I Can Survive GeoHazards
  Volcanic Hazards
 
RISK TO VOLCANIC ERUPTIONS

Philippines lies within the Ring of Fire, a region of subduction zone volcanism surrounding the Pacific Ocean. This explains the distribution of most volcanoes in the Philippines. In 1991, Mt. Pinatubo eruption was well known to be the most violent eruption in the 20th century. Philippine Volcanoes are classified as Active, Inactive and Potentially active. Twenty-two (22) historically active volcanoes are distributed all over the archipelago.

Risk to Volcanic Eruptions

Risk to Volcanic Eruptions

Since volcanoes are not present in some provinces, these particular areas have no risk to volcanic eruptions. The top ten provinces at risk are:

  1. Camiguin
  2. Sulu
  3. Biliran
  4. Albay
  5. Bataan
  6. Sorsogon
  7. South Cotabato
  8. Laguna
  9. Camarines Sur
  10. Batanes

Camiguin has the highest risk because the land area is so small such that a volcanic eruption can affect the whole province. Sulu ranked second because it has the most number of active and potentially active volcanoes.





What to do before an eruption

  1. Make evacuation plans. If you live in a known volcanic hazard area, plan a route out and have a backup route in mind.
  2. Develop a household disaster plan. In case household members are separated from one another during a volcanic eruption (a real possibility during the day when adults are at work and children are at school), have a plan for getting back together. Ask an out-of-town relative or friend to serve as the "household contact," because after a disaster, it's often easier to call long distance. Make sure everyone knows the name, address, and phone number of the contact person.
  3. Assemble a disaster supply kit (see "Emergency Planning and Disaster Supplies" chapter).
  4. Get a pair of goggles and a throw-away breathing mask for each member of the household in case of ashfall.
  5. Do not visit an active volcano site unless officials designate a safe viewing area.

What to do during an eruption

  1. If close to the volcano evacuate immediately away from the volcano to avoid flying debris, hot gases, lateral blast, and lava flow.
  2. Avoid areas downwind from the volcano to avoid volcanic ash.
  3. Be aware of mudflows. The danger from a mudflow increases as you approach a stream channel and decreases as you move away from a stream channel toward higher ground. In some parts of the world (Central and South America, Indonesia, the Philippines), this danger also increases with prolonged heavy rains. Mudflows can move faster than you can walk or run. Look upstream before crossing a bridge, and do not cross if the mudflow is approaching. Avoid river valleys and low-lying areas.
  4. Stay indoors until the ash has settled unless there is danger of the roof collapsing.
  5. During an ash fall, close doors, windows, and all ventilation in the house (chimney vents, furnaces, air conditioners, fans and other vents).
  6. Avoid driving in heavy dust unless absolutely required. If you do drive in dense dust, keep speed down to 35 mph or slower.
  7. Remove heavy ash from flat or low-pitched roofs and rain gutters.
  8. Volcanic ash is actually fine, glassy fragments and particles that can cause severe injury to breathing passages, eyes, and open wounds, and irritation to skin. Follow these precautions to keep yourself safe from ashfall:


    • Wear long-sleeved shirts and long pants.
    • Use goggles and wear eyeglasses instead of contact lenses.
    • Use a dust mask or hold a damp cloth over your face to help breathing.
    • Keep car or truck engines off. Driving can stir up volcanic ash that can clog engines and stall vehicles. Moving parts can be damaged from abrasion, including bearings, brakes, and transmissions.
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What to do after the eruption

  1. Avoid ashfall areas if possible. If you are in an ashfall area cover your mouth and nose with a mask, keep skin covered, and wear goggles to protect the eyes.
  2. Clear roofs of ashfall because it is very heavy and can cause buildings to collapse. Exercise great caution when working on a roof.
  3. Avoid driving through ashfall which is easily stirred up and can clog engines, causing vehicles to stall.
  4. If you have a respiratory ailment, avoid contact with any amount of ash. Stay indoors until local health officials advise it is safe to go outside.

HOW TO SURVIVE A VOLCANO ERUPTION

By Cliff Montgomery - SecretsofSurvival.com

At precisely 8:42 Sunday morning on May 18th, 1980, the greatest natural explosion ever recorded on American soil ripped apart a massive, sleepy peak in Washington state called Mount Saint Helens.

This was a massive volcano eruption.

