MOUNT ST. HELENS: A GIANT WAKES UP
YV Introduction
Focus
This News in Review story focuses
on the unfolding
drama of Mount St.
Helens, a giant
volcano on the
West Coast of
North America, and
how volcanologists
try to predict
volcanic eruptions.
Did you know . . .
The Klickitat people of the West
Coast know Mount
St. Helens as
Louwala-Clough, or
“smoking mountain”?
Further Research
To see a fabulous
satellite image of
Mount St. Helens,
go to
vulcan.wr.usgs.gov/
Volcanoes/MSH/
summary_mount_
st_helens.html.
Scroll down to the
bottom of the page
and click on “Annotated NASA Image.”
The Klickitat people once lived in the
Cascade Mountains. They tell a legend
that explains the creation of Mount St.
Helens.
into Mt. Hood and Klickitat into Mt.
Adams. Lewit became the beautiful
Mount St. Helens. And that is how the
mountains came to be.
Bridge of the Gods
People who live near volcanoes tend
to hold them in high regard. Only
volcanoes, and the earthquakes that
often go with them, have the power to
shake the ground beneath our feet, wipe
away a forest in an instant, or bury a
city in ash. Volcanoes have blown up
islands and created new ones. And none
of us can control them.
And the spectacle? It is truly a sight
of a lifetime to see a volcano’s brilliant
orange lava lighting up the night sky or
to see plumes of steam and ash shooting
kilometres into the sky. That is exactly
what tourists saw at Mount St. Helens
in the state of Washington in October
2004. By historical standards, this display
was nothing. But it was a reminder of the
nightmare this very volcano had unleashed just 24 years earlier.
In 1980, Mount St. Helens had exploded with a ferocity no one had
expected. More than 600 square
kilometres of stately forest had been
destroyed in an instant, wiped clean of
life—a not-so-subtle reminder that we
will always be at the mercy of the
powers of nature.
A long time ago, an old woman
named Lewit gave the gift of fire to
the Klickitat and Multnomah people,
who lived in the Cascade Mountains.
She brought the fire to Wy’East, the
chief of the Multnomahs, and
Klickitat, chief of the Klickitats. In
return, the Great Spirit turned Lewit
into a young woman.
As the sun rose on the Columbia River,
Lewit stood on the Bridge of the
Gods. The people gratefully accepted
the fire she brought. They would use
it to heat their lodges, cook their
food, and bring light to the night.
Everyone was happy, including
Wy’East and Klickitat, both of whom
fell in love with Lewit. They each
brought her gifts. Lewit could not
decide. They brought her bigger and
better gifts. On and on it went.
Finally fighting broke out, and they
threw rocks and stones at one another. The Great Spirit became angry
at such foolish behaviour, so it shook
the Earth till the Bridge of the Gods
fell into the river. It changed Wy’East
To Consider
1. Reread the Klickitat legend. Identify any references to volcanoes, earthquakes, or the relationship of humans to these forces of nature.
2. What does the Klickitat legend teach about human behaviour? About the
forces of nature?
3. In your opinion, why do people visit active volcanoes? Would you like to
visit one? Explain.
4. Brainstorm possible benefits of predicting the timing and strength of
volcanic eruptions accurately.
CBC News in Review • December 2004 • Page 31
MOUNT ST. HELENS: A GIANT WAKES UP
YV Video Review
Complete the
questions in Part I
of this exercise
while reviewing the
video.
Part I
1. How many thousands of years ago did Mount St. Helens first become
active? _____________
2. When did the volcano erupt again after more than a hundred years of
dormancy? _____________
3. How many people died as a result? _____________
4. How long was the volcano dormant again after 1986? __________________
5. What did scientists hear that made them issue a warning to evacuate the area?
6. Describe what scientists think is happening underneath the volcano.
7. What could happen when the plug of hardened lava gives way?
8. What do scientists now use to measure movements of rock or ice?
9. What is the name of the waveform that Bernard Chouet discovered while
studying Mount St. Helens? How are these sound waves produced?
10. Chouet identified long-period events at the Galaras, a volcano in Colombia. What disaster occurred in 1991 because a volcanologist ignored
Chouet’s warnings.
11. Explain Chouet’s theory about what happened inside the volcano by
filling in the blanks:
• Hot _____________________ came close to the groundwater underneath
the volcano.
