Types of Stress that cause Earthquakes

Types of Stress that cause Earthquakes

http://www.youtube.com/watch?v=-zNyVPsj8zc&feature=related

1. What does the elastic rebound theory describe?A. the build-up and release of stress during an earthquakeB. the fluctuations in groundwater prior to an earthquakeC. the formation of mountain ranges by successive earthquakesD. the strength of an earthquake

2. Which of the following types of seismic waves arrive at a seismograph first?A. P wavesB. S wavesC. surface wavesD. All of these waves arrive at the same time.

3. Who developed the procedure used to measure the size of an earthquake?A. Charles RichterB. James HuttonC. Charles DarwinD. Harry Hess

4. How many seismograph stations are needed to locate the epicenter of an earthquake?A. 1B. 2C. 3D. 4 or more

5. Earthquakes that originate at depths greater than 100 km are associated with ______ plate boundaries.A. convergentB. divergentC. transformD. convergent, divergent, and transform

6. Which of the following observations may indicate a forthcoming destructive earthquake?A. an increase in the frequency of smaller earthquakes in the regionB. rapid tilting of the groundC. rapid changes in water levels in wellsD. all of these

1. What does the elastic rebound theory describe?A. the build-up and release of stress during an earthquakeB. the fluctuations in groundwater prior to an earthquakeC. the formation of mountain ranges by successive earthquakesD. the strength of an earthquake

2. Which of the following types of seismic waves arrive at a seismograph first?A. P wavesB. S wavesC. surface wavesD. All of these waves arrive at the same time.

3. Who developed the procedure used to measure the size of an earthquake?A. Charles RichterB. James HuttonC. Charles DarwinD. Harry Hess

4. How many seismograph stations are needed to locate the epicenter of an earthquake?A. 1B. 2C. 3D. 4 or more

5. Earthquakes that originate at depths greater than 100 km are associated with ______ plate boundaries.A. convergentB. divergentC. transformD. convergent, divergent, and transform

6. Which of the following observations may indicate a forthcoming destructive earthquake?A. an increase in the frequency of smaller earthquakes in the regionB. rapid tilting of the groundC. rapid changes in water levels in wellsD. 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 FaultBrainPop

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

• 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