A PPT showing the calculation on how to measure the magnitude of an earthquake.

2. A sudden violent shaking of the
ground, typically causing great
destruction, as a result of movements
within the earth's crust or volcanic
action.

3. • Earthquake is measured using the Richter Scale
• The Richter scale is a standard scale used to compare
earthquakes.
• The device was developed in 1935 by Charles F. Richter

4. • A network of geological monitoring stations,
each with instruments that measure how much
the ground shakes over time

5. • The goal of a seismograph is to accurately
record the motion of the ground during a
quake

6. • Seismographs record a zigzag trace that
shows how the ground shakes beneath

7. Primary
Waves
Surface
Waves
Surface
Waves

8. Micro
• Magnitude less
than-3.0
Minor
• Magnitude
in the rage
of 3.0 to
3.9
Light
• Magnitude
in the rage
of 4.0 to 4.9
Moderate
• Magnitude
in the rage
of 5.0 to
5.9 Strong
• Magnitude
in the rage
of 6.0 to 6.9
Major
• Magnitude in
the rage of 7.0
to 7.9
Great
•Magnitude
is greater
than or
equal to
8.0

10. Charles Richter's original formula was:
Where:
M= magnitude
A = the maximum displacement in millimeters
measured on a Wood-Anderson seismograph
t = the time in seconds between the arrival of the P
and S waves

11. • If the maximum displacement is 23
millimeters and the time between the arrival
of the P and S waves is 40 seconds. calculate
the magnitude of earthquake.
• Sol: M= logA + 3log8t - 2.92
M= log(23) +3log(8 x 40) -2.92
M= 1.36 + 7.52 - 2.92
M= 5.96