Name __________________________
PS/ES Per ____
Date _________________
Mr. Landsman
Define the terms below and label the diagram.
Fault_______________________________________________________________
___________________________________________________________________
_________________________________________________________________
Focus______________________________________________________________
___________________________________________________________________
___________________________________________________________________
Epicenter___________________________________________________________
___________________________________________________________________
___________________________________________________________________
EarthquakeWaves____________________________________________________
___________________________________________________________________
_______________________________________________________________________________
What is an Earthquake?
• Sudden movement in the Earth’s crust that releases energy in the form of
__________________
• Movement occurs along areas of __________________________ in the
earth’s crust.
How is energy transmitted?
• Energy is transmitted through seismic (earthquake) ________________ or
vibrations
• Types of earthquake waves:
• P- waves: Primary waves
• Travel fastest, arrive ______________________
• S- waves: Secondary waves
• Travel more slowly than P-waves, arrive _______ P-wave
Wave Propagation (transmission):
Longitudinal waves:
• Particles move parallel to the direction the wave travels
• Primary wave (p-waves) is a __________________________ wave
• They make the ground vibrate _________________________________
• Arrive at seismic recording stations ___________________________
• Can travel through solids, liquids and gases (Solids and Fluids)
Transverse waves:
• Particles move perpendicular to direction of wave motion
• Secondary waves are _____________________________ waves
• Travel about ½ as fast as ________________________
• Make the ground vibrate from side to side, up and down
• Can only travel through ________________________ ONLY
See demo
Velocities:
– in the same medium, P waves travel at a greater velocity (_________)
than S waves. However, the velocities of seismic waves depend upon the physical
properties of the material through which the waves travel (medium). Higher
density media result in a higher velocity of wave propagation.
Summary:
Wave
Type
Relative Velocity
It go like dis
Transmitted through…
P
S
How are earthquakes detected?
Seismograph:
• an instrument attached to the Earth designed to detect crustal shifts
Seismogram:
• recording of the earthquake waves by the seismograph machine
Note: this image is an output from a machine. It is NOT what the actual waves look like.
How is the strength of an earthquake measured?
Mercalli scale (un-scientific):
– Based upon _____________________ from people in affected area
including damage and what was felt
– Also known as Mercalli Intensity
Richter________________ Scale:
– Measured using the wave size (amplitude) on seismogram
– Magnitude scale (ex. An earthquake of 5 has 10 times as much
energy released as a 4)
Examples:
Magnitude 1 = 10 energy units
Magnitude 2 = ___________units
What happens if an earthquake on the ocean floor displaces a large amount of
seawater?
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
Warning Signs:
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
Emergency Preparation Actions:
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
Modified Mercalli Intensity Scale from FEMA
I. People do not feel any Earth movement.
II. A few people might notice movement if they are at rest and/or on the upper floors of tall
buildings.
III. Many people indoors feel movement. Hanging objects swing back and forth. People outdoors
might not realize that an earthquake is occurring.
IV. Most people indoors feel movement. Hanging objects swing. Dishes, windows, and doors
rattle. The earthquake feels like a heavy truck hitting the walls. A few people outdoors may feel
movement. Parked cars rock.
V. Almost everyone feels movement. Sleeping people are awakened. Doors swing open or close.
Dishes are broken. Pictures on the wall move. Small objects move or are turned over. Trees might
shake. Liquids might spill out of open containers.
VI. Everyone feels movement. People have trouble walking. Objects fall from shelves. Pictures fall
off walls. Furniture moves. Plaster in walls might crack. Trees and bushes shake. Damage is slight
in poorly built buildings. No structural damage.
VII. People have difficulty standing. Drivers feel their cars shaking. Some furniture breaks. Loose
bricks fall from buildings. Damage is slight to moderate in well-built buildings; considerable in
poorly built buildings.
VIII. Drivers have trouble steering. Houses that are not bolted down might shift on their
foundations. Tall structures such as towers and chimneys might twist and fall. Well-built buildings
suffer slight damage. Poorly built structures suffer severe damage. Tree branches break. Hillsides
might crack if the ground is wet. Water levels in wells might change.
IX. Well-built buildings suffer considerable damage. Houses that are not bolted down move off
their foundations. Some underground pipes are broken. The ground cracks. Reservoirs suffer
serious damage.
X. Most buildings and their foundations are destroyed. Some bridges are destroyed. Dams are
seriously damaged. Large landslides occur. Water is thrown on the banks of canals, rivers, lakes.
The ground cracks in large areas. Railroad tracks are bent slightly.
XI. Most buildings collapse. Some bridges are destroyed. Large cracks appear in the ground.
Underground pipelines are destroyed. Railroad tracks are badly bent.
XII. Almost everything is destroyed. Objects are thrown into the air. The ground moves in waves
or ripples. Large amounts of rock may move.
Name____________________
PS/ES Per___
Date_______________
Mr. Landsman
The field map below represents Modified Mercalli scale reports from witnesses of an earthquake
in New York. Plot isolines on the map at an interval of one ‘Mercalli’. Answer the questions.
1
1
1
1
2
2
4
3
6
4
1
5
1
2
2
1
1
1. Place an X on the likely location of the epicenter.
2. Name one type of damage that may have been observed at the
epicenter._____________________________________________________________________________
3. What caused the earthquake waves?
_____________________________________________________________________________________
4. Citizens in Utica were at the epicenter of the earthquake but did not report any visible faults.
Explain how this is possible (use the word “focus” in your answer).
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________