4. ⦁ A wave can be described
as a disturbance that
travels through
a medium from one
location to another
location.
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5. Defination of seismic waves :
A wave of energy that is generated by an earthq
uake or other earth vibration and that travels w
ithin the earth or along its surface.
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6. Seismology
the study of vibrations within Earth
vibrations are caused by various
events, including earthquakes, extra
terrestrial impacts, explosions, storm
waves hitting the shore, and tidal
effects.
8. ◾ Around 132 AD, Chinese scientist Chang
Heng invented the first seismoscope, an
instrument that could register the occurrence
of an earthquake.
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13. • Seismic waves are the waves of energy caused
by the sudden breaking of rock within the earth
or an explosion.They are the energy that travels
through the earth and is recorded on
seismographs.
• There are several different kinds of seismic
waves, and they all move in different ways.The
two main types of waves are body waves and
surface waves.
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14. 1. Body waves
◾Primary waves
◾Secondary waves
2. Surface waves
◾ Love waves
◾ Rayleigh waves
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15. ⦁ Body waves are those waves which travells
through the interior of the earth.
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16. ⦁ P Waves (compression wave)
⦁ The first kind of body wave is the Pwave or primary wave.
This is the fastest kind of seismic wave. The P wave can move
through solid rock and fluids, like water or the liquid layers of
the earth. It pushes and pulls the rock it moves through just
like sound waves push and pull the air.
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17. ⦁ Primary waves (P-waves) are compressional
waves that are longitudinal in nature.
⦁ P waves are pressure waves that travel faster
than other waves through the earth to arrive
at seismograph stations first hence the name
"Primary".
⦁ These waves can travel through any type of
material, including fluids, and can travel at
nearly twice the speed of S waves
17
18. ⦁ S wave (transverse wave)
⦁ The second type of body wave is the Swave or
secondary wave, which is the second wave you feel
in an earthquake. An S wave is slower than a P
wave and can only move through solid rock. This
wave moves rock up and down, or side-to-side.
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19. ⦁ S-waves lag behind P-waves as they travel
1.7 times slower and can only pass through
solid rock. However they do more damage
because they’re bigger and shake the ground
vertically and horizontally.
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21. ⦁ S-waves are shear waves, which move particles
perpendicularly to their direction of propagation.
⦁ They can propagate through solid rocks because
these rocks have enough shear strength. The shear
strength is one of the forces that hold the rock
together, and prevent it from falling into pieces.
⦁ Liquids do not have the same shear strength: that
is why, if you take a glass of water and suddenly
remove the glass, the water will not keep its glass
shape and will just flow away.
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22. ⦁ Surface waves are those waves which travels
through the surface of the earth.
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23. 1. Love waves
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⦁ A type of seismic surface wave in which
particles move with a side-to-side motion
perpendicular to the main propagation of the
earthquake. The amplitude of this motion
decreases with depth.
⦁ Love waves cause the rocks they pass
through to change in shape. They travel
faster than Rayleigh waves.
⦁ the Love waves at about 3.5 km/s
25. ◾ A type of seismic surface wave that moves with a
rolling motion that consists of a combination of
particle motion perpendicular and parallel to the
main direction of wave propagation.
◾ The amplitude of this motion decreases with
depth. Like primary waves, Rayleigh waves are
alternatingly compressional and extensional
(they cause changes in the volume of the rocks
they pass through).
◾ Rayleigh waves travel slower than Love waves.
◾ the Rayleigh waves at 3.0 km/s
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27. ⦁ The Rayleigh waves "roll" along the surface,
described as "up and over backwards roll."
⦁ These surface waves do most of the
damage to structures. The Love waves
shake us from side to side and the Rayleigh
waves shake us up and down
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28. ⦁ On the basis of seismic waves we differentiate
different layers of earth
⦁ On the basis of seismic waves we sub
classified the layers.
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29. ⦁ Use in the identification of hydrocarbons
reservoirs.
⦁ Oil and gas exploration.
That’s end.
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30. Identify the word being describe.
1. The waves that can only move through
solid rock, not through any liquid
medium.
2. It is the waves that has a lower
frequency than body waves.
3. It is the fastest surface wave that
moves the ground from side-to-side.
4. The study of vibrations within Earth.
31. 5. What do you call the waves of energy
caused by the sudden breaking of rock
within the earth or an explosion?
6. It is an instrument used to detect and
record earthquakes.
7. What do you call the waves that arrive
before the surface waves emitted by an
earthquake?
32. 8. This is the fastest kind of seismic wave,
and, consequently, the first to arrive at a
seismic station.
9. The other term used to describe P Waves
because of its pulling and pushing motion.
10. It is the waves that rolls along the ground
just like a wave rolls across a lake or an
ocean.
33. 1. S Waves
2. Surface Waves,
3. Love Waves
4. Seismology
5. Seismic waves
6. seismometer, Seismographs
7. Body Waves
8. P Wave
9. Compressional waves
10. Rayleigh wave
