Earthquake-causes and effects

1. EARTHQUAKE
Earthquake - quake, tremor or temblor
is the result of a sudden release of energy in the
earth’s crust.

2. • Focus – Point of origin of earthquake
• Epicentre – Point just above the focus on the
surface of the earth

3. Seismograph
• Used to measure the magnitude of the
earthquake
• Richter scale
Intensity of earthquake measured on the basis
of

4. Characteristics of earthquake of
different magnitude
Richter Scale Effects
1 -3 Don’t feel the tremors
3 -4 Tremors felt
4 -5 Small objects fall
5 -6 Damage to weak building
6 - 7 Strong tremors over vast area
7-8 Lot of destruction over large areas.
8-9 Severe , strong tsunamis
9 and above Very intense, very rare

5. Earthquake waves
PRIMARY WAVES
- Very fast through solids, very slow
through liquids

6. SECONDARY WAVES
- Move only through solids
- reach the epicentre following the
primary waves

7. SURFACE WAVES
- Reach the epicenter last
- travel through the surface of the earth
- cause destruction on the earth’s
surface

8. CONSEQUENCES
• BUILEDING COLLAPSE
• HUMAN LIFE LOSS
• PROPERTY LOSS
• ANIMAL AND VEGETATION LOSS
• TSUNAMI

9. Precautions
• There should be earthquake surveilliance
centres
• People should be warned promptly about
possible earthquakes
• Give preference to constuction technology