Earthquakes and Seismic Waves

advertisement
• Is the shaking that results from the
sudden movement of rock along a fault.
• Is the shaking that results from the
movement of rock beneath Earth’s
surface
• The forces of plate movement causes
earthquakes. Plate movement produces stress
in Earth’s crust, adding energy to rock and
forming faults. Stress increases along a fault
until the rock breaks. An earthquake begins. In
seconds, the large amount of stored energy is
released.
• The point beneath Earth’s surface where
rock breaks under stress and causes an
earthquake
• The point on Earth’s surface directly
above an earthquake’s focus
• There are three types of seismic waves: P
waves, S waves, and Surface Waves.
• An Earthquake sends out two types of waves
from its focus: P waves and S waves. When
these two reach the surface at the epicenter,
surface waves develop.
• Also known as Primary Wave
• A type of seismic wave that compresses
and expands the ground like an
accordion.
P waves can travel through solids and liquids
• Also known as Secondary Waves or Shear
waves
• A type of seismic wave that moves the
ground surface up and down or side to
side
S waves can not travel through liquids
• A type of seismic wave that forms when
P waves and S waves reach Earth’s
surface.
Surface waves can be shakers (side to side) or rollers
(up and down)
• A Scale that rates earthquakes
according to their intensity and
how much damage they cause at
a particular place.
Twelve steps of the Mercalli scale (pg 185).
The same earthquake can have different Mercalli
ratings because intensity varies in different locations.
• A scale that rates an
earthquake’s magnitude
based on the size of its
seismic waves.
• A device that records ground movements
caused by a seismic waves
• The record of an earthquake’s seismic
waves produced by a seismograph
• The measure of an
earthquake’s strength based
on seismic waves and
movement along faults.
• A scale that rates an
earthquake by estimating the
total energy released.
Video
• https://www.youtube.com/watch?v=Yukp0bP
kQxs
• https://www.youtube.com/watch?v=_YLjIvJXh
pg
Download