Shaken 10 minutes earlier by an earthquake measuring 5.1 on the Richter scale, the north face of this tall, symmetrical volcano collapsed, resulting in the largest known landslide in world history. These slabs of earth and ice slammed into nearby Spirit Lake, crossed a ridge 1,300 feet high, and roared 14 miles down the Toutle River.


The avalanche rapidly released pressurized gases that had long been surging inside the mountain. For at least a week its northwestern flank had been bulging out as much as 12 feet a day from the increasing pressure of rising magma.

And then Mount St. Helens - a pristine, previously dormant volcano that had long been a major part of the eastern Washington landscape - mostly ceased to exist.

The explosion was five hundred times more powerful than either of the atom bombs dropped on Hiroshima or Nagasaki.

The tremendous lateral blast turned 250 million cubic yards of mountain into a turbulent, stone-filled wind that swept over ridges, toppled trees and scorched the earth nearby at temperatures well over 600 degrees Fahrenheit, flattening or disintegrating practically everything within a 150 square miles of the volcano’s northern side.

Within minutes the eruption began blasting material straight up into the sky; it would continue for 9 hours. The top 1,317 feet of the peak and most of its northwestern side were no more. In its place would eventually be a gaping, horseshoe-shaped crater 2,460 feet deep, making St. Helens little more than a gargantuan shell.

The final result of this activity was a mushroom-shaped column of volcanic ash that rose thousands of feet skyward and drifted across eastern Washington and beyond, turning day into darkest night as gray ash fell over a major part of the southwest. Melted snow and earth became wet, cement-like slurries of rock and mud scouring all sides of the volcano. Searing flows of white-hot lava oozed from the gaping crater.

Fifty-seven people lost their lives when Mount St. Helens erupted that May morning. But a few like Jim Scymanky actually lived through it, thanks only to a simple combination of sheer endurance and dumb-assed luck.

If you’ve ever considered trying to ‘tough through’ a massive volcanic eruption to see the sights, consider Jim’s story.

Scymanky was working that day as part of a four-man logging team above the Toutle River. Washington Gov. Dixy Lee Ray had ordered all people out of a 10-mile-zone around St. Helens. Scymanky and his crew were issued work permits allowing them to work just outside the perimeter.

The crew figured they were safe.

Until a Hispanic co-worker on the ridge suddenly raced downhill shouting, in Spanish, “The volcano is exploding!”

Scymanky barely tossed his saw when he heard what he says sounded like two jetliners racing toward him. That’s when the forest disappeared.

Rocks-cum-missiles blew the trees apart. Then came the ash. A hot wall of cinder, blown by a force that even 10 miles from the blast whipped winds around Scymanky at around 55 mph, battered most everything to the ground.

There was no light. Scymanky sucked in pure ash for more than a minute. “I can’t see. I can’t breathe. I feel like I’m being buried. The pain is just unbearable,” he recalled recently to MSNBC News.

Scymanky says the heat was so intense that his cotton gloves melted onto his hands. “You didn’t know where the hell you were,” Scymanky says. “One minute you’ve got landmarks all over - you know where the stream is, where the roads are . . . [but after the blast,] no roads. No streams. No nothing. I mean, just gone. It was like it picked you up and put you on a different planet.”

Scymanky saw that all four men somehow survived the blast.

Their luck was about to run out.

Their bodies scorched, the four wandered 4.5 miles before reaching the result of a huge rock avalanche that blocked the only way out of the mess. Meanwhile the river below was rising quickly, filling the valley with mud and volcanic debris.

Two of the men refused to give up. One climbed the avalanche; the other tried going across the river. They were never heard from again.

And Jim? “I thought to myself - and I didn’t say it to anyone else - ‘How long is it going to take to die? This is a long, painful death,’” says Scymanky now.

But shortly before that thought became reality, two National Guard helicopters swooped down to rescue Scymanky and the other co-worker. The other man later died.

Scymanky suffered severe burns on his back, neck, arms and legs. He vomited ash for days. A vast, gray landscape lay where once were acres of forested slopes. The total eruption lasted 9 hours, but Mount St. Helens and the surrounding countryside would be changed for years.

Scymanky never logged again. He now makes a living restoring antique cars.

Most active volcanoes don’t explode like this one or Vesuvius, the volcano that buried and perfectly preserved the ancient Roman city of Pompeii about 2,000 years ago, killing all its inhabitants with rivers of lava and ash.

