EARTHQUAKES
EARTHQUAKES
HOW DO WE MEASURE THEM?
• Seismometer
• Seismograph
= the paper
HOW DO WE MEASURE THEM?
• Seismometer
HOW DO WE MEASURE THEM?
• Seismometer
• Modern ones are embedded intothe bedrock to cancel out human made vibrations (cars, jackhammers, etc.)
• Uses magnets to create a current
• Computers measure the current
HOW DO WE MEASURE THEM?
• Richter Scale
• Each level is 10 times the amplitude of the previous
• Eg: 5.0 magnitude is 10 times 4.0
HOW DO WE MEASURE THEM?
• Richter Scale
HOW DO WE LOCATE THEM?
• Primary and
Secondary
Waves
HOW DO WE MEASURE THEM?
• Richter Scale
RICHTER SCALE – IN PERSPECTIVE
HOW DO WE LOCATE THEM?
• Triangulation
• Measure the time between P and S Waves
• Figure out radial distance
• Where all 3 circles meet is epicenter
FOCUS (HYPOCENTER) VS EPICENTER
• After Shocks
• Difficult to
define
• Proximity is
used
EFFECTS OF EARTHQUAKES
• Tsunamis
EFFECTS OF EARTHQUAKES
• Tsunamis
• Japan – March
11, 2011
EFFECTS OF
EARTHQUAKES
• Tsunamis
• Japan – March
11, 2011
• 8.9 magnitude
EFFECTS OF EARTHQUAKES
• Tsunamis
• Japan – March
11, 2011
• 8.9 magnitude
EFFECTS OF EARTHQUAKES
• Liquefaction
• Occurs in loose soils that are saturated
• Turns into quicksand
EFFECTS OF EARTHQUAKES
• Liquefaction
• Occurs in loose soils that are saturated
• Turns into quicksand
EFFECTS OF EARTHQUAKES
• Liquefaction
• Occurs in loose soils that are saturated
• Turns into quicksand
EFFECTS OF EARTHQUAKES
• Liquefaction
• Niigata
1964
EFFECTS OF EARTHQUAKES
UNIT PROJECT