The document discusses five methods to reduce the impacts of earthquakes: 1) Planning infrastructure locations away from quake-prone areas, 2) Designing quake-resistant buildings using techniques like base isolators and shear walls, 3) Strengthening existing structures by adding steel frames, 4) Providing education through drills and signs, and 5) Monitoring earthquakes using seismometers to warn people of impending quakes and allow for evacuation. Each method is described along with examples and limitations. The overall message is that a variety of approaches can help mitigate earthquake damage by considering location, design, reinforcement, preparedness, and early warning systems.

1. Methods to Reduce the
Impacts of Earthquakes

2. In this lesson, you will understand that:
• Various Methods can be used to Reduce the
Impacts of Earthquakes
1. Planning the Location of Infrastructure
2. Designing Earthquake Resistant Infrastructure
3. Strengthening Existing Infrastructure
4. Education
5. Earthquake Monitoring and Warning Systems

3. Problem:
The collapse of infrastructure causes much
economical damage and even deaths!

4. Solution/Method/Measure/Adaptation:
1. Planning the location of infrastructure
• Build new infrastructure away from earthquake
prone areas to reduce economical damage and
lower number of deaths caused by earthquakes
• Authorities can implement guidelines on the
location of new infrastructure and set limits on
the heights of buildings

5. Buildings are not too tall in
earthquake-prone Japan!

6. Example:
• In USA, authorities use earthquake risk maps to
control land use so as to minimise damage that
may be caused by earthquakes

7. Limitation:
• The control of land use is difficult in cities of
developing countries where there is high rural-
urban migration and the country lacks resources
to improve the situation
• Poverty causes such migrants to construct their
houses illegally on earthquake-prone zones, where
they may suffer devasting effects of earthquakes

8. Imagine the damage that earthquakes
can cause to these slums in Mumbai!

9. What is so
special about this
building in
Japan?

10. Solution/Method/Measure/Adaptation:
2. Designing Earthquake-Resistant Infrastructure
• New infrastructure can be specially designed to
withstand strong tremors by making use of the
latest technology

11. Earthquake Resistant Building
Cross-bracing
Shear walls
Reinforce walls
(concrete walls
using two steel
with steel bars
beams
in them) to
reduce rocking
Shock absorbers movements
(base isolators)
absorb tremors
of earthquakes

12. The Transamerica
Pyramid in San
Francisco cost S$75
million to build!

13. Limitation:
• People living in LDCs cannot afford to construct such
expensive earthquake resistant infrastructure

14. Problem:
There are still more than 1.8 million older
buildings that cannot withstand
earthquake tremors in Tokyo

15. Solution/Method/Measure/Adaptation:
3. Strengthening Existing Infrastructure
• New infrastructure can be specially designed to
withstand strong tremors and reduce damage
from earthquakes by making use of technology

16. Example:
• Existing infrastructure can
be reinforced by wrapping
steel frames around the
pillars of buildings and
bridges, or by placing steel
rods in existing structures

19. Example:
• Fireproof materials and automatic shut-off valves
can be installed into gas pipes and electricity
supplies to minimise the risk of fires in the event
of an earthquake

20. Limitation:
• The effectiveness of seismic retrofitting is limited
as the strengthened infrastructure may not be as
strong as new earthquake resistant infrastructure

21. Example of Limitation:
• During the 1994 Northridge Earthquake in USA,
many buildings and highways that had been
strengthened with steel frames were badly
damaged
• However, new earthquake-resistant buildings in
the same area remained undamaged
Watch Quakewrap!

22. Solution/Method/Measure/Adaptation:
4. Education on Emergency Procedure
• Earthquake drills are conducted regularly in
many earthquake-prone countries to educate
and familiarise people on what to do in the
event of an earthquake

23. • Governments of earthquake-prone countries
also use posters and signs to warn people about
areas that are prone to the effects of
earthquakes e.g. coastal areas where tsunamis
can occur
Watch TillySmith!

24. Drills are boring.

25. Limitation:
• People tend to be complacent and may not see
the importance of earthquake education
especially if earthquakes have not happened in
the region for a long time

26. Example of Limitation:
• Research shows that residents in Tokyo are less
prepared for earthquakes than residents in other
parts of Japan as the last Tokyo earthquake
occurred more than 80 years ago in 1923

27. Solution/Method/Measure/Adaptation:
5. Earthquake Monitoring and Warning Systems
• Earthquake-prone areas should invest in
seismometers and computers that can monitor
tremors of the Earth or change in water levels
• Authorities will then inform residents through
sirens or public broadcasts of impending danger
and begin mass evacuation

28. Example:
• In Haicheng, China, scientists identified changes in
the ground level and increase in small tremors
which are signs of an impending earthquake
• Authorities were informed and people were
warned to evacuate the city
• 90 000 people were saved from the magnitude 7.3
earthquake that destroyed 90% of the city’s
infrastructure

29. Tsunami Monitoring
and Warning
System

30. Limitation:
• The effectiveness of an earthquake monitoring
and warning system is limited
• Authorities may choose to ignore warnings to
avoid disruptions to business and tourism as
• Predictions of scientists may not always be
accurate and turn out to be false alarms

31. In this lesson, you have understood that:
• Various Methods can be used to Reduce the
Impacts of Earthquakes
1. Planning the Location of Infrastructure
2. Designing Earthquake Resistant Infrastructure
3. Strengthening Existing Infrastructure
4. Education
5. Earthquake Monitoring and Warning Systems