In most cases, an volcanic eruption simply produces a combination of slow-moving lava and poisonous gases - a wonder very dangerous in its own right. However, some rather benign eruptions can be viewed, provided you always follow a guide’s advice, stay far clear of the lava and upwind of the gases.

But even with the slowest-moving lava flows, danger can occur if you’re not careful. How can you escape it? Understanding and listening to the experts is key.

 

Vulcan’s Workshop: The Workings of a Volcano

Very few natural wonders inspire as much awe and fear as the workings of a volcano.

Stanley Williams, a vulcanologist (volcano expert) who led an ill-fated scientific party into the mouth of an Arizona volcano shortly before its eruption a few years ago, co-wrote with ghost writer Fen Montaigne in the preface to their recent book, ‘Surviving Galeras’:

My fascination with volcanoes, now a quarter century old, taps into something universal and timeless. As they watched fountains of lava spew from Mount Etna in Italy or Popocatépetl in Mexico, the ancients believed they were witnessing a phenomenon linked to the origins of the universe. The flames and magma gushing from a volcano came from a place as mysterious as the heavens above. Small wonder that the Mayas, Aztecs, and Incas tossed virgins into the mouth of this beast; it was capable of destroying villages, towns, entire civilizations in an instant. Human sacrifice, they believed, would placate the monster.

To the Greeks, volcanoes were a direct conduit to Hades. The Romans believed the entrance to hell was in the Phlegraean Fields, next to Vesuvius, where gases poured out of hundreds of fumaroles. Vulcan - the Roman god of fire - lived deep inside a mountain on Vulcano, in the Aeolian Islands. There, at his underground forge, he rocked the earth and unleashed eruptions as he made weapons for Apollo, Hercules, and the other gods. The Icelanders, living on an island that was but a mound of volcanoes, believed Hell’s gateway was the crater of the massive fire mountain Hekla.

One things the ancients understood was that there is a lot of activity going on beneath the earth’s crust.

This little planet may look like a single solid mass, but it’s really made up of several massive plates of earth and rock. These crustal plates are constantly moving and colliding with one another, creating earthquakes and the pressure zones that lead to volcanic eruptions.

Underneath those sliding and colliding plates is hot, melted rock known as magma; it sometimes collects in areas of high pressure called, naturally enough, magma chambers. When this pressure builds up and becomes too great, the magma sometimes explodes upward in a great cataclysmic event. This is a volcano.

When this magma has reached the surface of the earth’s crust, it’s called lava.

Volcanic gases are also emitted during the eruption. The chief gas is water vapor or steam, although it can also contain carbon dioxide, nitrogen, sulphur, carbon monoxide, hydrogen, chlorine, and numerous other gases. The high-pressure gases also eject red-hot fragments that range in size from huge blocks to fine dustlike particles.

There are many types of these fragments, officially called pyroclastics. They include:

Blocks - larger fragments, made of crustal pieces or older lava;

Volcanic bombs - masses of new lava blown from the crater and hardened during flight, becoming spindle-shaped as they fly through the air;

Breadcrust bomb - a type of pyroclastic that resembles a loaf of French bread with large cracks in the crust;

Lapilli - (Italian, meaning “little stones”) Smaller, broken fragments about the size of walnuts;

Pumice - Produced by acidic lavas where there is so much gas content that the magma bubbles as it rises to the surface. Pumice contains many air spaces that were formed by expanding gases, so it will float in water;

Pele’s hair - A material resembling spun glass created by lava fountains (where steam jets blow lava into the air); named after the Hawaiian goddess of volcanoes; very similar to rock wool, a man-made material widely used for insulation, etc.

Lava is composed mostly of silicon dioxide (SiO2). The lava’s silicon dioxide amount can be:

Basic - Lava with less than 52% of SiO2

Intermediate - Lava that contains between 52% and 66%

Acidic - Lava that contains 66% or more of SiO2.

After issuing forth from the crater via cracks, holes, or fissures, lava will spread out like tongues of hot, melted rock. Sometimes sheets of lava can cover thousands of square miles, far away from their source. Liquid lava can flow farther than the thicker, more viscous lava types.

Lava will eventually cool and harden, usually into one of two types. The ‘ pahoe’ type (known as “corded” in Italy) has a smooth, billowy surface, and resembles huge coils of rope; these mainly develop from basic lava. The ‘aa’ type of cooled lava consists of angular, jagged blocks, often with sharp edges and spiny crags.

