An earthquake is the sudden
shaking of the earth which lasts for
a very short time.
An earthquake is caused by violent
movements of rocks deep inside
the earth’s crust.
A major earthquake can cause
damage to life and property on a
1) 26th Jan 2001 in bhuj district of Gujarat.
2) 8th Oct 2005 in Uri & tang Dhār towns
of north Kashmir.
1) 18th September 1737 in Kolkata in
2) 5th March 2012 in new Delhi.
Earthquakes can cause
immense damage to houses
people,etc.a lot of people get
killed when they get buried
under the debris of collapsed
houses and other buildings
during an earthquake.
Three layers of earth…
The inside of earth is made up of 3
main layers of earth known as:
1)Core: The innermost part of the
earth is known as core
2)Mantle: The central region of the
earth between the core and crust.
3)Crust: The outermost layer of earth
is called crust.
Why do they occur?
Earthquakes occur when the moving plates of the
earth’s crust :
1. Slide past one another
1. Collide with one another
The weak zones of earth’s
crust are called seismic zones
or fault zones. Most major
earthquakes occur in the well
defined seismic zones called
It is an instrument which measures and records the
magnitude of an earthquake in terms of the
shockwaves it produces.
Seismograph is also known as seismometer.
Focus and Epicenter
The place of origin of an earthquake
or moonquake is called focus.
The part of the earth's surface that is
directly above the place where an
earthquake starts is called an
An open-ended logarithmic
scale for expressing the
magnitude of an earthquake.