Transcript Types of Stress that cause Earthquakes

Types of Stress that cause
Earthquakes
http://www.youtube.com/watch?v=-zNyVPsj8zc&feature=related
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What does the elastic rebound theory describe?
A. the build-up and release of stress during an earthquake
B. the fluctuations in groundwater prior to an earthquake
C. the formation of mountain ranges by successive earthquakes
D. the strength of an earthquake
Which of the following types of seismic waves arrive at a seismograph first?
A. P waves
B. S waves
C. surface waves
D. All of these waves arrive at the same time.
Who developed the procedure used to measure the size of an earthquake?
A. Charles Richter
B. James Hutton
C. Charles Darwin
D. Harry Hess
How many seismograph stations are needed to locate the epicenter of an earthquake?
A. 1
B. 2
C. 3
D. 4 or more
Earthquakes that originate at depths greater than 100 km are associated with ______ plate boundaries.
A. convergent
B. divergent
C. transform
D. convergent, divergent, and transform
Which of the following observations may indicate a forthcoming destructive earthquake?
A. an increase in the frequency of smaller earthquakes in the region
B. rapid tilting of the ground
C. rapid changes in water levels in wells
D. all of these
1.
2.
3.
4.
5.
6.
What does the elastic rebound theory describe?
A. the build-up and release of stress during an earthquake
B. the fluctuations in groundwater prior to an earthquake
C. the formation of mountain ranges by successive earthquakes
D. the strength of an earthquake
Which of the following types of seismic waves arrive at a seismograph first?
A. P waves
B. S waves
C. surface waves
D. All of these waves arrive at the same time.
Who developed the procedure used to measure the size of an earthquake?
A. Charles Richter
B. James Hutton
C. Charles Darwin
D. Harry Hess
How many seismograph stations are needed to locate the epicenter of an earthquake?
A. 1
B. 2
C. 3
D. 4 or more
Earthquakes that originate at depths greater than 100 km are associated with ______ plate boundaries.
A. convergent
B. divergent
C. transform
D. convergent, divergent, and transform
Which of the following observations may indicate a forthcoming destructive earthquake?
A. an increase in the frequency of smaller earthquakes in the region
B. rapid tilting of the ground
C. rapid changes in water levels in wells
D. all of these
What is an Earthquake?
• Earthquake - the vibrations produced when a
rock snaps and breaks under different types of
stress.
The Elastic Rebound Theory
• Rocks will bend until they reach their Elastic Limit.
• Then they will break (crack)
– Forming a Fault
BrainPop
How do Earthquakes Occur?
• Rocks on a fault are jagged & get stuck when
plates move.
• Stress Builds
• Rocks bend until they can’t & then snap back to
their original position. (Elastic Rebound Theory)
Parts of a Fault
You can
HANG off a
Hanging Wall
You can walk
up a Foot
Wall
1. Normal Fault
• Caused by tension stress (tension means to
pull apart)
• Causes hanging wall to move downwards.
• Where I might see one? Divergent Boundary
Normal Fault
Normal Fault
Normal Fault
The Basin and Range Province in the
western United States is the most famous
area featuring basin and range topography.
It is also one of the largest as it spans almost
300,000 square miles and comprises almost
all of Nevada, western Utah, southeastern
California, and portions of Arizona and
northwestern Mexico. Additionally, the area
is comprised of miles of mountain ranges
separated by flat desert plains and basins.
Within the Basin and Range Province, the
relief is abrupt and the basins normally range
from 4,000 to 5,000 feet (1,200- 1,500 m),
while most of the mountain ranges climb
3,000 to 5,000 feet (900-1,500 m) above the
basins.
Death Valley, California is the lowest of the
basins with its lowest elevation of -282 feet (86 m). Conversely, Telescope Peak in the
Panamint Range to the west of Death Valley
has an elevation of 11,050 feet (3,368 m),
showing the enormous topographic
prominence within the province.
This area also affected a significant portion
of the United States’ history as it was a
major barrier to westward migration because
the combination of desert valleys, bounded
by mountain ranges made any movement in
the area difficult. Today, U.S. Highway 50
crosses the region and crosses five passes
over 6,000 feet (1,900 m) and is considered
"The Loneliest Road in America."
2. Reverse Fault
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Caused by compressional stress
Hanging wall moves up
Earthquakes!!!!
Where would I find this fault? Convergent
boundaries
Thrust fault = special Reverse Fault
• Angle of fault plane is shallow.
3. Strike Slip Fault
• Caused by shear stress (rocks moving
horizontally past one another)
• Movement is only horizontal
• EARTHQUAKES!!!
• Where would I see these? Transform
boundaries
Strike-Slip Fault (Transform)
Strike – Slip Fault
Strike-Slip Fault (Right Lateral)
Strike Slip Fault
http://www.youtube.com/watch?v=VSgB1IWr6O4