• The water was heated and turned to _______________________.
• This caused ______________________ to be built up under the volcano,
which the volcanologists could read as long-period events.
12. Why are long-period events more reliable than other seismic activity in
predicting eruptions?
CBC News in Review • December 2004 • Page 32
Part II: Volcano Word Search Puzzle
Find these words in the volcano word search puzzle below. Words go up, down,
sideways, and on the diagonal. They appear both forward and backward. (If
you have time, try to find the meanings of terms you do not recognize.)
andesite
ash
basaltic lava
caldera
composite volcano
convergent margin
crater
divergent margin
dormant
earthquake
eruption
fault
geothermal energy
geyser
hot gas
hotspot
lahar
lava
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CBC News in Review • December 2004 • Page 33
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MB
MOUNT ST. HELENS: A GIANT WAKES UP
YV Mount St. Helens
Did you know . . .
Mount St. Helens
received its current
name from Captain
George Vancouver
in 1792? He named
it after a British
ambassador to
Spain.
“Vancouver! Vancouver! This is it!” —
the last words ever spoken by volcano
expert David Johnston, as he sent a
warning from the Coldwater II observation post, about eight kilometres away
from Mount St. Helens, at 8:32 a.m. on
May 18, 1980
Some volcanologists spend their
whole lives studying a volcano without
ever seeing it erupt. Even very active
volcanoes like Mount St. Helens might
erupt only once every few thousand
years. Thirty-year-old David Johnston
got the sight of a lifetime, however,
when the volcano he was studying
exploded dramatically. But he paid a
heavy price. After speaking the words
above, the blast of the eruption blew
him away, burying him and the surrounding wilderness in six cubic
kilometres of ash, mud, and volcanic
debris.
An Ancient Beauty
Before the eruption in 1980, Mount St.
Helens had been a beautiful sight. Its
tall, symmetrical cone was the shape of
a perfect composite volcano, or stratovolcano. The mountain drew many
admirers to southwestern Washington.
(Washington State lies directly south of
British Columbia.)
Although Mount St. Helens had been
erupting for nearly 40 000 years, its
cone only started forming about 2 200
years ago, making it rather young for a
volcano. But young does not mean
inactive. Mount St. Helens is by far the
most active of the Cascade Mountains,
having had about nine periods of activity during the last 10 000 years.
Despite its active nature, the volcano
hadn’t erupted since 1857, so few
people thought it posed any immediate
danger. The area became beloved for its
wild beauty, and people travelled there
to swim, camp, hike, hunt, canoe, and
just enjoy the outdoors. Fortunately the
area had remained relatively uninhabited.
The Awakening
For two months before May 1980, the
volcano experienced more than 10 000
minor earthquakes and hundreds of
small underground explosions. What’s
more, the north flank was expanding—
bulging out—more and more every day,
until it had increased in size by more
than 80 metres. Volcanologists were
worried. On their recommendation,
authorities created a “red” danger zone
and tried to keep people away.
The morning of May 18 was bright
and clear. Then an earthquake that hit
5.1 on the Richter scale, (a scale that
measures the strength of an earthquake)
started an unstoppable domino effect.
The earthquake shook loose the bulging
north face of the mountain, causing the
largest landslide in recorded history. In
the massive rock-debris avalanche, the
whole side of the mountain slid away,
essentially taking the cap off the pop
bottle.
The resulting blast shot out hot gas,
ash, and rock debris, travelling at 1 100
kilometres per hour with the power of
about 27 000 Hiroshima-size atomic
bombs. Temperatures reached 300
degrees Celsius. Because the north side
of the volcano had disappeared, the
volcano erupted laterally, or sideways.
This factor increased the degree of
damage to the surrounding area. Within
seconds, the blast wiped out everything
CBC News in Review • December 2004 • Page 34
Did you know . . .
The entrepreneurial spirit endures, even in the
face of disaster?
After the eruption
of Mount St. Helens, a local business
collected the ash,
moulded it, baked
it, and sold the
results as “Genuine
Mt. St. Helens Ash
Trays”!
in its path. The direction of the blast
was the most surprising aspect of the
eruption, for which no one was prepared.
The snow cap melted instantly,
creating a super-hot torrent of water,
ash, and rock debris—a lahar—that
swept down the river valleys, wiping
out all bridges, forest, and wildlife in its
path.
