How to combat EQ

1. Source: Kobe I EERI - Slide #43
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2. An earthquake is a violent
shaking of the earth’s crust due to
breaking and shifting of rock
beneath the earth’s surface.
Source: http://sorcerer.ucsd.edu/es160/lecture1/world_65_95_quakes.gif
Just the Facts……

3. arthquakes are the shaking, rolling or sudden shock of the earth’s surface.
Earthquakes happen along "fault lines" in the earth’s crust.
Earthquakes can be felt over large areas although they usually last less than
one minute.
Earthquake is essentially a sudden and transient motion or series of motions of
the earth’s surface
Earthquake originates in a limited underground region, due to disturbance of
the elastic equilibrium of the rock mass
Earthquakes cannot be predicted -- although scientists are working on it!
Most of the time, you will notice an earthquake by the gentle shaking of the
ground.
Earthquakes are sometimes called temblors, quakes, shakers or seismic
activity.
Before we move ahead…………………...
a few points to remember

4. IMPORTANT TERMINOLOGY
THE PLACE OF THE ORIGIN OF AN EARTHQUAKE IS
CALLED FOCUS WHICH IS ALWAYS HIDDEN INSIDE THE
EARTH BUT THE DEPTH OF WHICH VARIES FROM PLACE
TO PLACE
THE PLACE ON THE GROUND SURFACE WHICH IS
PERPENDICULAR TO THE ‘BURRIED’ “FOCUS” OR
“HYPOCENTER” RECORDING THE SEISMIC WAVES FOR THE
FIRST TIME IS CALLED EPICENTER.

5. AT THE JOINT OF TWO INTERACTING
PLATES THE ROCKS CRUSHED UNDER
GREAT STRESS CAUSING EARTHQUAKE
WAVES IN ALL DIRECTIONS

6. Causes
• Tectonic activity
• Volcanic activity
• Land-slides
• Bursting in mines
• Nuclear explosions

7. SEISMIC WAVES
• Body Waves
- Primary waves P-waves
- Secondary waves S-waves
• Surface waves
-Love waves
-Rayleigh waves

8. Primary waves
- Particle motion is in the same or opposite to the
direction of the wave propagation
Secondary waves
Particle motion within the transmitting medium is at right
angles to the direction of wave propagation

9. Love waves
Particle motion is horizontal.
Rayleigh waves
Particle motion is vertical and in the direction of propagation. No
transverse vibration.

10. • P WAVES ARE FASTEST
• FOLLOWED BY S WAVES, LOVE
WAVES AND RALEIGH WAVES
• S WAVES DO NOT TRAVEL THROUGH
WATER AND ARE MOST
DESTRUCTIVE IN TERMS OF
DAMAGE OF STRUCTURES
CHARACTERISTICS OF
SEISMIC WAVES

11. EARTHQUAKE MAGNITUDE
A MEASURRE OF THE SIZE
OF THE EARTHQUAKE OR
THE ENERGY RELEASED
• Need for the scale
• Richter scale in 1930

12. Earthquake Intensity
• Indicates the intensity of shaking or the
extent of damage
• De Rossi in Italy and Forel in Switzerland
proposed I to X Rossi-Forel scale.
• In 1902 Mercalli (Italy) revised it.
• MSK Scale
• JMA Scale

13. THE INTENSITY OF AN EARTHQUAKE
DEPENDS ON A VARIETY OF FACTORS
• MAGNITUDE
• DISTANCE FROM EPICENTER
• ACCELERATION
• DURATION
• AMPLTUDE OF WAVES
• TYPE OF GROUND
• WATER TABLE

15. Source: www.asc-india.org
Dip slip faults
-Normal
-Reverse
Strike slip
faults
-Right lateral
-Left lateral

16. PLATE BOUNDARIES
Transform plate
boundary
WHERE TWO PLATES
SLIDE PAST EACH
OTHER WITHOUT MUCH
DISTURBANCES.
Convergent plate
boundary
WHERE TWO PLATES
MOVE TOWARDS EACH
OTHER CAUSING ONE
PLATE TO SUBMERGE
BENEATH THE OTHER.
Divergent plate boundary
WHERE TWO PLATES
MOVE AWAY FROM
EACH OTHER.

17. San
Andreas
Fault
Mid Atlantic
Ridge

18. •A study on a
seismic fault that
passes through
Haryana, has shown
that the Indo-
Gangetic plain,
which covers parts
of Delhi, Uttar
Pradesh, Bihar, West
Bengal and Assam,
may be hit by big
quakes in future.

21. Seismic Zone
Map of India:
-2002
About 65 percent of
the land area of
India is liable to
seismic hazard
damage (about 26%
under MSK Intensity
VII, 18% under VIII
and 12% under IX
and higher).

