volcano hazards

volcanoes

are opening in the earth’s crust that allows the energy from the interior of the earth to escape the surface

the energy from the magma

composed of molten rocks from the earth’s mantle that goes out in the form of lava, ash, and gas

pacific ring of fire

home of 75% of volcanoes

more than 20

how many active volcanoes in the country are active the last 600 years?

Philippine Institute of Volcanology and Seismology

what does PHIVOLCS mean?

potential volcano related hazard

are volcano-related phenomena that pose potential threat or negative impact to life, property, and the environment in a given period of time

lahar

• an indonesian term for the mixture of water, pyroclastic materials, and rock fragments flowing down a volcano or river valley

• it is highly destructive to anything on its path

ash fall

• this is composed of bits snd pieces of pulverized rock, minerals, and volcanic glass generated from the volcanic eruption

• it is usually spewed out from explosive eruptions when dissolved gases in magma expand and go out violently into the atmosphere

• the impact from the released gas shatters the magma and is forced out into the atmosphere where it hardens into fragments of volcanic rock and glass

2 mm or 0.079 inches

size of fragments from an ash fall

pyroclastic flow

• this refers to fast-moving fluidized mass of rock fragments and gases

• it maintains a very high temperature, burning everything in its path

• this can easily incinerate, burn, and suffocate humans and animals

• this may cause explosion or acid rain

1991

when did the mt. pinatubo erupted?

750 degrees celsius

what is pyroclastic flow temperature of mt. pinatubo eruption?

hot gas, steam, ash, and rock

what materials is pyroclastic flow made out of?

ballistic projectile

• this is a rock fragment that is ejected from a volcano during its explosive eruption

• it is like a cannonball that travels fast in the air

• according to usgs, this can be bombs and blocks

• can travel as far as 5km or even further depending on the magnitude of explosion

block

a projectile or rock fragment that is solid when ejected

bomb

a projectile or rock fragment that is launched in partially molten or molten state

united states geological survey

usgs means

volcanic gas

• this consist of sulfur dioxide and hydrogen sulfide which are poisonous and hazardous to organisms

• these are the main constituents of magma that is spewed out during an eruption

• the excessive composition of these chemicals in the air can cause acid rain

• plants, buildings, and other structures that are exposed to acid rain are prone to corrosion

• this can cause respiratory problems and other health risks

lava flow

• is a molten rock that pours down from the slopes of the volcano

• it is different from pyroclastic flow because it is denser and it moves slowly

• it gives more time for animals and humans to move away its path

• this can kill vegetation and destroy property by burning homes and destroying infrastructure

• it can ignite forest fires

tilting

deformation in the ground manifested by changes in ground elevation

ground fissuring

formation of cracks or openings

signs of an impending eruption

• occurrence of tremors or increase in the frequency of small earthquakes

• deformation in the ground manifested by changes in ground elevation (tilting) and formation of cracks or openings (ground fissuring). all these observations can support the speculation that rocks are being pushed upward and out of the crater of the volcano

• increase in the amount of volcanic gases and in temperature, which may indicate that the magma has gone closer to the surface.

• glow of volcanic crater due to the presence of magma.

• increase in steam emission coming from volcanic openings, fissures, or hot springs.

• thermal changes within the surroundings of the volcano.

• change in the color of nearby vegetation and lakes (the color changes in vegetation and lakes are due to the dissolution of minerals and other acidic chemicals from the volcano that found their way into these open areas.

• landslides and rockfall not due to heavy rains.

• drying up of springs and freshwater sources around the volcano.

precautionary safety measures before an eruption

1. stay updated with the local news.

2. learn about your community warning systems and emergency plans. Have a meeting with all family members and make family emergency preparedness plan. make sure that each member is well informed of your plan and he or she knows where the emergency supply kit is

3. prepare an emergency supply kit that should include the following: first-aid kit, clean clothes, food and water, flashlight with extra batteries, battery- operated radio, prescribed medicines, dust masks, goggles, and sturdy shoes.

4. pack all important and essential items in light and waterproof containers.

5. secure livestock in enclosed shelters.

6. listen to public safety announcements of local authorities. Follow the authorities' instructions if they tell you to evacuate the area.

precautionary safety measures during an eruption

1. follow evacuation orders issued by local authorities and remind family members of your disaster plan. Stay in the evacuation center until further instructions are given by authorities.

2. if told to stay indoors, place a damp cloth over your windows and, if possible, over your doors. make sure all windows, doors, and other vents are kept closed to prevent entry of ash and other materials spewed out by the volcano. the wet cloth will help keep fine volcanic particles from entering your house.

3. wear long-sleeved shirts and long pants.

4. use goggles to protect your eyes.

5. use a dust mask or hold a damp cloth over your face to prevent inhalation of ashes and other volcanic particles. this will also help you breathe easier.

6. avoid low-lying regions and river areas near the volcano. Volcanic debris and ash will be carried by the wind and gravity.

7. listen to a battery-operated radio for the latest emergency information.

8. prepare an emergency supply kit that should include the following: first-aid kit, clean clothes, food and water, flashlight with extra batteries, battery- operated radio, prescribed medicines, dust masks, goggles, and sturdy shoes.

9. pack all important and essential items in light and waterproof containers.

10. secure livestock in enclosed shelters.

11. listen to public safety announcements of local authorities. follow the authorities' instructions if they tell you to evacuate the area.

precautionary safety measures after an eruption

1. wait for the announcement from local authorities that it is safe to return to your house.

2. inspect your house carefully for any damage before you enter it. do not enter your house if you smell gas, lahar is present, or authorities have declared it unsafe.

3. if you or a family member has a respiratory ailment such as asthma or bronchitis, stay away from volcanic ash fall areas. volcanic ash can cause severe damage to the respiratory system as well as irritation to the skin and the eyes.

4. wear a dust mask, gloves, and goggles while cleaning the debris and ash fall on the roof of your house to avoid further damage.

5. check electrical wirings, appliances, and gas tanks before using them.

6. boil water before drinking it. groundwater pipes may have been contaminated by volcanic particles.

7. stay informed and listen for emergency updates and news