A mushroom-shaped column of ash
rose 19 kilometres above the volcano,
and spread quickly. It turned day into
night, as grey ash filled the sky and fell
over eastern Washington State and
beyond. The wind carried 490 tonnes of
ash that settled across 57 000 square
kilometres.
The eruption lasted nine hours, but it
did the most damage during the first
few moments. It wiped out 600 square
kilometres of forest. It killed 57 people
and destroyed the property of many
more. It killed 5 000 deer, 1 500 elk,
200 black bears, one million birds, and
11 million salmon and steelhead trout.
The Recovery
Environmental advocates had been
lobbying for a wilderness park in the
Cascades for decades. After the volcano
erupted, they got one in the form of the
Mount St. Helens National Volcanic
Monument. Authorities decided to leave
the devastated area alone to regenerate
without human interference. They
didn’t replant trees or reintroduce
animals. Scientists rejoiced, as they
would have a rare chance to observe
nature at work.
To the scientists’ great surprise,
greenery appeared right away. Roots
had been left undamaged under the
earth. Dead insects blew in—the first
creature found alive on the devastated
land was a carnivorous carabid beetle,
which eats dead bugs. The land now has
a green blanket. Despite these signs of
renewal, however, it will probably be
two centuries before the richness of the
wilderness returns to pre-1980 levels.
Tourism
People love a disaster. So every year,
more than half a million people come to
see the site of the Mount St. Helens
eruption. The U. S. Parks Service built
a glass-walled visitors’ centre on a
ridge overlooking the volcano. It features interactive videos, touch-activated
terminals that explain various aspects of
the explosion and renewal, and a movie
about the eruption. A gift shop sells
lava ash by the bottle, and a snack bar
sells “Lava Burgers,” which come with
a dome of cheddar cheese and hot green
peppers.
Waking Once Again?
Mount St. Helens kept erupting very
quietly for a few years. During that time
it built up a lava dome nearly 300
metres high and about a kilometre
across. The lava dome grew by oozing
out lava, which spread out slowly,
creating what looks like a pile of sloppy
pancakes. Then, in 1986, the volcano
went quiet.
Not until October 2004 did it show
any signs of re-emerging from its great
sleep. Seismologists began noticing
earth tremors—lots of them. New steam
vents appeared, and the lava dome
began to swell.
By the end of the month, volcanologists were worried. None of them
expected an eruption of the magnitude
of the 1980 blast. The earlier eruption
had blown off the top of the mountain,
so the pressure of gas and magma could
never build up to the degree that it had
before. Nonetheless, scientists issued a
“Notice of Volcanic Unrest,” and
officials scaled back access to the area
CBC News in Review • December 2004 • Page 35
Further Research
To see what Mount
St. Helens is doing
right this minute,
check out the
VolcanoCam set up
at the Johnston
Ridge Observatory:
www.fs.fed.us/
gpnf/volcanocams/
msh/index.shtml. It
updates every five
minutes.
surrounding the volcano. They feared
that the volcano might spew rocks or
that one of the many earthquakes would
trigger a landslide. In November, lava
began pouring slowly out of the lava
dome.
Scientists began recording earthquakes of magnitude 2.5 on the Richter
scale. They happened about four times a
minute. The warning level was raised to
“Volcano Advisory.” Then, as if on cue,
the volcano spouted out a fivekilometre column of steam and ash on
November 1. It did no damage, however, and lasted a mere 24 minutes. The
scientists were satisfied—it had happened as they had predicted: like a
hiccup.
A few days later, though, they were
taking it all back. Not only were they
getting indications that new magma was
moving up under the volcano, but they
also detected hydrogen sulphide, indicative of moving magma. Even worse,
they detected two harmonic tremors.
About 2 500 visitors and journalists
were told to evacuate.
Monitoring a volcano can be a nervewracking game. First it’s on; then it’s
off. Then it’s on again.
Activities
1. Create a numbered list giving a step-by-step description of the 1980 eruption of Mount St. Helens.
2. List six facts or figures about the eruption. Which do you find most impressive? Why?
3. What surprised environmental scientists in the years following the 1980
eruption?
4. Why are scientists convinced that any subsequent eruptions on Mount St.
Helens will not be as powerful as the 1980 eruption?
