1. The document presents information about earthquakes, including their definition, causes, types, measuring scales, and effects. It discusses how earthquakes are caused by tectonic movements that release tension in the Earth's crust. 2. Earthquakes produce different types of seismic waves, including P waves, S waves, and surface waves. The Richter scale is used to measure the magnitude of earthquakes from minor to great. 3. Bangladesh is divided into three seismic zones - the northern, central, and southern regions - based on earthquake risks. Earthquakes can damage infrastructure and cause fires, floods, landslides and tsunamis. Safety tips are provided for both indoors and outdoors during an earthquake

1. A PRESENTATION ON
EARTHQUAKE
1

2. PRESENTED BY PRESENTED TO
MD. ASHIEK (337) MD. TITUMIR HASAN
PADMA PRANJAL DAS (319) LECTURER , DEPARTMENT OF
CIVIL ENGINEERNG
MYMENSINGH ENGINEERING
COLLEGE
2

3. CONTENTS
Definition.
Causes of earthquake.
Types of earthquake.
Waves of earthquake.
Measuring scale of earthquake.
Earthquake zone in Bangladesh.
Effect of earthquake.
Largest earthquake in world.
Earthquake safety.
Reference.
3

4. Definition of earthquake
• Earthquake is the shaking rolling or sudden shock of the earth’s
surface.
4

5. Sources of Earthquake
• Focus (Hypocenter)
-underground of earth where rock breaks
• Epicenter
-point above focus on earth
surface
• Seismic waves
-energy wave that travels from
the epicenter
5

6. Causes of earthquake
• Earthquakes are caused by tectonic movements in the Earth's crust.
• Earthquakes occur when tension is released from inside the crust.
• Earthquake energy is released in seismic waves.
• These waves spread out from the focus.
6

7. Types of earthquake
• On the basis of depth
1. Shallow earthquake.( 60 km )
2. Intermediate earthquake.( 60-300 km )
3.Deep earthquake.( > 300 km )
7

8. Waves of earthquake
• Seismic wave.
- body wave
1. Primary or P -wave.
- compression wave.
2. Secondary or S -wave.
- Transverse wave.
- Surface wave
8

9. Seismic
wave
• Seismic waves are the waves of energy caused by the sudden breaking of rock
within the earth or an explosion.
• which can be detected with a sensitive instrument called seismograph.
9

10. Body wave
P-Waves (compression wave)
1. The first wave to arrive at an earthquake.
2. This is the fastest kind of seismic wave.
3. The P wave can move through solid rock and fluids.
10

11. Body wave
S wave (transverse wave)
1. Moves the ground up and down or side to side.
2. Cause building damage, 4.5 km/sec.
3. which is the second wave we feel in an earthquake.
11

12. Surface Waves
• Move along the earth surface.
• Produce motion in upper crust.
• Travel more slowly than ‘ P ‘ and ‘ S ‘ waves.
• More destructive.
• Surface wave are divided into following types:
1. Love waves 2. Rayleigh waves
12

13. Measuring scale of earthquake
• Richter scale is the measuring scale of an earthquake.
GROUP MAGNITUDE
Great 8 and Higher
Major 7-7.9
Strong 6-6.9
Moderate 5-5.9
Light 4-4.9
Minor 3-3.9
Very Minor <3.0
13

14. Earthquake zone in Bangladesh
• Bangladesh are divided in three seismic zone.
1. Northern part including Rangpur, Mymensingh, Sylhet
2. Greater district of Dinajpur, Bogra , Dhaka and Chittagong
3. Southern part including Khulna , Barisal, Patuakhali.
14

15. Effect of earthquake
1. Ground shaking.
- Caused by passage of seismic wave.
2. Damage of man made structure.
- Damage of roads , bridges, dams and
buildings from ground motion.
15

16. Effect of earthquake
3. Fire.
- Occurs because of broken gas and electrical lines.
4.Tsunami.
- A series of waves caused by earthquake ,under
water volcanic eruption .
16

17. Effect of earthquake
5. Floods.
- caused by broken water lines , dams and
earthquake generated tsunamis.
6. Land slides.
-caused by ground vibration as well as
gravitational force.
17

18. Largest earthquake in world
18

19. Earthquake safety
• During an Earthquake – Indoors
1. Face Away from Windows.
2. Watch for Falling Objects.
3. Don’t use lift.
4. Take shelter under a table.
• During an Earthquake -outdoor
1. stay away from buildings.
2. stay away from fuel and gas lines.
3. In a moving automobile, stop as quickly.
4. Stay away from electric point and cable.
19

20. References
• https://en.wikipedia.org/wiki/Surface_wave
• https://www.thebangladesh.net/earthquake-maps-of
bangladesh.html
• http://www.bbc.co.uk/schools/gcsebitesize/geography/natural_h
azards/earthquakes_rev1.shtml
• https://www.britannica.com/science/earthquake-
geology/Shallow-intermediate-and-deep-foci
20

21. THANK YOU
21