Created by: Karl Ruelan; Philippines (c) David G. Educational Purposes Only For Science - 11 Presentation; 8/30/16 About Natural Hazards Specifically: Earthquake and Volcanic Hazards It also includes: Mitigation and Adaptation to this hazards. Powerpoint What is Earthquake? The minimal to rapid shaking of the ground due to the movement of rocks along fractures known as faults. Earthquake Hazards Surface Rupture & Physical Damage Liquefaction Fires Tsunami Landslide Volcanic Hazards Pyroclastic Flows and Materials People unable to run Bury people and agriculture Mudflow or LAHAR Poisonous gases Tsunami Volcanic Eruption Two Types; based on magma comp. Explosive Eruption Non-Explosive Eruption HAZARD MAPS One of the government’s response to mitigate and adapt to the hazards. Developed to indicate the places where most of the natural disasters usually occur and will most likely occur. by the shaking itself or by the ground beneath them settling to a different level than it was before the earthquake (subsidence) or (uplift). Subsidence is the motion of a surface (usually, the Earth's surface) as it shifts downward relative to a datum such as sea-level.  A fault is a fracture or zone of fractures between two blocks of rock. Faults allow the blocks to move relative to each other. Philippines experience a lot of Earthquakes because it is located in the Circum-Pacific Belt, situated in the Pacific Ring of Fire Pacific Ring of Fire is term used for VOLCANOES only.

1. NATURAL HAZARDS
Earthquake and Volcanic

3. The minimal to rapid shaking of the ground due to the movement of rocks
along fractures known as faults.

4. EARTHQUAKE
HAZARDS

5. There are so many things that can happen
during or after an earthquake
Specifically disasters or ‘hazards’
WHAT ARE THOSE?

6. SURFACE RUPTURE AND PHYSICAL DAMAGE
• Is the most obvious hazard of an Earthquake
• Breaking of the ground, (Uplift and Subsidence); and
• Buildings collapsing
Earthquakes with higher energy create stronger ground motion

7. LIQUEFACTION
• Is the mixing of sand or soil and groundwater (underground water) during the
shaking of an Earthquake.
• Buildings can even sink into the ground if soil liquefaction occurs.
It is a hazard specially in areas that have groundwater near the surface and sandy soil
Liquefaction
+
Subsidence

8. HOW DOES
HAPPEN?

9. • When the water and soil are mixed, the ground becomes very soft and
acts similar to quicksand
If liquefaction occurs under a building, it may start to lean, tip over, or sink several feet.
• The ground firms up again after the earthquake has past and the
water has settled back down it usual place deeper in the ground.

10. • It can break out during or after an earthquake when damage happen along electric
power lines, substations, and power plants.
Fire after earthquake in Biratnagar, Nepal
• It can also occur when Ground Rupture creates gas leaks

11. • Also called harbor wave, is an earthquake hazard that is generated when
earthquakes occur on the seafloor.

12. • Occurs when there is too much shaking of the ground, which loosens the soil,
facilitating its downward movement.
Landslide may occur as a result of broken off pieces of land.

13. Most of the hazards to people come from man-made structures
themselves and the shaking they receive from the earthquake. The real
dangers to people are being crushed in a collapsing building, drowning
in a flood caused by a broken dam or levee, getting buried under a
landslide, or being burned in a fire.
Although landslide is an Earthquake hazard, it could also be triggered by other factors
such as heavy rainfall, deforestation, human activities, and etc.

14. VOLCANIC
ERUPTIONS
+ HAZARDS

15. QUICK FACT
Earthquakes are sometimes used in predicting
volcanic eruptions
It alerts the authorities to observe a nearby volcano.

16. Active volcanoes are the ones that are usually closely monitored by Volcanologist.
Two types of
*Depending on the magma composition.

17. BASED ON MAGMA COMPOSITION
Explosive Type
• Highly viscous magma
• Contains large amounts of dissolved
gases.
Hawaiian / Non-Explosive Type
• Low viscous magma
• Contains low amount of dissolved gases.
Magma could not easily get out, that’s why it
builds up pressure resulting to an explosion.