Extension Activities
1. Do some research to find out the current status of Mount St. Helens. To
find an up-to-the-day status report on Mount St. Helens, visit the USDA
Forest Service site: www.fs.fed.us/gpnf/mshnvm.
2. Research scientists often feel passionate about their work, as was the case
with David Johnston, who continued to work fairly close to Mount St.
Helens despite knowing that it could blow at any time. Find out the difference between a seismologist and a volcanologist. Create an organizer to
compare what each one does. Explain what you would like best and least
about these jobs.
CBC News in Review • December 2004 • Page 36
YV MOUNT ST. HELENS: A GIANT WAKES UP
YV Why Volcanoes Blow Their Tops
Did you know . . .
• Volcanoes in
eruption are those
actively releasing
material?
•␣ Active volcanoes
are those that have
erupted in the past
200 years?
•␣ Dormant volcanoes are inactive
volcanoes that are
expected to erupt
some time in the
future?
•␣ Extinct volcanoes
are never expected
to erupt again?
Volcanoes happen because high temperatures melt rock, creating magma.
This molten rock makes its way up
through Earth’s crust. But why? Melted
rock, especially when mixed with hot
gases such as sulphur dioxide, is lighter
than the solid rock of the mantle (the
region between the crust and core of
Earth), so it rises. The magma and hot
gases collect in pools or cracks just
under the surface. When pressure from
below increases, the magma and pentup gases burst out of their confines into
the air above.
Volcanoes occur in two places: where
Earth’s plates meet and at hot spots.
Hot spots are areas of the mantle that
are particularly hot, and that superheat
the rock in the plate above it. The
islands of Hawaii were created—and
continue to be—by volcanoes bursting
over a hot spot. The currently erupting
Kilauea, on Hawaii’s Big Island, is a
shield volcano. For the most part, the
lava flows out slowly and gently,
resulting in smooth, hill-like volcanoes.
Most volcanoes, however, occur not
at hot spots but at plate boundaries.
Earth’s crust is composed of a number
of plates that float on top of the mantle.
Divergent boundaries occur where the
plates are moving apart. For example,
the Atlantic rift, which runs down the
middle of the Atlantic Ocean, is a
divergent boundary. As the plates move
apart, magma flows up and out of the
resulting gaps. Because they are not the
result of a massive build-up of pressure,
the explosions are fairly calm, and
gently sloping shield volcanoes result.
Convergent boundaries occur where
the plates are moving together. Sometimes the lighter, thinner oceanic plates
slide underneath the heavier, thicker
continental plates. This creates a subduction zone. As the plate that is
pushed down into the mantle heats up,
it melts and then rises through the crust
to create a volcano. Convergent boundaries occur all around the Pacific Ocean
in the famous Ring of Fire. Here the
violent eruptions create cone-shaped
volcanoes called stratovolcanoes, which
are made of alternating layers of lava
flows, ash, and other volcanic debris.
Mount St. Helens is a stratovolcano.
Finally, transform-fault boundaries
occur where two plates slide against
each other. The sliding is usually quite
jerky, and can create many earthquakes
as well as volcanoes. The San Andreas
Fault in California, for example, regularly causes earthquakes.
Underneath the surface of Earth,
molten rock is called magma. If it
reaches the surface, we call it lava.
Rocks have different composition, so
they create different types of lava.
Basalt lava is very fluid—it flows
quickly. Because it’s so runny, it’s harder
for pressure to build up, and eruptions are
less explosive. Basalt lava typically
creates shield volcanoes. Andesite lava
is stickier—it’s thick and flows slowly
because it contains more silica. Eruptions with andesite lava are more explosive and harder to predict. Andesite lava
usually creates stratovolcanoes.
To Consider
1. Where do volcanoes occur? In your explanation, use the terms hot spots,
plate boundaries, divergent boundaries, convergent boundaries, subduction zones, and transform-fault boundaries.
2. Compare and contrast stratovolcanoes and shield volcanoes.
CBC News in Review • December 2004 • Page 37
MOUNT ST. HELENS: A GIANT WAKES UP
YV Volcanic Blasts from the Past
Did you know . . .
A tsunami formed
by Krakatoa picked
up the Dutch ship
Berouw and
dropped it three
kilometres inland
and nine metres
above sea level?
