Unit 4 Dynamic Earth Processes Volcanoes - PowerPoint PPT Presentation

1 / 21
About This Presentation
Title:

Unit 4 Dynamic Earth Processes Volcanoes

Description:

Students know why and how earthquakes occur and the scales used to measure their intensity and magnitude ... instruments called seismographs Record seismic waves ... – PowerPoint PPT presentation

Number of Views:68
Avg rating:3.0/5.0
Slides: 22
Provided by: Rita114
Category:

less

Transcript and Presenter's Notes

Title: Unit 4 Dynamic Earth Processes Volcanoes


1
Unit 4 Dynamic Earth ProcessesVolcanoes
Earthquakes
  • Earth Sci 3d
  • Students know why and how earthquakes occur and
    the scales used to measure their intensity and
    magnitude
  • Earth Sci 3e
  • Students know there are 2 kinds of volcanoes one
    kind with violent eruptions producing steep
    slopes and the other kind with voluminous lava
    flows producing gentle slopes

2
Volcano
  • What is it?
  • A hill or mountain formed when molten rock
    (magma) comes to Earths surface
  • Magma reaching the surface is called lava

3
2 Types of Volcanoes
  • 1. Explosive Eruptions
  • 2. Non-explosive Eruptions
  • The silica content of magma helps determine
    whether the volcanic eruption is explosive or
    quiet.
  • Silica is the material formed from silicon
    oxygen

4
Explosive Eruption
5
Explosive Eruption Volcano
  • 1. Cinder Cone Volcano
  • Has steep slope
  • Build from various materials
  • Ash
  • Cinders
  • Glass
  • Lava fragments
  • Rocks

6
Explosive Eruption Volcano
  • 2. Composite Volcano
  • Most common type
  • Has steep slope
  • Explodes both lava ash
  • Has alternating layers of lava, ash mud

7
Composite Volcano
8
Non-Explosive Eruption
9
Non-Explosive Eruption Volcano
  • Shield Volcano
  • Built from layers of basaltic lava
  • Basalt dark, fine-grained volcanic rock
  • Not very steep gentle slopes
  • Ex Hawaiian Islands

10
(No Transcript)
11
What causes volcanoes?
  • The formation of magma
  • Mantle rock melts when the temperature increases
    or the pressure decreases

12
What causes volcanoes?
  • Where do volcanoes form?
  • Tectonic Plate Boundaries!!!!

Ring of Fire
13
What causes volcanoes?
14
What causes volcanoes?
  • Hot Spots

15
Earthquake
16
Earthquake
  • Why How it occurs
  • Earths crust movement causes the stresses
    applied
  • These stresses can cause rocks to bend and
    stretch
  • Eventually rocks will break away from one another
  • Area in which the rocks break and move is called
    a fault
  • Vibrations produced is called an earthquake

17
Measuring Earthquakes
  • Seismology
  • Use instruments called seismographs
  • Record seismic waves
  • The height (amplitude) of the lines are used to
    measure the energy released from the earthquake
    called the magnitude
  • Magnitude
  • Usually determines the strength of the break
  • Is measured using the Richter scale

18
Seismograph
19
Tsunami
  • Caused by the movement of the ocean floor
  • An earthquake in a subduction zone can cause
    tsunami
  • When the stress reached the point where the
    overlying plate could no longer bend without
    breaking, it snapped and jerked upward.

20
Tsunami
21
Videos
  • Volcano
  • http//video.nationalgeographic.com/video/player/e
    nvironment/environment-natural-disasters/volcanoes
    /volcanoes-101.html
  • Earthquake
  • http//video.nationalgeographic.com/video/player/e
    nvironment/environment-natural-disasters/earthquak
    es/earthquake-101.html
  • Tsunami
  • http//www.youtube.com/watch?vw3AdFjklR50
Write a Comment
User Comments (0)
About PowerShow.com