Sometimes, the outer surface of a lava flow will harden when the inside core is still hot and flowing. If this middle part flows away, it will leave the outer cylinder, creating a lava tube. Lava tubes can continue for several miles. The world’s longest tube is in Northern California, extending 13.8 miles in length. In fact, one such tube near Dubois, Idaho, has been made into a bomb and fall-out shelter that in a pinch can hold the town’s entire population of about 2,500.

Another interesting creation is the tree mold or lava tree, formed when liquid lava encases a tree trunk. The tree will usually burn, leaving details of its bark or wood preserved in the cooled lava.

 

How Do I Survive This Thing?

There is not much an individual can do to prepare for a volcanic eruption, but it is always good to have a good knowledge of this phenomenon. Be aware of the hazards that can come with an eruption: the flying debris, hot gases, lava flows, potential for explosion, mudslides, avalanches, and geothermal areas. Prepare provisions, water, food, blankets, and medical supplies if you live around a volcano before anything happens. Also be ready to get up and outrun flowing lava . . . and yes, we’re quite serious.

Visitors to volcanoes will find themselves experiencing a beautiful outdoor recreation. These tourist sites usually ask people to use common sense when climbing slopes and sightseeing, and we’re not about to argue with them. Take lots of water, don’t overstrain yourself, and use a knowledgable guide whenever you can.

Above all, use caution when visiting active volcanoes. Do not venture toward any activity, and consult local experts on the area. Follow all recommendations, regulations, or requests of officials.

Here are some things to watch out for:

a.) Lava flows - Stay away from lava flows. Not all of them will be red-hot and obvious; some move very slowly and appear as dark and solid, but are liquid beneath the surface. Also, do not try to cross an active flow; you might get trapped by multiple lava streams.

b.) Pyroclastic flows - Do not visit volcanoes that are having or are about to have pyroclastic explosions like Mount St. Helens had in 1980, for (hopefully) obvious reasons. The high temperature around such a volcano can itself be life-threatening.

c.) Colcanic domes - Volcanic domes and plugs in craters may seem harmless, but they can explode without warning. Footing and glassy rocks can also be very dangerous. Some cooled lava of this sort can resemble jagged pieces of glass. Wear good, solid hiking boots on the mountain - never go barefoot. Be sure of your step.

d.) Lahars and floods - Be careful when crossing lahar (debris flows), for they can gush in large and small floods.

e.) Gases - Avoid areas where volcanic gas is released. Carbon dioxide, sulfur dioxide, and hydrogen sulfide can kill quickly and silently. You may not be able to hold your breath long enough. If you see a location around an active volcano with dead vegetation, carcasses, or bones, do not enter it.

f.) Geothermal areas - hot springs, mudpots, and geysers are also very interesting, but don’t go across unexplored areas that contain many of them. Stay on marked trails, because the thin silica crusts over boiling pools can break if stepped upon. Falling in can cause third-degree burns or death.

The bottom line? Appreciate the natural wonder of volcanoes, but be careful, too.

 

Okay, How Do I Really Protect Myself?

Alright, let’s get to the nitty-gritty on surviving a volcano.

Before an Eruption Occurs:

Discover whether there are volcanic hazards in the area likely to affect you.

If you live in an active volcanic zone, always assume that you may have to deal with the effects of an eruption.

If you live in an area that could experience a lava flow during a volcanic eruption, know a quick route to safe ground.

Listen to authorities regarding volcanic activity.

If vulcanologists agree that a life-threatening eruption is likely to take place, a Civil Defense Emergency will be declared and the danger area evacuated. Listen to your radio or TV for information and follow civil defense advice.

During an Eruption:

Save water in your bath, basin, containers or cylinders at an early stage - supplies may become polluted.

Stay indoors with your pets as much as possible.

Wear mask and goggles if you go outside, to keep volcanic ash out of your eyes and lungs.

Keep gutters and roof clear of heavy deposits of ash, which can collapse the roof.

Take your outdoor clothing off before entering a building - volcanic ash is difficult to get rid of.

Take your Getaway Kit with you if you have to leave. Turn electricity and gas off at the mains. If you turn gas off, have a professional check for leaks in case of damage before turning gas on again.

