power point presentation

1. Kerala university COLLEGE of teacher education
2013-2014
MALU.G
REG:NO 13 983
018
SOCIAL SCIENCE

3. EARTHQUAKES

4. EARTHQUAKES
 The processes that take place in the interior of the
earth causes in the storage of energy in some
portions in the earth.
 Earthquakes occur on those instances when these
energy is being released.

5. The point of origin of the earthquakes is known as
focus
The point just above the focus on the surface on the
earth is known as epicenter
The energy being released from the focus
propagates as waves .
These cause tremors on the surface of the earth and
cause destructions.

6. The instrument used to measure
the magnitude of the earthquake is
called a seismograph.
The intensity of the earthquake is
measured based on the Richter
scale.

7. Earthquake- a view
SALIENT FEATURES OF EARTHQUAKE WAVES
 Primary waves move very fast through solids, and very
slowly through liquids.
 These waves reach epicenter from the focus first but
secondary waves moves only through solids. They do not
travel through liquids.
 These reach the epicenter following the primary waves.
 These two waves travel to the interior of the earth. So
they are known as body waves