After learning about the enormity of the
Mount St. Helens eruption in 1980, you
might think that little that nature could
offer would beat it. Think again.
Krakatoa
There was once an island in the Sunda
Strait of Indonesia called Rakata. A
volcano on that island, called Krakatoa
(also called Krakatua), had developed at
a point where the Indian-Australian
plate was sliding under the Eurasian
Plate. On August 26, 1883, the volcano
blew two-thirds of Rakata Island clean
away with the power of 100 000 hydrogen bombs—the most violent eruption
of modern times. It was a staggering 60
times more powerful than the explosion
of Mount St. Helens.
The sound of the blast alone was
remarkable. The cataclysmic boom was
heard over a third of the Earth’s surface. It could be heard 5 000 kilometres
away. Even today that boom is recognized as the loudest sound ever heard
on Earth. The volcanic ash that poured
out of the volcano darkened the skies
for days, and lowered global temperatures for several years.
But the worst was yet to come. After
the explosion, the volcanic chambers
that had been filled with magma collapsed, creating tsunami waves of such
immensity that they travelled halfway
around the world. But first they did
their damage in the Sunda Strait. Waves
reaching a height of nearly 40 metres
smashed into the islands of Java and
Sumatra. People and animals alike were
crushed, drowned, or swept out to sea.
The tsunamis killed more than 37 000
people.
Eruptions of this size occur only once
every few hundred years.
Vesuvius
Can they get any more powerful? Yes.
In the year 79, the Roman city of
Pompeii was taken by surprise when
Mount Vesuvius, about eight kilometres
away, exploded. Scientists say the
explosion was greater than that of
Krakatoa. Although no lava reached
Pompeii, a rushing cloud of suffocating
poison gas and ash did. People were
stopped in their tracks. They had time
to clutch their children if they were
near, and then they died. Over the
centuries, the ash that covered these
people in their last moments turned to
rock, even as their bodies disintegrated.
When archaeologists found the ash-rock
remains, they made plaster casts, and
revealed to us a moment in time.
Santorini
Have you heard the worst? Perhaps not.
Around 1650 BCE, the Aegean Sea (in
the Mediterranean) experienced an
explosion that was at least six times
more powerful than the one at
Krakatoa. Some scientists speculate that
tsunamis and ash resulting from the
explosion of the Santorini Island volcano may have destroyed the legendary
city of Atlantis.
Etna
Etna, near Catania, Italy, is Europe’s
largest and tallest active volcano. It has
been in a state of near continuous
eruption for almost a million years. The
early Romans called it the home of
Vulcan, blacksmith to the gods. When
Vulcan practised his craft, the mountain
roared.
Etna is a very tall, very complex
basaltic stratovolcano located where the
CBC News in Review • December 2004 • Page 38
European and African geological plates
collide. It has four summit craters and
250 cinder cones. It takes up a staggering 1 200 square kilometres. It is famous for the sheer volume of its lava
flows.
What’s even more remarkable about
Etna is the way that people have learned
to live near it. Etna overlooks Catania, a
city of 315 000 people. The people call
it a “good volcano” because its eruptions tend to be mild, the lava flows
slowly, and it has killed only 100
people in the space of 2 000 years.
People seem to forget that in 1669 it
destroyed Catania.
In 2002–2003, the eruptions became
more violent than usual. Lava engulfed
an important skiing and tourism centre
on the mountain, the Piano Provenzana.
The Catanians watch and wait, hoping
their “good volcano” calms down once
again.
Yellowstone National Park
Yellowstone Park in the United States
is well known for its many geysers and
hot springs. These provide evidence of
the massive lake of magma about 80
kilometres long and 50 kilometres wide.
It has caused 142 massive blasts over
the past 17 million years. Many of these
were about 1 000 times more powerful
than the 1980 Mount St. Helens eruption. When will it explode next? The
good news is that it explodes only about
once every 600 000 years. The bad
news? It’s been more than 600 000
years since the last explosion!
Inquiry
1. Often it’s not the initial blast or lava flow that kills people. Give an example of a deadly side effect of a volcanic eruption.
2. Now that you have read about some of the major volcanic eruptions of
recent history, do you still think that Mount St. Helens’ eruption can be
called a “disaster”? Why or why not?