Keep below ridge lines in hilly terrain - the hills will offer some protection from flying volcanic debris.

DON’T Go sightseeing!

DON’T Leave home unless advised to by the Civil Defense.

 

Light At The End

If we seem to be going on about Mount St. Helens now and again, it's only because that eruption was the best-documented in history. Spurred on by geologists, an array of photographers and reporters were there - along with a small army of scientists - to record the events as they happened.

In 1982 the President and Congress created the 110,000-acre National Volcanic Monument for research and education. Inside the monument, the environment has been left to respond naturally to the disturbance.

The volcano continued to erupt until 1986, violently at first, then quietly building a lava dome. Thick lava eruptions oozed out, each one piling on top of the next, like a stack of gigantic pancakes. The lava dome is now 920 feet high. The United States Geological Survey scientists continue to monitor the volcano for earthquakes, swelling, and gas emissions. The old peak has taught us much about a volcano’s inner workings and its aftermath.

One heartening tale of Mount St. Helens has been the surprisingly quick return of plants to the mountain. Peter Frenzen, monument scientist for the Mount St. Helens National Volcanic Monument, says the key was that much of the nearby forest was still blanketed by snow that May day. The protected plants laid the groundwork for the mountain to grow green once again.

Studying the many patterns of regrowth after a volcanic eruption like St. Helens can help people in other parts of the world understand how life grows back after an earthquake, hurricane or flood.

But for all the advances in forestry and ecology, the strongest scientific legacy of Mount St. Helens is probably in vulcanology. Monitoring the mountain for months before it blew allowed scientists to track the evolution of an eruption from a very early stage.

The cataclysm altered their perceptions. Nobody had ever seen a volcano fall apart before, but that’s what St. Helens did when its north face collapsed just before the blast, unleashing a torrent of debris.

A practical application of the new understanding of volcanoes is the Volcano Disaster Assistance Program. When a volcano is about to erupt in a developing country, scientists specially trained at the St. Helens site are sent to assist with evacuation and recovery efforts.

The program’s most famous success was with Mount Pinatubo in the Philippines, where the team helped evacuate more than 75,000 people and saved millions of dollars in damages by moving portable equipment out of harm’s way in the 10 weeks between the mountain’s reawakening and its climactic eruption.

 

Rainier ‘The Big One’?

What remains of Mount St. Helens is a cross-section of a volcanic crater that reveals thousands of years of eruptive history for study. Huge faces of white crumbly clay surround the crater floor. Volcanologists have since found large deposits of the exact same clay on Mount Rainier, less than 100 miles to the north.

That helps vulcanologists evaluate the potential damage of a Rainier eruption, which would be colossal. Rainier is 4,000 feet taller than St. Helens was, much closer to a large population center - Seattle - and covered with millions of tons of ice that would unleash huge mudflows down the rivers leading to Puget Sound, endangering more than 250,000 people.

Any evacuation would be a major undertaking, but Mount St. Helens has motivated scientists and local governments to develop a detailed emergency management plan.

 

“This Is It!”

The wonderful, horrible loneliness vulcanologists experience can perhaps be summed up by looking at David Johnston of the U.S. Geological Survey. In 1980 Johnston was a 30-year-old scientist sent to study the impending eruption of Mount St. Helens.

On May 17, 1980, Johnston landed a helicopter on the bulging northwest side of the volcano to take gas samples. Another young vulcanologist, Harry Glicken, took two pictures of Johnston with the help of a telephoto lens as he worked. They show a mere speck of a man, dressed in blue jeans, bending over in the midst of taking a sample from the back of the beast.

Everyone knew some big eruption was imminent. No one went up with Johnston that day.

Camping at an observation post on a ridge just 5.7 miles northwest of the summit, Johnston barely had enough time the next morning to radio his colleagues in the nearby town of Vancouver when it came.

He screamed his last words into a radio at 8:42 a.m. as the superheated ash cloud, as destructive as the greatest nuclear blast, ripped toward him at about 300 mph.

“Vancouver, Vancouver,” he cried excitedly, “this is it!”

That spot is now known as Johnston Ridge.


ANOTHER INTERESTING ARTICLE:

How to Protect Yourself from a Volcanic Ash Fall and Its Health Hazards
 

 

 
 
 
 
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Mariejo Mariss S. Ramos 2010-68560

BA Journalism

University of The Philippines Diliman
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