1. Earthquake Destruction and Dangers

2. Major causes of earthquake damage
Soil conditions
Aftershocks
Tsunamis

3. Soil conditions
Layers of loosely packed soil, high in moisture can lead to
Landslides
Liquefaction

4. Landslides
Landslides are movement of material down a slope. They can occur…
when filled land is shaken violently
where steep slopes are found

6. Liquefaction Loosely packed soil turns into mud.
Most likely to occur in soil saturated with water.

7. Liquefaction Loosely packed soil turns into mud.
Most likely to occur in soil saturated with water.

8. Aftershocks
Smaller earthquakes that occur after a larger earthquake in the same area
They can occur hours, days, or months later
Buildings already weakened by the original earthquake can topple during aftershocks

10. Tsunamis A wave set off by an underwater earthquake
Earthquake jolts the ocean floor; pushes water out of the way
Displaced water forms large waves (tsunamis)
In the open ocean, height of wave is not significant
As the wave gets closer to land, water gets more shallow, pushes up into a tall wall ≈100 ft
YouTube:
Tsunami
Animation
YouTube:
CBS News
Asian Tsunami

15. http://news. nationalgeographic

16. http://www. dailymail. co

18. How do we prepare? Base-isolated buildings
Buildings rest on shock absorbing springs that allow the building to move without violently shaking

20. Protecting Structures

21. How do we prepare? Base-isolated buildings
Buildings rest on shock absorbing springs that allow the building to move without violently shaking
Warning systems
Monitoring faults and waves

22. Instruments for monitoring faults
Faults & Earthquakes
Creep meter
measures HORIZONTAL movement along a fault line through movement of a wire across the fault
Tiltmeter
measures VERTICAL movement, works like a carpenter’s level
Satellites
Measure VERTICAL changes in the distance between the satellite and ground

23. Fault monitoring instruments
Creep meter
Tiltmeter

24. Instruments for monitoring tsunamis
Tsunami detection buoys
39 stations collect seafloor height, temperature, pressure
Warning centers
If a tsunami is generated, they issue advisories, watches and warnings