Inter III-PVC
READING 4
Volcanoes
Are you familiar with the following names: Anahim, Chilcotin, Garibaldi, Stikine, Wells Gray Clearwater, Wrangell or Cascades? No? Well, if you’re interested in learning more about
Canadian volcanoes, type up any of these names in your search engine and you can begin to
discover something very interesting about Canada’s diverse landscape.
An erupting volcano is undoubtedly, one of nature’s most awesome1 spectacles. Just imagine
how terrified you might be in front of fountains of lava spewing2 into the air? Imagine the terror
of the sound of gases, hissing4 loudly as the bottom of the Earth’s centuries-old furnace3 as
pressure is finally released. In a series of massive explosions, ashes5, cinder6 and rock are blasted
up7 into the atmosphere. What if you were stuck on one of Earth’s paradise islands, as what was
once considered as a dormant8 snow-capped9 mountain, suddenly roared to life10 and you had no
way to escape its wrath11?
Pompeii
You have probably heard or read about Pompeii. In the year 79 A.D., Mount Vesuvius (near
Naples, in what is today called Italy) blew its stack12, launching tons of molten ash13 and
sulphuric gases miles up into Earth’s atmosphere. Poisonous vapours and molten debris
engulfed14 the surrounding areas and literally suffocated neighbouring Roman cities’ inhabitants.
Pompeii and Herculaneum were both obliterated15 over a period of approximately 48 hours.
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Eighteen-year old Pliny the Younger was living with his uncle (Pliny the Elder) in the town of
Misenum when Mount Vesuvius exploded. A few years after the events, which killed his uncle
and almost destroyed all of his family, Pliny the Younger wrote to his friend Cornelius Tacitus.
His letters are the oldest, well-documented testimony16 we have today of a volcano’s eruption.
Let’s read some of Pliny the Younger’s eyewitness report:
“On August 24th... a cloud from Mount Vesuvius, was ascending17 the appearance of which I
cannot give you a more exact description of than by likening it to18 that of a pine tree, for it shot
up to a great height in the form of a very tall trunk, which spread itself out at the top into some
sort of branches; occasioned19, I imagine, either by a sudden gust of air20 that impelled21 it, the
force of which decreased as it advanced upwards, or the cloud itself being pressed back again by
its own weight, expanded in the manner I have mentioned; it appeared sometimes bright and
sometimes dark and spotted, according as it was either more or less impregnated with earth and
cinders.”
Pompeii was buried22 under over 60 feet of pumice23 and ash. It was lost for a very long time
(almost 1700 years). Both Herculaneum and Pompeii were rediscovered in 1599 by architect
Domenico Fontana. However, both towns needed another 150 years before someone started to
unearth24 them. Pompeii and Herculaneum have been unearthed and you can visit a number of
intact buildings. If you ever travel to Italy, try adding Pompeii into your itinerary.
Canadian Volcanoes
You may think that volcanoes are not a part of Canada’s history. If so, you are mistaken25. In
fact, in 1775 a devastating eruption occurred in British Columbia. Aiyansh-Tseax River’s
volcano explosion is said to have killed approximately 2000 natives26. It destroyed two villages,
a number of hunting and berry picking areas, as well as a good number of salmon spawning
streams27. The effects of the volcano’s explosion would certainly be counted in terms of millions
of dollars in today’s currency28.
There are still many active volcanoes along the Canadian Cordillera in British Columbia and in
the Yukon. Although most of Canada’s volcanoes could be described as “Sleeping Beauties”,
they do contribute to Canada’s varied landscape. In fact Canada’s fifth highest waterfall owes its
birth to the many layers of volcanic rock in the Murtle River valley.
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What Causes Volcanoes to Erupt?
When you’re standing on solid ground, it may be difficult to imagine what you might find if you
were to dig deep. Far below the earth's crust29, hard rocks are replaced by soft rocks and then
ultimately by liquid rocks with gases and minerals (often called magma30).
Since the magma is always building up pressure and the earth is always spinning, it sometimes
causes a crack in the earth. The two sides of the crack may shift31. This is called plate tectonics,
known to be the cause of volcanic eruptions. The magma will burst32 through the crack. When
magma comes out or erupts, it is called lava.
Although most people know that lava flows are lethal33 (and they certainly can be destructive),
they are not usually the most deadly kind of volcanic hazard. You could, in fact, watch the
majesty of a volcanic eruption from a safe distance.
Volcanoes and Benefits
Even if volcanoes have caused the deaths of over 200,000 people since the 1400’s, they might
not be our worst enemy. Volcanic ash can greatly improve soil fertility. In many countries, dried
lava is used in building roads. Lava can be a source of precious metals such as gold, silver,
copper and lead. It can even produce precious gems (see opals). Furthermore, when a volcano
erupts, it releases healthy gases like carbon dioxide and hydrogen. When oxygen mixes with
hydrogen, it creates water vapour and that begins the water cycle. A recent BBC special series
called “Earth” credited volcanoes for life on our planet.
On a personal note, Jimmy O. of Manitoba credits volcanoes for his happiness. “When I met
Jenny, it was love at first sight... for me. I was a 98 pound weakling at the time. When I
approached Jenny and declared my intentions36, she told me that she would only marry the
strongest man in Winnipeg. As you can imagine, I was no Hercules, but I was determined. Being
a book-worm37, I had read about volcanoes and Hollywood films. So, I saved enough money to
travel to L.A... I came back with a real picture of me holding the world’s biggest boulder. We
got married that same year!”
Are you surprised? Lava stone is very light and is often used in movies to impress audiences.
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