Seismology
Name:
__________________________ is the study of __________________________ and __________________________
that move through and around the earth. A __________________________ is a scientist who studies earthquakes and
seismic waves.
1._________________ Theory
=an explanation for how _________________________
__________________________ during earthquakes.
a) As plates on opposite sides of a fault are
subjected to force and shift, they accumulate energy
and slowly __________________________ until their
internal strength is __________________________.
b) At that time, a sudden movement occurs
along the fault, __________________________ the
accumulated energy, and the rocks
__________________________ to their original __________________________ shape.
__________________________ =
point __________________________ the Earth where an earthquake begins
__________________________ =
point on Earth’s __________________________ above focus
How are Earthquakes Measured?
Mercalli Intensity Scale
The strength of an earthquake is usually
measured on one of two scales, the Modified
__________________________ Scale and the
__________________________ Scale.
The Mercalli Scale is a rather arbitrary set of
definitions based upon what people in the
area __________________________, and
their __________________________ of
damage to __________________________
around them. These scales are important to business and __________________________ in earthquake affected areas.
Richter Scale
It used a formula based on __________________________ of
the __________________________ recorded on a specific
type of seismometer and the __________________________
between the earthquake and the seismometer.
The Intensity Scale differs from the Richter Magnitude Scale in
that the effects of any one earthquake ___________________
greatly from __________________________, so there may be
many __________________________ values (e.g.: IV, VII)
measured for the same earthquake.
Each earthquake, on the other hand, should have only one
__________________________, although the various methods
of calculating it may give slightly different values
(e.g.: 4.5, 4.6).
The Richter Scale is designed to allow easier comparison of earthquake __________________________, regardless of
the __________________________.
2. Seismic Waves = the waves of __________________________ caused by the sudden breaking of rock
within the earth or an explosion.
They are the __________________________ that travels through the earth and is recorded on
__________________________.
Types of waves
The two main types of waves are __________________________ waves and __________________________ waves.
a) Body waves can travel through the ____________________________ (including _____________________)
b) __________________ waves can only move along the surface of the planet like ________________________.
Body Waves
P wave or __________________________ wave.
a) This is the __________________________ kind of seismic wave
b) the __________________________ to 'arrive' at a seismic station.
c) can move through _______________________ and ______________________, like water or the liquid layers
of the earth.
d) It __________________________ the rock it moves through just like sound waves push and pull the air.
e) also called __________________________ waves
S Waves
a) Stands for __________________________ wave.
b) the __________________________ wave you feel in an earthquake.
c) An S wave is __________________________ than a P wave
d) can only move through __________________________, not through any liquid medium.
e) move rock particles __________________________, or __________________________ -perpendicular to the
direction that the wave is traveling in (the direction of wave propagation).
Surface Waves
a) Travel only through the
__________________________
(__________________________)
b) are of a __________________________ than body
waves
c) __________________________ seen on a
seismogram as a result.
(________________________ waves)
d) arrive __________________________ body waves
e) surface waves are almost entirely responsible for the ___________________________________
_________________ associated with earthquakes.
f)
This damage and the strength of the surface waves are reduced in __________________________ earthquakes.
L waves
a) named after A.E.H. Love, a British mathematician who worked out the mathematical model for this kind of wave
in 1911.
b) the __________________________ __________________________ wave
c) moves the ground from __________________________.
d) Found only on the __________________________ of the crust, Love waves produce entirely
__________________________ motion.
Seismographs
a) measure the amount of
__________________________.
b) Many seismographs are used together as an
__________________________.
c) The data from this array is taken and
__________________________ is used to find the
__________________________ and other
information about the earthquake.
Major Hazards of Earthquakes
Safest & Most Dangerous Buildings
•
__________________________
•
__________________________ House - Safest
•
__________________________
•
__________________________
•
__________________________
•
Reinforced Concrete
•
__________________________ (Not Tidal
Waves!)
•
__________________________ Masonry
•
__________________________ - Most
Dangerous