1. PRESENTATION ON EARTHQUAKE
SILVER OAK COLLEGE OF
ENGINEERING & TECHNOLOGY
Prepared by :
Adviser :
Nirav R Dabhi 11CLD09
Dulari Mehta Simal B Gandhi 11CLD10
Khushbu Bhojak Parth J Bhavsar 11CLD12
Ketul P Mandavia 11CLD14

2. • An earthquake (also known as a quake, tremor or temblor) is the
result of a sudden release of energy in the Earth's crust that
creates seismic waves.
• An earthquake is caused by a sudden rupture (break) of the earth
• The most largest earthquake of 9.5 magnitude earthquake in
Chile in 1960.
• The most recent earthquake of 9.0 magnitude earthquake in
Japan in 2011 (as of March 2011), and it was the largest Japanese
earthquake since records began.
• It struck at 7.58am on December 26, 41 miles off the coast of
north-west Sumatra where 200,000 are now thought to have been
killed in just 15 minutes.

3. • Passing the Elastic Limit Causes Faulting
• Applied stresses can cause rocks to bend and stretch
• Eventually rocks will break away from one another
• Area in which the rocks break and move is called a fault
• Vibrations produced is called an earthquake
• Earth’s crust movement causes the stresses applied

4. • Response of material to the arrival of energy
fronts released by rupture
• Two types:
• Body waves
• P and S
• Surface waves
• R and L

5. • Body waves
• P or primary waves
• Fastest waves
• Travel through solids,
liquids, or gases
• Compression wave,
material movement is
in the same direction as
wave movement
• Energy waves that
cause rocks to move
back and force in the •
same direction •
• Compression and
stretching forces are
created

6. • S or secondary waves
• Slower than P waves
• Travel through solids
only
• Shear waves - move
material perpendicular
to wave movement
• Energy waves that
cause rocks to move at
right angles to the
wave

7. • Surface Waves
• Travel just below or along the ground’s surface
• Slower than body waves; rolling and side-to-side
movement
• Especially damaging to buildings
• Energy waves that move rocks in an elliptical motion

8. Seismic waves do not travel through earth’s surface at the same speed
Primary waves are the fastest
Surface waves are the slowest
• Earthquake focus
• Focus – the point in Earth’s
interior where the energy
waves are produced
• Seismic waves
• Seismic wave - the energy
waves that move outward from
the earthquake focus and make
the ground quake
• Epicenter
• The point on Earth’s surface
directly above the earthquake
focus

9. • Normal Fault
• Earth’s plates move
apart
• Movement of the plates
causes tension
• Rocks above the fault
surface move downward
in relation to the rocks
below the fault surface

10. • Reverse Faults
• Compression forces are
applied because Earth’s
plates are coming
together
• Causes rocks to bend
and break
• Rocks above the fault
surface are forced up
and over the rocks
below the fault surface

11. • Strike-slip Fault
• Earth’s plates move
sideways to one
another
• Creates a shear force
• Rocks on either side
of the fault surface
are moving past each
other without much
upward or downward
movement

12. • Seismograph stations
• Record the information
from the earthquake by
recording the different
types of waves as they
reach the station

13. • Epicenter Location
• If information is received
from the earthquake at
three stations, then the
epicenter can be located
• A circle is drawn around
each station on a map
• The radius is equal to the
distance from the station
to the epicenter
• The point in which all
three circles intersect is
the earthquake epicenter

14. • Seismology
• Seismologists - People who study earthquakes and seismic
waves
• Use instruments called seismographs
• Record seismic waves
• A drum with a sheet of paper vibrates and a stationary
pen marks the vibrations on the paper
• The height of the lines are used to measure the energy
released from the earthquake called the magnitude

15. • Earthquake Magnitude
• Usually determines the strength of the break
• Doesn’t determine the duration or the size
• For each increase of 1 is 10 times stronger
• An earthquake of 4 is 10 times stronger than an earthquake
of 3
• Caused by the movement of the ocean floor
• Causes a disruption in the water
• Some are so wide that a large ship can travel over the wave
without knowing
• Recent earthquake in the Indian Ocean created a tsunamis
that was 100 feet high and moving at 500 mph

16. • Shaking and Ground rupture
• Shaking and ground
rupture are the main
effects created by
earthquakes, principally
resulting in more or less
severe damage to
buildings and other rigid
structures.

17. • The severity of the local effects depends on the complex
combination of the earthquake magnitude, the distance
from the epicenter, and the local geological and
geomorphologic conditions, which may amplify or reduce
wave propagation.
• The ground-shaking is measured by ground acceleration.

18. • Landslides and avalanches
• Earthquakes, along with
severe storms, volcanic
activity, coastal wave
attack, and wildfires, can
produce slope instability
leading to landslides, a
major geological hazard.
• Landslide danger may
persist while emergency
personnel are attempting
rescue.

19. • Fires
• Earthquakes can cause fires
by damaging electrical
power or gas lines. In the
event of water mains
rupturing and a loss of
pressure, it may also become
difficult to stop the spread of
a fire once it has started.
• For example, more deaths
in the 1906 San Francisco
earthquake were caused by
fire than by the earthquake
itself.

20. • Soil liquefaction
• Soil liquefaction occurs
when, because of the
shaking, water-saturated
granular material (such as
sand) temporarily loses its
strength and transforms
from a solid to a liquid.
• Soil liquefaction may
cause rigid structures, like
buildings and bridges, to tilt
or sink into the liquefied
deposits.

21. • This can be a devastating effect of earthquakes. For
example, in the 1964 Alaska earthquake, soil liquefaction
caused many buildings to sink into the ground, eventually
collapsing upon themselves.

22. • Tsunami
• Tsunamis are long-
wavelength, long-period sea
waves produced by the sudden
or abrupt movement of large
volumes of water.
• In the open ocean the
distance between wave crests
can surpass 100 kilometers
(62 mi), and the wave periods
can vary from five minutes to
one hour.

23. • Such tsunamis travel 600-800 kilometers per hour (373–497
miles per hour), depending on water depth.
• Large waves produced by an earthquake or a submarine
landslide can overrun nearby coastal areas in a matter of
minutes.
• Tsunamis can also travel thousands of kilometers across open
ocean and wreak destruction on far shores hours after the
earthquake that generated them.

24. • Floods
• A flood is an overflow of
any amount of water that
reaches land.
• Floods occur usually when
the volume of water within a
body of water, such as a
river or lake, exceeds the
total capacity of the
formation, and as a result
some of the water flows or
sits outside of the normal
perimeter of the body.

25. • However, floods may be secondary effects of
earthquakes, if dams are damaged.
• Earthquakes may cause landslips to dam rivers, which
collapse and cause floods.

26. • Human impacts
• An earthquake may cause
injury and loss of life, road and
bridge damage, general
property damage (which may
or may not be covered by
earthquake insurance), and
collapse or destabilization
(potentially leading to future
collapse) of buildings.
• The aftermath may bring
disease, lack of basic
necessities, and higher
insurance premiums.

27. • Seismic safe structures
• Structures that are resistant to the vibrations of Earth’s
crust
• Structures are made with moorings
• Made of steel and are filled with alternating layers of
rubber and steel
• These structures absorb the energy produced from the
earthquake

30. Damage in Oakland, CA, 1989
• Building
collapse
• Fire
• Tsunami
• Ground failure