Earthquakes
Essential Question: _______________________________________________________________________________
__________________________________________________________________________________________________
Whose Fault is it?

________________are _________________ in Earth where movement has occurred

Because earthquakes occur when _________ plates rub _____________, they are often said to
occur on ______________________
What are the types of Faults?

To relieve this stress, the rocks tend to ___________, ____________, or ___________

If the force is great enough the rocks will ________________.

This breaking produces an earthquake.
 An _____________________ is vibrations produced by breaking rock
 Abrupt shakings of the Earth is caused by the ___________ of built up ______________ on
the Earth’s surface
What are the 3 types of Faults?

3 types of forces act on rocks: tension, compression, and shear
 _____________________- caused by rock above the fault moving downward in relation to
the rock below the fault
 _____________________- result from compression forces that _________________ rock.

If rock breaks from forces pushing from opposite directions, rock above a reverse
fault surface is forced up and over the rock below the fault surface.
 At a ______________________, rocks on either side of the fault are moving past each
other without much upward or downward movement

The ______________________________ is the boundary between two of Earth’s
plates that are moving sideways past each other.
What are the features of an Earthquake?

Seismic Waves- waves _________________________________________, can move the ground
_________________ and backward, ______ and down, and ________ to side
What are the types of Seismic Waves that are produced?

Primary Waves (P-Waves)- cause particles in rocks to move back and forth in the ___________
direction that the wave is _________________

Secondary Waves (S-waves)- move through Earth by causing particles in rocks to move at
___________________________ to the direction of wave travel.

Surface Waves- are seismic waves that travel along Earth’s ____________________________
 These waves cause ____________ of the destruction resulting from earthquakes
How do we locate an Earthquake?

The different ____________ of seismic waves allow scientist to determine the epicenter
 Primary waves move _______________
 ___________________ waves follow
 Surface waves move ____________ and arrive at the seismograph station ________
How do we locate an Earthquake?

Seismic waves from earthquakes are measured with an instrument known as a
____________________
 Consists of a rotating drum of paper and a pendulum with an attached pen
 The paper record of a seismic event is called a seismogram
How do we measure an earthquake?

We can measure earthquakes by its:
 __________________ – a measure of the _______________ on an earthquake at a particular
________________
 __________________: a measure of the _______________ or amount of _______________
released during an earthquake

The Richter scale is used to describe the ________________ of an earthquake and is based on
the ______________ of the lines on the __________________

The Mercalli Scale is based on actual ____________________ of ________________________
Earthquake dangers…

Most earthquake damage occurs when _______________________ cause building, bridge, and
roads to collapse

However, an earthquake under the _______________ causes a sudden movement of the
_____________ floor

The movement ___________ against the water, causing a powerful wave that can travel
thousands of kilometers in all directions

These ocean waves caused by earthquakes are called seismic sea waves, or ________________