Bell ringer (write the question) What are the three mountain types? What stress is responsible for creating the following: Strike-slip fault Reverse-fault Normal Fault What plate boundary is mostly responsible for earthquakes?

What are the three types of mountains? Folded mountains Formed at convergent boundaries Form when rock layers are squeezed together and pushed upward Volcanic mountains Form when melted rock erupts onto earth’s surface Can be found on land or ocean floor Fault-block mountains Formed by tension at normal faults

What stress is responsible for creating the following: Strike-slip fault, Reverse-fault, and Normal Fault Reverse fault Compression squeezing Normal Fault Tension Stretching Strike slip fault Shear stress twisting

What plate boundary is mostly responsible for earthquakes? Transform boundary

What is an earthquake? Earthquakes are ground movements that occur when blocks of rock in Earth move suddenly and release energy. The energy is released as seismic waves that cause the ground to move. 5

What are the components of an Earthquake? Focus The starting point where earthquakes begins within earth Epicenter The epicenter is located directly above the focus on the surface of the earth The epicenter is where the earthquake strongest destruction can be found 6

What causes earthquakes? Unit 2 Lesson 6 Earthquakes What causes earthquakes? Most earthquakes occur near a tectonic plate boundary, which is where two or more tectonic plates meet. The movement of tectonic plates breaks Earth’s crust into a series of faults, which are breaks in Earth’s crust along which blocks of rocks move. The release of energy that accompanies the movement of rock along a fault is what causes an earthquake. Copyright © Houghton Mifflin Harcourt Publishing Company 7

What causes earthquakes? Unit 2 Lesson 6 Earthquakes What causes earthquakes? Stress causes deformation, which is the process by which rock changes shape. As stress on rock increases, the energy stored in it increases. When the stress is released, the rock sometimes returns to its original shape. Copyright © Houghton Mifflin Harcourt Publishing Company 8

What is elastic rebound? Earthquakes accompany the release of energy during elastic rebound. When the rocks break and rebounds, it releases energy as seismic waves. Elastic rebounds explains what causes earthquakes.

What causes earthquakes? Unit 2 Lesson 6 Earthquakes What causes earthquakes? Deformation in which rock can spring back to its original shape is called elastic deformation. The return of rock to its original shape after elastic deformation is called elastic rebound. Copyright © Houghton Mifflin Harcourt Publishing Company 10

Unstable Ground Where do earthquakes happen? Unit 2 Lesson 6 Earthquakes Unstable Ground Where do earthquakes happen? Most earthquakes happen at or near tectonic plate boundaries. At tectonic plate boundaries, stress builds up from tectonic plates colliding, separating, or grinding past each other. Copyright © Houghton Mifflin Harcourt Publishing Company 11

Where do earthquakes happen? Unit 2 Lesson 6 Earthquakes Where do earthquakes happen? At divergent boundaries, tension stress causes normal faults to form. Earthquakes tend to be shallow because the crust is thin. Copyright © Houghton Mifflin Harcourt Publishing Company 12

Where do earthquakes happen? Unit 2 Lesson 6 Earthquakes Where do earthquakes happen? At convergent boundaries, rock is squeezed, causing reverse faults to form. Earthquakes can be very strong and deep. Copyright © Houghton Mifflin Harcourt Publishing Company 13

Where do earthquakes happen? Unit 2 Lesson 6 Earthquakes Where do earthquakes happen? At transform boundaries, shear stress pushes tectonic plates in opposite directions. Earthquakes tend to be relatively shallow. Copyright © Houghton Mifflin Harcourt Publishing Company 14

What are some damages/natural disasters that can result from an earthquake? The ground and structures shake during an earthquake. May cause buildings to collapse. Tsunamis can occur due to earthquakes