Extension Activity
Further investigate one of the volcanoes discussed above, one of the following
historic volcanoes, or a volcano of your own choosing. Write a one-page report
about your chosen volcano, including what type of volcano it is, when it has
erupted, and what damage it has done. Include a paragraph to explain what
makes your volcano interesting.
Mount Kilauea, Hawaii
Soufrière Hills Volcano, Montserrat
Mount Pinatubo, Philippines
Nevado del Ruiz Volcano, Colombia
Other
CBC News in Review • December 2004 • Page 39
MOUNT ST. HELENS: A GIANT WAKES UP
YV Predicting Eruptions
Since the late 1700s, more than 250 000
people have died as a result of volcanic
activity. The danger rises as the world’s
population rises. More and more of us
are living under the shadow of a volcano. For example,
• Three million people live near Mount
Rainier in the Seattle area in Washington State.
• Mount Popocatépetl, south of Mexico
City, threatens at least one million
people.
• Near Naples, Italy, a million people
live close to Mount Vesuvius.
If scientists cannot stop volcanic
eruptions from happening, they can at
least warn us when they are going to
happen so we can get out of the way.
Scientists did just that when they
recognized that Mount Pinatubo in the
Phillipines was about to blow its top in
the spring of 1991. First, local Aeta
people felt tremors and warned authorities. Then the Volcano Disaster Assistance Program (VDAP) team flew in to
join Philippine volcanologists to examine the patient. They frantically took its
temperature, listened to its pulse, and
measured its protrusions. Before long,
the experts decided that an eruption was
definitely coming. The nearby towns
were evacuated. When Pinatubo finally
erupted, the explosion was 10 times as
big as the one at Mount St. Helens.
Three hundred people were killed.
While this sounds like a lot of people,
without the evacuation order the casualty figure would have been closer to
50 000.
How They Do It
Volcanoes make distinct creaks and
groans before an eruption. Volcanolo-
gists listen to volcanoes, tracking any
changes that might indicate an increase
in pressure or a change in chemical
makeup. To track these indicators they
use:
• battery- and solar-powered seismographs
• photographic and video cameras
• GPS systems
• satellites equipped with radar that can
measure minute changes in elevation,
for example, where a volcano wall
might be expanding
• satellites that can detect the thermal
infra-red part of the spectrum, and can
therefore detect sudden rises in temperature within a volcano
• systems that analyze the chemical
composition of expelled gases
• computer analyses of long-period
events
• flow monitors that can detect lahars
(massive flows of rock, ash, and
water) from great distances, and
therefore enable quicker evacuation
Co-ordinating Efforts
The Volcano Disaster Assistance Program (VDAP) is a small team of experts
who leave on a few hours’ notice to
travel to any place in the world threatened with imminent volcanic eruption.
They install monitors and measuring
devices so they can get readings by
radio. They gather information primarily on three factors: 1) earthquakes, 2)
deformation, and 3) gas emissions.
Computers put together the information.
If all three factors are increasing, the
team knows that magma is moving
upward toward the surface.
CBC News in Review • December 2004 • Page 40
Quote
“They produce a
tone. So, in a sense,
what the volcano is
doing is singing. It’s
singing its tune to
you. Volcanoes
were really talking
to us, and they
were using a
language that
needed to be
deciphered. —
Bernard Chouet,
CBC News in Review, December
2004
A Promising New Means of
Prediction
The latest and most promising development in the science of predicting volcanic eruptions have resulted from the
hard work of Swiss geophyicist Bernard
Chouet. After Mount St. Helens’ first
eruption in 1980, Chouet began studying the resonance given off by volcanoes. This is a vibration, or low-frequency tone, given off by magma or gas
when under pressure. Chouet recognized that changes in the frequency of
these long-period events signalled
impending eruption.
Chouet uses both ground instruments
and space satellites to gather data. He
usually puts more than 40 sensors on a
volcano, and then ties them all in to a
satellite. The ground sensors listen for
rumbles, which Chouet uses to identify
the materials beneath the volcano. The
satellite helps determine where the
rumbles come from within the volcano.
In this way, Chouet can create a threedimensional virtual map of the
volcano’s interior.
A year after Colombia’s Nevado del
Ruiz volcano erupted in 1985, killing
23 000, Chouet studied the seismic
record just before the eruption. It was
filled with long-period events. He
continued his work in earnest, and in
1991 successfully predicted the eruption of Mount Redoubt in Alaska. In
1993, he predicted the imminent explosion of the Galeras Volcano, also in
Colombia but no one listened. Six
scientists and three tourists were killed.
