface of Earth
Molten rock on the surface of Earth

8. Factors Affecting Eruption
Magma Composition
Magma Temperature
Amount of Dissolved Gases

9. Viscosity of Magma Substance’s resistance to flow
Hotter the magma, more fluid and less viscous
Directly related to its silica content
More silica, greater its viscosity (slower movement)

10. Dissolved Gases Consist of water vapor and carbon dioxide
More gases, the more violent the eruption

11. Gases
70% water vapor
15% carbon dioxide
5% nitrogen
5% sulfur

12. Pyroclastic Material Fragments ejected during eruptions
From very fine to several tons
Ex:
Volcanic Ash
Cinders (lapilli)
Volcanic Bombs

13. Other Eruption Results
Pyroclastic Flow
Consist of hot gases, glowing ash, and large rock fragments
Races down the steep slope
Lahar
Mudflow that occurs when volcanic debris becomes saturated with water and rapidly moves down steep volcanic slopes

14. DAY 3
Objective
I can describe the locations of volcanoes and the relationship between volcanoes and plate tectonics

15. Plate Tectonics & Volcanoes
Relationship
Plate movement provided the mechanism by which mantle rock melts to generate magma

16. Ring of Fire
Area around the pacific ocean with extreme volcanic activity
This shows the Pacific Plate Boarder

17. Intraplate Activity Occurs with a plate, not a plate boundary
Hot Spots
Small volcanic region a few hundred kilometers across within a plate
Ex: Hawaiian Islands

18. DAY 4 Objective: I can explain what an earthquake is
I can explain why earthquakes happen

19. What is an Earthquake? Vibration of Earth
Produced by a sudden release of energy
Movement along a fault line

20. Parts of an Earthquake Focus Epicenter Fault
Point within Earth where the earthquake starts
Epicenter
Location on the surface directly above the focus
Fault
Associated with earthquakes activity where movement has occurred

21. Causes of Earthquakes Elastic Rebound Hypothesis
Release of built-up energy
Most earthquakes are produced by the rapid release of elastic energy stored in rock that has been subjected to great forces
When the strength of the rock exceeded, it suddenly breaks, causing the vibrations of an earthquake

22. Foreshock vs. Aftershock
Small earthquakes before the big quake
Aftershock
Smaller earthquakes after the big quake

23. Seismic Science Seismology Seismograph Seismogram
Study of earthquake waves
Seismograph
Instruments that record earthquakes
Seismogram
The record made by a seismograph

24. Day 5 Objective: I can explain how to locate origin of an earthquake
I can explain how to measure the strength of an earthquake

25. Earthquake Waves Two Main Types Surface Waves Body Waves P-waves
S-waves

26. Surface Waves Seismic waves that travel along Earth’s outer layer
Moves up & down and side to side
Most destructive
Last to arrive at the seismograph

27. Body Waves P-Waves (primary waves)
They push (compress) and pull (expand) rocks in the direction the wave travels
Can travel through solids, liquids and gases
Fastest waves
First to the seismograph

28. S-Waves (secondary waves)
Shakes particles at right angles to their travel
Can only travel through solids
2nd to the seismograph

29. Locating Earthquakes
The difference in velocity of a P-Wave & S-Wave provides a way to locate the epicenter
Use a travel-time curve graph
Needs at least three seismograph station data

30. Strength of an Earthquake
Two different types of measurements to describe the strength of an earthquake
Intensity
Magnitude

31. Earthquake Intensity
A measure of the amount of earthquake shaking at a given location based on the amount of damage

32. Earthquake Magnitude
A measure of the size of seismic waves or the amount of energy released at the source of an earthquake

33. The Richter Scale Measures magnitude
Based on the amplitude of the largest seismic wave
A TEN-FOLD system
Largest earthquake record= 9.6 (CHILE)

34. Moment Magnitude Scale
More precise
Amount of displacement that occurs along a fault zone
Most widely used
Estimates energy released by earthquakes

35. Mercalli Intensity Scale
How much damage occurs
Depends on:
Strength
Distance from the epicenter
Nature of the surface material
Building design

36. DAY 6 Objective: I can describe the dangers of an Earthquake
I can explain how to make earthquake predictions

37. Earthquake Hazards Seismic Vibrations
Damage to building depends on several factors
Intensity of vibration
Duration of vibration
What type of material built on
Design of the structure

38. Liquefaction
Stable soil turns into a liquid that is not able to support building or other structures

39. Tsunami
Large ocean wave created by an earthquake

40. Landslides Fires Caused by ruptured gas lines
Greatest damage to structures
Sinking of the ground triggered by the vibration
Fires
Caused by ruptured gas lines

41. Predicting Earthquakes
Short Range
Measure uplift, subsidence and strain in the rocks
Short-range predictions have not been successful

42. Long Range Based on the idea that earthquakes are repetitive
Seismic Gap
An area along a fault where there has not been any earthquake activity for a long period of time