3. As tectonic plates move, friction causes the rocks
at plate boundaries to stretch or compress.
*Potential (stored) energy in rocks transformed to
ground-shaking kinetic (movement) energy
causes an earthquake.
4. * Earthquakes begin in the lithosphere at a point
called the focus.
*Seismic waves reach Earth’s surface at a point
above the focus called the epicenter.
5. *The release of potential energy to kinetic energy
in rocks results in seismic waves.
These waves radiate from the focus traveling
about 20 times faster than the speed of sound.
6. *Body Waves and Surface Waves:
*Body Waves originate from the focus of an
earthquake
*When body waves reach the epicenter, they
become surface waves. They move more slowly,
and causes more damage.
7. Body Waves originate from the focus of an
earthquake.
*P-waves (primary waves) are compression
waves that push and pull rock as they move
through it.
*S-waves (secondary waves) move sideways and
up and down, traveling about 3 k/sec.
◦ *S-waves do not travel through liquids.
8. *Earthquakes are measured by the magnitude or
size of the energy of the seismic waves.
*There are several different scales to measure
earthquakes.
◦ The *Richter Scale measure the amplitude of the seismic
waves recorded on a seismograph.
◦ The *Moment Magnitude Scales rates the total energy
released by an earthquake.
◦ The *Mercalli Scale rates how much damage was
caused to buildings, the ground and to people.
9. 1. What is the difference between the focus and
the epicenter of an earthquake?
2. Draw a diagram that shows the difference
between a P-wave and an S-wave.
3. Describe the differences between P-waves and
S-waves.
10. 4. An earthquake in the eastern hemisphere of
Earth is recorded in the western hemisphere.
However, only P-waves are recorded. Review
what you know about P and S waves and come
up with an explanation for this data.
5. Define the work of a geologist, paleontologist,
and seismologist, each in your OWN words. If you
had to choose to be one of these scientists, which
would you be and why?
12. Faults are breaks in the Earth’s crust.
Most faults occur along the boundaries of tectonic
plates.
In the USA, the San Andreas Fault of California is
the most active fault.
13. The direction a block of rocks moves along
different types of Faults depends on the kind
of stresses they are under.
*Faults are classified according to the way the
rocks on one side of the Fault move in relation
to the rocks on the other side.
14. Faults Are Classified By How Rocks Move
• *There are Three main types of Faults:
– 1. Normal Faults
– 2. Reverse Faults
– 3. Strike-Slip Faults
• More than one type of Fault may be present
along the same Plate Boundary.
• However the type of Fault that is most common
along a boundary depends if the plates are
pulling apart, pushing together, or scraping past
one another at that boundary.
15.
16. Faults Are Classified By How Rocks Move
A Fault forms a flat plane that extends
horizontally and vertically.
Blocks of rock move along the Fault Plane
during an earthquake.
18. *Along a Normal Fault, the block of rock above
the Fault Plane slides down in relation to the
other rock.
*Normal Faults are often found at Divergent
Plate Boundaries.
Earthquakes along Normal Faults are common
near boundaries where Tectonic Plates are
moving apart, such as the in the Great Rift
Valley of Africa.
19.
20.
21. *Along a Reverse Fault, the block of rock
above the Fault Plane move up in relation to
the other block.
Reverse Faults are often found at Convergent
boundaries.
22.
23. *Along a Strike-Slip Fault the blocks move
sideways on either side of the Fault Plane.
Strike-Slip Faults are often found at transform
plate boundaries.
*These Faults can occur where plates scrape
past each other. The San Andreas is a Strike-Slip
Fault.
24.
25. Over time, movement of rocks along Normal
and Reverse Faults can push up mountains
and form deep Valleys.
As rock moves along Strike-Slip Faults, rocks
that were once continuous layers can become
separated by hundreds of kilometers.
26. 1. Explain how divergent plate boundaries and
normal faults are related.
2. Explain how convergent plate boundaries and
reverse faults are related.
3. Explain how transform plate boundaries are
related to strike slip faults.
4. What kind of fault is the San Andreas Fault?
27. 1. Color the fault blocks, 2. Cut out, 3. Fold all
straight lines and fit. 4. Glue: use a small amount
of glue on tabs. Use a small piece of tape to hold
glued surfaces together until glue dries.
