Download Chapter 9 Tectonics, Earthquakes, and Volcanoes

Chapter 9
Tectonics, Earthquakes, and
Volcanoes
Elemental Geosystems 5e
Robert W. Christopherson
Charles E. Thomsen
Tectonics, Earthquakes,
and Volcanoes
Earth’s Surface Relief Features
Crustal Formation Processes
Crustal Deformation Processes
Orogenesis (Mountain Building)
Earthquakes
Volcanism
Earth’s Surface Relief Features
Crustal Orders of Relief
First order of relief
Second order of relief
Third order of relief
Hypsometry
Earth’s Topographic Regions
Earth’s Hypsometry
Figure 9.2
Earth’s Topographic Regions
Figure 9.3
Crustal Formation Processes
Continental Shields
Building Continental Crust
Terranes
Continental Shields
Figure 9.4
Crustal Formation
Figure 9.5
North American
Terranes
Figure 9.6
Terrane Formation
Crustal Deformation Processes
Folding and Broad Warping
Faulting
Normal fault
Reverse (thrust) fault
Strike-slip fault
Faults in concert
Stress and Strain
Figure 9.7
Folding
Folding
Figure 9.8
Zagros
Zagros
Crush
Crush
Zone
Zone
Figure 9.9
Domes and Basins
Figure 9.10
Folding
Folding
Folding
Faults
Transform Faults
Normal Fault
Figure 9.11
Reverse Fault
Figure 9.11
Strike-Slip Fault
Figure 9.11
San Andreas
Fault
Figure 9.12
Anatolian Fault and
San Andreas Fault
Figure 9.13
Faulted Landscapes
Figure 9.14
Orogenesis
(Mountain Building)
Types of Orogenies
The Grand Tetons and the Sierra Nevada
The Appalachian Mountains
World Structural Regions
Alpine
Orogeny
Figure 9.15
Oceanic-Oceanic
Collision
Japanese Boundary
Figure 9.16
Oceanic-Continental
Collision
Andean Boundary
Figure 9.16
Continental-Continental
Collision
Himalayan Boundary
Figure 9.16
India Collision with Asia
Teton Range in Wyoming
Figure 9.17
The
Appalachian
Mountains
Figure 9.18
World Structural Regions
Figure 9.19
Earthquakes
Expected Quakes and Those of Deadly
Surprise
Earthquake Essentials
The Nature of Faulting
The San Francisco earthquakes
The Southern California earthquakes
Earthquake Forecasting and Planning
Elastic Rebound
Buildup and Release of Stress
Figure 9.20
Anatomy of an Earthquake
Figure 9.21
Seismographs
Earthquake Scales
Modified Mercalli scale
Measures damage
Richter scale
Measures waves on paper
Moment magnitude scale
Measures energy released
Modified Mercalli Scale
Measures damage
Roman numerals I to XII
I = barely felt
XII = just smoking rubble
Richter scale
Logarithmic scale
Measures amplitude of seismic waves
As recorded 100 km from epicenter
On Wood-Anderson seismograph
Mag 1 to mag 2 = 10x increase in wave size,
33x in energy
Mag 1 to mag 7 = 1,000,000x increase in wave
size, 64,100,000,000,000x (64 trillion)
increase in energy
Moment Magnitude Scale
Measures Energy released
Distance fault moved
Area of break
Strength of rock
Impacts of Earthquake Prediction
Figure 9.22
Parkfield
Section of San Andreas fault
Most heavily monitored section
Repeating earthquakes
Every 22 years
Creeping above, locked below
Seismographs comparing 1922, 1934,
1966 Parkfield earthquakes
2004!
1857, 1881, 1901, 1922, 1934 and 1966
Volcanism
Volcanic Features
Location and Types of Volcanic Activity
Effusive Eruptions
Explosive Eruptions
Volcano Forecasting and Planning
Volcanoes!
Volcano is vent at surface above magma
chamber
If it hasn’t blown in human history its
dormant
If it has its active
Volcanoes
Three types of volcanoes
Stratovolcano = Mt. Fuji, Mt. St. Helens
Lava and ash flows over time
Shield volcano = Hawaii
Oceanic crust flows like maple syrup
Plug dome = Mt. Lassen
Continental crust flows like mashed potatoes
Volcanism
Volcanic Features
Location and Types of Volcanic Activity
Effusive eruptions
Explosive eruptions
Mount Pinatubo eruption
Volcano Forecasting and Planning
Volcanoes
Location determines chemical composition
of magma
Chemical composition determines eruptive
activity
Eruptive activity determines shape
Volcanoes
Magma contains dissolved gasses
As magma nears surface pressure is
released and gas comes out of solution
If gas can flow through magma then
effusive eruption
If gas is blocked then explosive eruption
Volcanoes
Subducting continental material (graniticlike) flows like mashed potatoes
Pressure from gas builds until explosion
Basaltic magma flows like maple syrup
Lava fountains yes, explosions no
Hawaiian Basaltic Lava
Figure 9.23
Volcanic Settings
Figure 9.24
Tectonic Settings and Volcanic Activity
Volcano Types
Rift Valley
Figure 9.25
Mount Hood and Flood Basalt
Figure 9.26
Hawaiian Volcanic Activity
Figure 9.27
White’s Isle, New Zealand
Figure 9.29
Pu‘u O‘o Crater, Hawai‘i
Figure 9.32
Shield and Composite Volcanoes
Figure 9.33
Composite Volcanoes
Figure 9.34
Debris Avalanche and Eruption of Mount St Helens, Washington
End of Chapter 9
Elemental Geosystems 5e
Robert W. Christopherson
Charles E. Thomsen