What is like living
near a volcano?
1. What is it like most of
the time?
2. What happens when it
erupts?
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Why do people live near volcanoes?
At first it may seem odd that people would want
to live close to a volcano or any tectonic activity.
After all, volcanoes have a nasty habit of
exploding, discharging liquid rock, ash, poisonous
gasses, red hot clouds of embers, and generally
doing things that kill people.
Yet, throughout history, people have
deliberately chosen to risk all those hazards and
live near them, even on the slopes of active
volcanoes that have erupted within living
memory.
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They chose to live close to volcanoes because
they felt that the advantages outweighed the
disadvantages.
Most volcanoes are perfectly safe for long
periods in between eruptions, and those that do
erupt more frequently are usually thought of, by
the people who live there, as being predictable.
Today, about 500 million people live on or close
to volcanoes.
We even have major cities close to active
volcanoes. Popocatapetl is a volcanic mountain
less than 50 miles from Mexico City in Mexico.
In short, the main things that attract people to
live near active volcanoes are minerals,
geothermal energy, fertile soils and tourism.
Lets look at each one...
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Minerals
Magna rising from deep inside
the earth contains a range of
minerals.
As the rock cools, minerals are
precipitated out and, due to
processes like the movement of superheated water and
gasses through the rock, different minerals are
precipitated at different locations.
This means that minerals such as tin, silver, gold, copper
and even diamonds can be found in volcanic rocks.
Most of the metallic minerals mined around the world,
particularly copper, gold, silver, lead and zinc are
associated with rocks found deep below extinct
volcanoes.
Hot gasses escaping through vents of active volcanoes
also bring minerals to the surface, notably sulphur, which
collects around the vents as it condenses and solidifies.
Locals collect the sulphur and sell it.
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Geothermal Energy
Geothermal energy means heat energy from the
earth.
It's unusual to use the heat directly, by building
your house on top of a steam vent for example,
because it's unpredictable, dangerous and
messy.
The heat from underground steam is used to
drive turbines and produce electricity, or to
heat water supplies that are then used to
provide household heating and hot water.
Where steam doesn't naturally occur it is
possible to drill several deep holes into very hot
rocks, pump cool water down one hole and
extract steam from another hole close by.
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Geothermal Energy
Countries such as
Iceland make extensive
use of geothermal
power, with
approximately two thirds
of Iceland's electricity
coming from steam
powered turbines.
New Zealand and to a
lesser extent, Japan,
also make effective use
of geothermal energy.
Iceland has over 200
volcanoes and 800 hot
springs
26% of Iceland’s electricity
comes from Geothermal
Power.
Reykjavik is said to be “the
most unpolluted capital in
Europe.”
It’s true - the city is
absolutely pristine. The air
is crystal clear.
The geothermal electricity
generation has a lot to do
with this.
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Other uses of Geothermal power in
Iceland
It is also used for
recreational purposes
Blaa Lonio - The Blue
Lagoon. In the middle
of this huge lava field
sits this pool of
seawater naturally
heated by the
geothermal activity
below the surface
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Southeast of Reykjavik,
the town of Hveragerdi
serves as a geothermal
farming centre for the
capital.
Puffs of steam coming
out of the ground all
over the place.
There were greenhouses everywhere, often
surrounded by steaming cracks in the ground.
The extreme climate of Iceland is actually able
to produce much in the way of tropical fruits
and vegetables with the help of geothermal
steam.
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Fertile Soils
Volcanic rocks are rich in minerals, but when the rocks
are fresh the minerals are not available to plants.
The rocks need thousands of years to become
weathered and broken down before they form rich soils.
When they do become soils though, they form some of
the richest ones on the planet.
The Naples area, which includes Mount Vesuvius, has
such rich soils thanks to two large eruptions 35,000 and
12000 years ago. Both eruptions produced very thick
deposits of ash and broken rocks which have weathered
to rich soils.
Today, the area is intensively cultivated and produces
grapes, vegetables, orange and lemon trees, herbs,
flowers and has become a major tomato growing region
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Tourism
Volcanoes attract millions of visitors every
year, for different reasons.
As an example of the wilder side of nature,
there are few things that can beat seeing an
erupting volcano blowing red hot ash and rock
thousands of feet into the air.
Even the less active ones that are just puffing
out steam and smoke are impressive sights
and attract tourists from around the world.
Around the volcano may be warm bathing
lakes, hot springs, bubbling mud pools and
steam vents.
Geysers are always popular tourist
attractions, such as Old Faithful in the
Yellowstone National Park, USA. Old Faithful
is such a popular tourist feature that it even
has its own 24 hour Old Faithful webcam.
This one is in
New Zealand
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Tourism
Iceland markets itself as a land of fire and ice,
attracting tourists with a mix of volcanoes and glaciers,
often both in the same place.