22. Status of earthquake monitoring
• IMD is the nodal agency dealing with measuring
earthquakes in India.
• At present is maintaining a network of 51 seismological
observatories.
• During 1996-99, twenty-four seismological observatories
were upgraded with broadband digital seismographs.
• A Central Receiving Station (CRS ) and a National
Seismological Data Base Centre (NSDC) have been
established at New Delhi to receive analyze and
systematically archive the seismic data.
• Micro earthquake surveys for < 3 magnitude earthquakes.

23. EARTHQUAKES IN INDIA
Year Place of occurrence Magnitudes Destruction
1991 Uttarkashi 6.6 Almost 700 people died
and lots of damages to
roads and property
1993 Latur 6.4 About 8000 people died,
huge devastation in
Marathawada region in
Maharashtra
1997 Jabalpur 6.0 About 39people died, huge
damage in rural areas
1999 Chamoli 6.8 About 100 people died,
huge damage to property
2001 Bhuj 6.9 About 14000 people died,
devastating effect

24. Earthquake Vulnerability of West Bengal
•Earthquakes are fairly common in most
parts of the state but their frequency is
relatively low.
•Northern districts affected by large
earthquakes in the Sikkim Himalayas
•Also earthquakes in the Bangladesh border
region and the Ganga Delta
•State was severely
shaken in both the Assam
earthquakes and the
Bihar Nepal Earthquake

25. Seismic Hazard
• Western sections of the northern districts of
Jalpaiguri and Kooch Bihar lie in Zone V.
• The remaining parts of these two districts, along
with the districts of Darjeeling, Uttar Dinajpur,
Dakshin Dinajpur, Maldah, 24 North Parganas
and 24 South Parganas lie in Zone IV.
• The rest of the state along with the city of Kolkata,
lies in Zone III.
• Small part of Purulia, tip of Bankura and
Medinapur lies in Zone II.

26. Gujarat Earthquake

27. Mexico Earthquake
School Building

28. Poor reinforcement detailing

29. Large blocks piled up using weak bond

30. Soft bottom storey

31. Earthquake
Don’t Kill
People
but
Buildings Do

32. Strategies for Earthquake Vulnerability Reduction
1. Awareness generation
2. Development of Earthquake preparedness plans
3. Development of a techno-legal framework
4. Training and Capacity building
5. Networking knowledge of best practices

33. Earthquake Don’t Kill
People
but
Buildings Do
Earthquake Risk
•Hazard = Probability of ground motion
•Site effects = Soil properties, topography
presence of Reservoirs (RIS),
Mines (MIS)
•Vulnerability = Building types, Age
•Risk = Hazard x Site effects x Vulnerability

34. Earthquake Hazards
• Primary Hazards
• Secondary Hazards
- Extensive loss can be caused by the induced or
secondary hazards such as
• liquefaction
• tsunami
• Landslide
• Fire

35. Development of Earthquake
preparedness plans
•Identification of nodal agencies
•Meeting with line departments
•General Meeting with public of each ward
•Selection of two volunteers from the ward
•Orientation and training of volunteers
•Mapping by community with assistance of volunteers
–Social Mapping,Resource Mapping,Hazard Mapping,
Need Assessment
•Development of preparedness plan –ward, city level
•Formation of Task forces
•Development of an Incident Command System

36. Mitigation & Preparedness… for better response

37. Capacity building
Of Government engineers,practicing Architects,engineers,
resource institutions
o On codal provisions,safe construction practices, retrofitting
measures etc.
Of Development authorities, ULBs, Resource institutions,
Resident’s associations
o On awareness generation techniques,development of
Earthquake Preparedness and response plans
o Masons training for the construction of safe houses using cost
effective technologies
Of policy makers
– on regional vulnerability, development of the techno-legal
regime etc.

38. DURING THE EARTHQUAKE
INSIDE YOUR HOUSE ,PROTECT
YOURSELF UNDER TABLES,STRONG
HORIOZONTAL MEMBERS, ETC
IN OPEN AREAS ,STAY AWAY FROM
BUILDINGS,ELECTRIC WIRES AND POLES,
IN PUBLIC PLACES, STAY AWAY FROM NEON SIGNS,
WINDOWS AND DISPLAYS,
TRY TO REMAIN CALM AND HELP OTHERS.
AVOID THE USE OF LIFTS,
Drop, Cover Hold

39. CHECK YOURSELVES AND OTHERS FOR INJURIES,
ADMINISTER THE FIRST- AID QUIKLY AND CAREFULLY,
AFTER THE EARTHQUAKE
CHECK GAS, ELECTRICITY AND OTHER CONNECTIONS ,
TRY TO REMAIN CALM AND HELP OTHERS.
AVOID THE USE OF LIFTS,
CHECK THE STRUCTURE FOR STRUCTURAL DAMAGES AND
HAZARDS,
LISTEN AND FOLLOW THE RADIO BROADCAST, EMERGENCY
ANNOUNCEMENTS THROUGH MEDIA,

40. Let’s make a safer world