18. VISCOSITY?

19. Viscosity determines the ability of magma to flow
The lower viscosity, the easier it is for the magma to flow.
• The viscosity of magma is affected by and
Silica
Content
Temperature
Silica
Content Temperature
High Viscosity Low Viscosity
Explosive Type Non-Explosive Type

20. Explosive volcanic eruptions release pyroclastic flows and materials that are
considered to pose the greatest threat.
• Pyroclastic flows often render people unable to run since they become overwhelmed with what
they are seeing.
Pyroclastic Flow
• Too much pyroclastic material, may bury people and severely damage the
agricultural land and livestock; and somehow lead to FAMINE.

21. • After an eruption, pyroclastic material that have settled along the slope of the
volcano get mixed with rainwater… Starting a mudflow or LAHAR.
Lahar moving at high speed and destroying everything along its path.
• Poisonous gases are also released by volcanoes.
• Volcanic eruption can also happen underwater, which can trigger a

22. Earthquake Hazards
Volcanic Eruption + Hazards
Earthquake Hazards
Surface Rupture & Physical Damage
Liquefaction
Fires
Tsunami
Landslide
Volcanic Eruption
Two Types; based on magma comp.
1. Explosive Eruption
2. Non-Explosive Eruption
Volcanic Hazards
Pyroclastic Flows and Materials
People unable to run
Bury people and agriculture
Mudflow or LAHAR
Poisonous gases
Tsunami

23. MITIGATION
AND
ADAPTATION

24. MITIGATION
Is the effort to reduce loss of life and property by lessening the impact of disasters.
• In order for mitigation to be effective, we need to take action now before the next
disaster – to reduce human and financial consequences later.
ADAPTATION
Is to reduce our vulnerability to the harmful effects of natural disasters.
• Adapting to life in case of disasters involves adjusting to actual or expected future disasters.

25. The Philippines is located in a disaster risk area, and hazards will always be present.
HAZARD MAPS
• One of the government’s response to mitigate and adapt to the hazards.
• Developed to indicate the places where most of the natural disasters usually occur
and will most likely occur.
With this, people can be informed and can create an emergency response plan.
There can be reduction and mitigation of the dangers of these natural disasters to life and property
Flood Hazard Map in Marikina Earthquake Hazard | Risk in MM

26. Aside from Hazards Maps to mitigate and adapt to natural disasters,
Action plans should be conceptualized to identify the priorities for action and plan
for the possible impacts affecting the country.
Local Programs should also be established to help the people who are most affected
by natural disasters to recover from their losses and also train them think out of the
box.
Education | Knowledge is also a means for people to mitigate and adapt to
natural disasters.

27. In preparation for natural disasters, information regarding what to do before, during,
and after a natural disaster is disseminated all over the country.
Before During After
Be aware of the earthquake
evacuation plans for all the
buildings you occupy regularly
Duck under a sturdy desk
or table and hold onto it.
Protect your head with
your arms.
Check yourself and
others for injuries.
Before During After
Prepare an emergency
disaster plan for you and
your family
Do not panic; stay calm. Check your house for
damage.
Before After
Be aware of landslide-susceptible areas
in your neighborhood.
Stay away from the slide area since the
land may still be loose and it may still
occur.
Earthquake
Landslide
Volcanic
Eruption

28. END OF PRESENTATION

29. INDEX
• by the shaking itself or by the ground beneath them settling to a different level than
it was before the earthquake (subsidence) or (uplift).
• Subsidence is the motion of a surface (usually, the Earth's surface) as it shifts
downward relative to a datum such as sea-level.
• A fault is a fracture or zone of fractures between two blocks of rock. Faults allow the
blocks to move relative to each other.
• Philippines experience a lot of Earthquakes because it is located in the Circum-
Pacific Belt, situated in the Pacific Ring of Fire
• Pacific Ring of Fire is term used for VOLCANOES only.

30. TWO TYPES OF VOLCANO
• The viscosity of the magma is affected by Silica content and temperature
HAZARD MAPS
• The Department of Environment and Natural Resources (DENR) are responsible for
Hazard Maps.
INDEX