Geologically active faults within 50 to 500km distance from Dhaka. Dhaka is among the 20 major world cities that are the greatest risk from earthquakes. Some of these earthquakes especially the 1762, 1812, 1865, 1885 and 1897 happened in Dhaka. If 7-8 grade in Richter Scale earthquake happen in Dhaka 70-80 percent concrete structures would just collapse and 30,00,000 peoples will die.

1. Department:- Civil
Year:- 4th year(2nd sem)
Submitted To:
Dr. Abu Nasser Choudhury
Assistant Professor
Department of Civil Engineering
Submitted By:
Md. Moniruzzaman
Reg. No: 11205042

2. Earthquakes constitute one of the worst natural hazards
which often turn into disaster causing widespread
destruction and loss to human life.

3. Effect on earthquake
The effects of earthquake vary upon the magnitude
and intensity. Earthquakes occur every now and then
all round the world, except in some places where
earthquakes occur rarely. The devastation of cities and
towns is one of the effects of earthquake.

4. What is Earthquake?
An Earthquake is the result
of a sudden release of energy
in the earth’s crust that creates
seismic waves.
The seismic activity of an
area refers to the frequency,
type and size of earthquakes
experienced over a period of
time

5. For example:
If you throw stone in a
pond of still water,series of
waves are produced on the
surface of water,these waves
spread out in all directions from
the point where the stone strikes
the water.
similarly, any sudden
disturbances in the earth’s crust
may produce vibration in the
crust which travel in all direction
from point of disturbances.

6. How does an earthquake happen?
There are about 20 plates along the surface of the
earth that move continuously and slowly past each
other. As the plates move they put forces on
themselves and each other. when the force is large
enough, the crust is forced to break. When the break
occurs the stored stress is released as a form of wave
and makes the ground shake.

7. Focus(Hypocenter):
Focus is the point on the fault
where rupture occurs and the
location from which seismic
waves are released.
Epicenter:
Epicenter is the point on the
earth’s surface that is directly
above the focus ,the point where
an earthquake or underground
explosion originates.

8. Cont.…
Fault Line:
A Fault line is the surface trace of
a fault, the line of intersection
between the earth’s surface.
Fault plane:
Fault plane are the cracks or
sudden slips of the land .
Fault Scrap:
A Fault scrap is the topographic
expression of faulting attributed
to the displacement of the land
surface by movement along
faults.

9. The primary cause of an earthquake is faults on the crust of the earth.
“A Fault is a break or fracture b/w two blocks of rocks in
response to stress.”
This movement may occur rapidly, in the form of an
earthquake or may occur slowly, in the form of creep.
Earth scientists use the angle of the fault with respect to the
surface (known as the dip) and the direction of slip along the
fault to classify faults.

10. Classification Of Faults
Normal fault: Thrust (reverse)fault:
Strike-slip fault:Oblique fault:

11. Some major causes of earthquakes on basic of its causes are:
Surface causes
Volcanic causes
Tectonic causes

12. Seismic waves produced due to earthquake are basically divided into two
major types:
Body waves
Surface waves
1.Primary (P) waves
2.Secondary(S) waves

13. Bangladesh and Ganges Brahmaputra delta
lies at the junction of three plates: the Indian
plate, the Eurasian plate and the Burma platelet.
Bangladesh is bounded by the Shilling plateau
to the north, Indian shield to the west, the Indo-
Barman ranges to the east and Bay of Bengal to
the south that make the complex geographical
position.
Tectonic Position of Bangladesh

14. Cont.……

15. Cont.……
Indian plate is moving to the
northeast direction at the rate of
6cm per year and sub ducting
under the Eurasian plate and
Burmese plate at a rate of 45
mm and 35 mm per year
respectively that continues the
uplift of Himalayan Arc and
Indo-Barman Arch.
(source: Bangla
PIRE)

16. (Continued)……

17.  Zone 1:High Risk
Mymensing,Sylhet,Rangpur,La
lmonirhat, Kurigram etc.
 Zone 2:Moderate Risk
Bogra, Dinajpur, Dhaka,
Comilla, panchgar etc.
 Zone 3:Low Risk
Khulna, jessor, Barisal,
Patuakhali etc.
Earthquake zone of Bangladesh

18.  Geologically active faults within
50 to 500km distance from
Dhaka.
 Dhaka is among the 20 major
world cities that are the greatest
risk from earthquakes
 Some of these earthquakes
especially the 1762, 1812, 1865,
1885 and 1897 happened in
Dhaka. If 7-8 grade in Richter
Scale earthquake happen in
Dhaka 70-80 percent concrete
structures would just collapse and
30,00,000 peoples will die.
Earthquake and Dhaka City

19. Year Name Magnitude Distance from
Capital(km)
Affected Area
1869 Cachar
Earthquake
7.5 250 Assam,
Monipur, Sylhet
1985 Bengle
Earthquake
7.0 170 Jamalpur,
Mymensing,
Bogra
1897 Great Indian
Earthquake
8.7 230 Assam, Sylhet,
Rangpur
1918 Srimangal
Earthquake
7.6 150 Whole Sylhet
to Dhaka
1930 Dubri
Earthquake
7.1 250 Rangpur
1934 Bihar-Nepal
Earthquake
8.3 510 Nepal, India,
Bangladesh
1950 Assam
Earthquake
8.5 780 Assam, Whole
Bangladesh
Historical Earthquake in Bangladesh

20. Year Name Maqgnitude Distance from
Capital(km)
Affected Area
1987 Sylhet
Earthquake
5.6 200 Northern
Bangladesh
1997 Bandarban
Earthquake
6.0 325 South-eastern
part
1999 Maheskhali
Earthquake
5.1 350 Maheskhali
2003 Barkal
Earthquake
5.1 350 Barkal
2015 Nepal
Earthquake
7.9 745 Nepal, India,
Bangladesh
(Continued)…….

21.  The tectonic location
 The huge number of population
 The unplanned buildings over the city
 The week infrastructure
 The different types of faults
 Less consciousness of people
 Less planning of government
 Economical lacking
 Lack of land use planning
The Earthquake Risk of Bangladesh

22. Mitigation: Organization Involvement
• Ministry of disaster and management
• Institute of Earthquake Engineering
Research(IEER), Chittagong
• Dhaka University Earth and Observatory
Center
• Bangladesh Earthquake Society(BES)
• Geological Survey of Bangladesh(GSB)
• Action Aid Bangladesh(AAB)
• Bangladesh Concrete Society(BCS)