After that, people started listening, both
to Chouet and to the volcano. In December 2000, Mexican scientists using
Chouet’s methods successfully predicted that Popocatépetl volcano would
erupt within two days, and it did. No
one was hurt.
Inquiry
1. Why is it important to predict volcanic eruptions before they occur?
2. What is the VDAP, and how did it avert disaster in the Philippines?
3. Describe Bernard Chouet’s revolutionary new system for predicting volcanic eruptions.
4. Volcanologists find it difficult to get funding to pay for the equipment
and labour involved in monitoring the world’s active volcanoes. Write a
letter to the editor of your local paper to express your opinion on this
issue. Use facts to support your opinion.
Extension Activities
Canada has 200 volcanoes. Some are shield volcanoes, while others are of the
composite variety. Check out the Natural Resources site at www.nrcan.gc.ca/gsc/
pacific/vancouver/volcanoes/volcanoes_e.html.
1. In what province are almost all of Canada’s volcanoes?
2. How many of Canada’s volcanoes have been active in the past 300 years?
3. Can we rely on our volcanoes to stay asleep (remain dormant)? Why or
why not?
4. How should Canada prepare for a volcanic eruption? Consider scientific
research, public education, emergency planning, etc.
CBC News in Review • December 2004 • Page 41
MOUNT ST. HELENS: A GIANT WAKES UP
YV A Reel Activity
Definition
Geothermal comes
from geo, meaning
“Earth,” and
thermal, meaning
“heat.”
Further Research
Ever dive into a
giant open-air
bathtub? If not,
research The Blue
Lagoon, near
Keflavik. You’ll
discover a tourist
experience like no
other! Find out
what its connection
is to Iceland’s
geothermal energy
industry by going to
www.geographia.com/
iceland/
bluelagoon.htm
What would you do if a volcanic eruption threatened your community?
Sometimes it’s hard to imagine how we
would cope. In this activity, you will
get a chance to write a disaster-movie
script, and you can be the star. Will you
cower under the bed or save the
neighbourhood? You decide.
But first, you’ll need a little background information.
Iceland—Living with Volcanoes
Iceland lies right on the Atlantic Rift,
which is the boundary between the Euro
and American continental plates. Iceland exists solely because of its location—it was formed from volcanic
activity. The Atlantic Rift is a point at
which two continental plates are separating. Iceland straddles the rift. As the
tectonic forces pull Iceland apart,
magma flows up to fill the gap. Over
time, Iceland will become bigger and
bigger.
Although just a bit larger than New
Brunswick, Iceland has more than 200
volcanoes and hundreds of hot springs
and geysers. Over the past 500 years, a
third of the world’s lava has flowed out
onto Iceland. In 1783 alone, the Laki
Volcano spewed out the largest known
flow of lava. It killed one in four Icelanders, most of whom suffocated from
clouds of sulphuric acid and fluorine.
Iceland’s Geothermal Power
So how do Icelanders manage to live in
such a volcanic place? Primarily, they
try to stay away from the most dangerous volcanoes, and they have learned to
harness the heat energy lying just below
the surface of their volcanic island
home. Just a few kilometres under
Iceland, temperatures are as high as 250
degrees Celsius. Icelanders have
learned how to harness this very effective alternative energy source.
Water is poured down to a reservoir
in the rocks below the surface, where it
grows extremely hot. The hot water is
then pumped back up to the surface,
where it turns to steam. The steam is
captured and either converted to electrical energy or used directly to heat
buildings. About 85 per cent of all
Icelandic homes are heated in this way.
Activity
Imagine that you’re living in Iceland on a student exchange. You hear that a
research team is drilling into the high-temperature zone deep beneath Iceland’s
surface. They want to drill deeper than they ever have before. You have mixed
feelings about the drilling: you like the benefits for Icelanders and the environment, but you fear that the drilling isn’t safe. Then you switch on the news and
hear of an impending disaster. Something went wrong with the drilling, and a
volcanic eruption is imminent! Where will you go? What will you bring? Who
will you save?
Write yourself into a disaster movie script based on the scenario outlined above.
CBC News in Review • December 2004 • Page 42