2. `Seismic Waves These 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 recorded on
seismographs.
3. `Types Seismic Waves Body waves - arrive before the surface
waves emitted by an earthquake. These waves are of a higher
frequency than surface waves. Surface waves(L-Waves) - are of a
lower frequency than body waves, and are easily distinguished on a
seismogram as a result. Though they arrive after body waves, it is
surface waves that are almost entirely responsible for the damage
and destruction associated with earthquakes. This damage and the
strength of the surface waves are reduced in deeper
earthquakes.
4. ` Body Waves Primary Waves Secondary Waves push and pull
side to side
5. `Primary Waves Primary wavesare compression waves. They push
and pull the rocks of the earth's surface. They can move through
solid rock and fluids like water or the liquid core layers of the
earth And first to 'arrive' at a seismic station.
6. ` Primary waves push and pull on the rocks through which
they are traveling. This creates a back and forth movement on the
Earth's surface. This is just like sound waves pushing and pulling
the air. Have you ever heard a big clap of thunder and heard the
windows rattle at the same time? The windows rattle because the
sound waves were pushing and pulling on the window glass much like
P-waves push and pull on rock. Primary Waves
7. `Secondary Waves Secondary waves travel slower than primary
waves. Also called shear waves "or Transverse Waves. They create a
side to side motion in the rocks through which they are
traveling.
8. `Secondary Waves Unlike the other earthquake waves, S-waves
cannot travel through water or the liquid rock of the Earth's core
layer. They can Travel through solid only-waves will rock buildings
side- to-side.
9. `Remember... Primary WavesSecondary Waves Also Called as
Compression Waves. They Push and Pull the rock in the earths
surface Also Called as Shear/Transverse Waves. They Push and Pull
the rock in the earths surface
10. ` Surface Waves(L-Waves) Moves along the surface of the
earths surface. They move up and down. Love WavesRaleigh Waves
11. `Surface Waves(L-Waves) Land waves move along the surface
of the earth and cause it to move up and down like something
bobbing on the surface of the ocean.
12. `Surface Waves(L-Waves) Land waves only move along the
surface of the earth. Their speeds vary depending on the material,
rock or soil, forming the surface. These waves cause the surface to
move up and down. These are the waves that cause The to buildings
and other structures during an earthquake.
13. ` Named after A.E.H. Love, a British mathematician who
worked out the mathematical model for this kind of wave in 1911.
Love Waves Love waves travel with a lower velocity than P or S
waves, but faster than Rayleigh waves. These waves travels in
lithosphere only.
14. ` These waves are a type of surface acoustic wave that
travel on solids Rayleigh Waves Named for John William Strutt, Lord
Rayleigh, who mathematically predicted the existence of this kind
of wave in 1885. Rolls along the ground just like a wave rolls
across a lake or an ocean. Because it rolls, it moves the ground up
and down, and side-to-side in the same direction that the wave is
moving. Most of the shaking felt from an earthquake is due to the
Rayleigh wave, which can be much larger than the other waves.
15. ` Seismic Waves
16. `Remember... Love Waves travels through lithosphere only.
Has Low Velocity but faster than Rayleigh waves. Rayleigh Waves
travel on solids and Rolls along the ground
17. `Questions: 1. Other term for primary waves and secondary
waves 2. Differentiate the P and s waves 3.Love waves are named
after a mathematician. What is the name of the mathematician ?
4.How about rayleigh waves. What is the name of the mathematician ?
The end
18. ` Seismic Waves Body Waves P Waves S Waves Surface Waves
Love Waves Rayleigh Waves Remember...