This document summarizes key information about earthquakes, including what they are, how they form, how they are classified, their effects, and how they are located. Earthquakes are caused by the sudden release of energy stored in rocks beneath the earth's surface. They originate at a focus and the point on the surface directly above is called the epicenter. Earthquakes are classified based on their cause, depth, and magnitude or intensity. Their location can be triangulated using data from multiple seismometers.

3. What we will study:-
• What is earthquake?
• How it forms?
• Classification of earthquake
• Effects
• Distribution of An earthquake
• Sesmic zone of India.
• How to locate an earthquake

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5. • An earthquake is a certain and temporary vibration
set up on earth🌎 surface due to sudden release of
energy stored in rocks beneath the earth surface.
• Earthquake usually last for few seconds to a minute
Earthquake:-

6. Focus:-The point of origin of an
earthquake within the earth
crust is known as focus
(hypocenter).
Epicenter:- The point lying vertically
above the earth surface
directly above the focus,
is known as Epicenter.

9. Sesmic waves:-
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⩥ Body wave:-
1. P-wave(Longitudinal
wave)
2. S-wave(Transverse
wave)
⩥ Surface waves:-
1. L-wave(Love
wave)
2. R –wave
(Rayleigh wave)

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11. Classification of earthquake:-
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Earthquake are generally classified
on the following basis.
1. Causes of an earthquake
2. Depth of focus
3. Intensity and magnitude of
earthquakes

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In 1906 H.F.REID
SENSE FRANSICO
examine that
displacement
of the ground
surface about San
Andreas fault

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Non –tectonic causes:-
• Surface causes
• Volcanic causes
• Collapse of subterrain
cavities

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Depth of focus:-
On the basis of depth of the focus the earthquakes are
divided into following groups.
1. Shallow focus earthquake(0-70km
deep)
2. Intermediate type earthquake (70-
300km)
3. Deep focus earthquake (300-
700km)

17. Intensity:-
Intensity of an earthquake is measure the
degree of damage &destruction it can
cause.
• Rossi–Forel scale
• Mercalli Scale
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18. Earthquake magnitude scale:-
• Magnitude is the measure of
energy release during the time of
earthquake.
• The scale which indicate the
magnitude of earthquake is
known as richter scale

19. Richter scale:-
• Professor Charles Richter to the California
Institute of technology prposed a scale of
earth’s magnitude in 1935 to indicate the
quantity of energy increased by a single
earthquake
• This is a numerical scale of magnitude from 0
to 9 with the higher number indicating larger
earthquake.
• This scale is commonly known as richter
scale. Professor
Charles Richter

20. “
Seismometers-The measurement
of Earthquake
Seismometers are instruments that
measure motions Of the
ground, including those of seismic
waves generated by earthquakes,
volcanic eruptions and other seismic
sources..
Seismometers may be deployed at Earth's
surface, in shallow vaults, in boreholes, or
underwater.

21. Divided into 2
types:-
•Primaryeffects
•Secondaryeffects

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Primary effect:-
• Creation of slope and fissure
development
• Wrapping of strata
• Origin of new springs and creatiom
and sand dyke

23. Secondary effect:-

24. Tsunami:-
Floods:-

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Distribution of an earthquake:-
• The earthquakes are distributed unevenly on the globe.
• In certain places they are more frequent and in some place they
are highly noticeable.
• It has been observed that most of the earthquakes are originated
within 3 belt;
• The circum-pacific belt
• Mediterranean
himalayan belt
• Minor belt

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33. Earthquake prediction
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Earthquake prediction is usually defined as the specification of the time,
location,and magnitude of a future earthquake within stated limits.
But some evidence of upcoming earthquake are following;-
• Unusual animal behavior
• water level in wells
• Large scale of fluctuations Of oil flow from oil wells.
• Foreshocks or minor shocks before major earthquake
• Temperature change
• Uplifting of earth surface
• Change in seismic wave velocity

34. How to locate an earthquake:-
⩥ Triangulation can be used to locate an
earthquake.
⩥ The seismometersare shown as
green dots.
⩥ The calculated distance from each
seismometers to the earthquake is
shown as a circle.
⩥ The location where all the circles intersect is the
location of the earthquake epicenter.
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