6th Grade Earth Science chapter 4 study guide

What are the three types of waves that are created by earthquakes? Describe their characteristics.

1. P waves: compress and expand the ground like an accordion 2. S waves: can vibrate from side to side 3. surface wave: move more slowly that P and S waves, but they can produce severe ground movements.

What are faults and describe the three types of faults?

Fault is a crack or break in rock along which rock surfaces can slip. 1. Normal Fault: Rock is pulled apart two pieces of Earth's crust. 2. Reverse fault: has the same structure as a normal fault, but the blocks move in the reverse direction. 3. Strike-Slip Faults: The rocks in either side of the fault slip past each other sideways, with little up or down motion.

What is stress and describe the three different types of stress?

Stress is a force that acts on rock to change its shape or volume. 1. Tension: force pulls on the crust and thins rock in the middle. 2. compression: force that squeeze rock until it fold like a giant trash compactor. 3. Shearing: force that pushes a mass of rock in two opposite directions

How do scientist record these waves?

seismograph : is the record of an earthquake's seismic waves produce by a seismograph

How are earthquakes formed?

The forces of plate movement cause earthquakes. Plate movements produce stress in Earth's crust forming faults. Stress increases along a fault until the rock slips or break causing earthquakes.