Download Earthquakes

Earthquakes
What causes
Earthquakes?
Earthquakes

What is happening when an Earthquake
occurs?
Earthquakes

What is happening when an Earthquake
occurs?

The Earth’s crust moves suddenly.
Earthquakes

What is happening when an Earthquake
occurs?

The Earth’s crust moves suddenly.

Built up tension between two plates is released
very quickly and the plates move.
Earthquake key terms:

Foot wall: The plate that doesn’t move
during an Earthquake.
Earthquake key terms:
Foot wall: The plate that doesn’t move
during an Earthquake.
 Hanging wall: The plate that moves
during an Earthquake.

Earthquake key terms:
Foot wall: The plate that doesn’t move
during an Earthquake.
 Hanging wall: The plate that moves
during an Earthquake.
 Fault plane:The plane along which the
break between two plates occurs.

Earthquake key terms:
Foot wall: The plate that doesn’t move
during an Earthquake.
 Hanging wall: The plate that moves
during an Earthquake.
 Fault plane:The plane along which the
break between two plates occurs.
 Fault line: The line in the surface of the
Earth caused by the fault plane.

Earthquake key terms:

Focus: Exact point where the
earthquake begins.
Earthquake key terms:
Focus: Exact point where the
earthquake begins.
 Epicenter: place on the surface of the
Earth directly above the focus.

Earthquake key terms:
Focus: Exact point where the
earthquake begins.
 Epicenter: place on the surface of the
Earth directly above the focus.
 P-Waves: 1st set of waves which travel
quickly through the interior of the Earth
in a spiral motion.

Earthquake key terms:

S-Waves: Secondary waves – move
slowly through the Earth in an “S”
shaped motion.
Earthquake key terms:
S-Waves: Secondary waves – move
slowly through the Earth in an “S”
shaped motion.
 Surface Waves: move in a circular
pattern on the surface of the Earth.
Causes damage to the surface of the
Earth.

Earthquake types:

The type of Earthquake depends on
what type of boundary is between the
two plates.
Earthquake types:

The type of Earthquake depends on
what type of boundary is between the
two plates.

Strike-slip Earthquakes: Result from
transform boundaries
Earthquake types:

The type of Earthquake depends on
what type of boundary is between the
two plates.


Strike-slip Earthquakes: Result from
transform boundaries
Normal Earthquakes: Result from divergent
boundaries
Earthquake types:

The type of Earthquake depends on
what type of boundary is between the
two plates.



Strike-slip Earthquakes: Result from
transform boundaries
Normal Earthquakes: Result from divergent
boundaries
Reverse Earthquakes: Result from
convergent boundaries.
Strike-slip Earthquakes
Strike-slip Earthquakes
Normal Earthquake:
Reverse (Thrust) Earthquake:
Graben:
Horst:
Where do Earthquakes
happen?
Where do Earthquakes
happen?

Most of the time they happen where
plates meet.
Where do Earthquakes
happen?
Most of the time they happen where
plates meet.
 They can happen in the middle of a
plate as well.

Where do Earthquakes
happen?
Most of the time they happen where
plates meet.
 They can happen in the middle of a
plate as well.


This is usually caused by the crust
dropping like a sink hole.
Measuring Earthquakes:

The Richter Scale: Measures the
amount of energy released by an
earthquake (magnitude).
Measuring Earthquakes:

Mercalli scale: Measures the intensity of
an earthquake (how much damage is
done).