The wild, raw and barren volcanic landscapes also attract
tourists who want to see what the early planet may have
looked like.
Tourism creates jobs in shops, restaurants, hotels and
tourist centres / national parks.
Locals economies can profit from volcanism throughout
the year, whereas skiing, for example, has only a limited
winter season.
In Uganda, a country trying hard to increase its tourist
industry, the volcanic region around Mt Elgon is being
heavily promoted for it's landscape, huge waterfalls,
wildlife, climbing and hiking and its remote 'get away
from it all' location.
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Building Materials
Blocks of lava are
used for building
materials
Granite is a volcanic
rock
Ash is used in cement
to build with.
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They stay there because there is
nowhere else to go – it is home
Land is cheap in volcanic and earthquake zones.
Some people are too poor to leave their home
(especially in LEDCs) – also poor education does
not explain why they should move further away
Even when people can afford to leave the area
they may be too attached to their homes to
leave. Their families have been there for
generations.
And there are so many people living in these
dangerous areas, that it would difficult if not
impossible to re-house them, especially as many
areas that provide food for so many other
people.
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So living near a volcano can have its
advantages, but how do you cope with
the danger?
Scientists can often find clues about past
eruptions by studying the deposits left
behind. Areas affected by lava flows etc
can be mapped, making disaster planning
more effective.
In addition to this type of long-range
forecasting, scientists are becoming more
and more skilled at spotting the warning
signs of an eruption.
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Warning Signs
Before an eruption, magma moves into the area
beneath the volcano and collects in a magma
chamber, or reservoir.
As it comes closer to the surface, the magma
releases gases.
These events can offer valuable clues about the
likelihood of an eruption.
For example, the movement of magma produces
small earthquakes and vibrations
Magma gathering in a chamber causes slight
swelling of the volcano's slopes.
Gases released near the volcano can be
measured for changes in quantity and makeup. 15
Monitoring Methods
A number of tools can be used to record these
warning signs.
Seismographs can detect small earthquakes,
while tiltmeters and geodimeters can measure
the subtle swelling of a volcano.
Spectrometers can measure amounts of sulfur
dioxide
a telltale gas that is released in increasing quantities
before an eruption.
Using these and other tools, it's possible to
closely monitor activity at an awakening volcano.
Volcanologists are becoming very skilled at
predicting the likelihood of an eruption.
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But ….
……. it's very difficult to pinpoint exactly when
an eruption will happen.
Often, moving magma doesn't result in an
eruption at all, but instead cools below the
surface.
Monitoring potential eruptions is expensive.
With many volcanoes erupting only every few
hundred or thousand years, it's not possible to
monitor every site.
Volcanic eruptions don't occur without warning,
however. If we set up monitoring devices, we
should not be caught off guard by disastrous
eruptions.
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So you are living in
a volcanic zone?
What can you do to stay
safe?
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Your plan should include 4 parts
1. What do I need to know and have ready
in case an eruption should happen?
2. What will I do if an eruption is
predicted?
3. What will I do during an eruption?
4. What will I do after an eruption?
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OK – you live in a
volcanic area
What do you need to know
and have ready in case an
eruption should happen?
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Suggestions include
Learn about your community warning systems.
Be prepared for these disasters that can be spawned by volcanoes.
Earthquakes, Flash floods, Landslides and mudflows, Thunderstorms,
Tsunamis
Make evacuation plans. You want to get to high ground away from
the eruption. Plan a route out and have a backup route in mind.
Develop an emergency communication plan.
In case family members are separated from one another during a
volcanic eruption, have a plan for getting back together. Ask an out-ofstate relative or friend to serve as the "family contact." Make sure
everyone knows the name, address, and phone number of the contact
person.
Have disaster supplies on hand.
Flashlight and extra batteries, Portable, battery-operated radio and
extra batteries, First aid kit and manual, Emergency food and water,
Non-electric can opener, Essential medicine, Cash and credit cards,
Sturdy shoes, A pair of goggles and a throw-away breathing mask for
each member of the household.
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The volcano alert has
been made
TV and Radio are
telling people to
evacuate URGENTLY
The eruption could be any time soon!
You have a plan – but what could go
wrong with it?
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Some ideas
Although it may seem safe to stay at home and wait out
an eruption, doing so could be very dangerous. The rock
debris from a volcano can break windows and set
buildings on fire. Stay safe. Follow authorities'
instructions and leave the area before the disaster
begins.
Follow the evacuation order issued by authorities. Avoid areas downwind of the volcano.
Mudflows or Lahars : are powerful "rivers" of mud that
can move faster than people can walk or run and occur
when rain falls through ash-carrying clouds or when
rivers are dammed during an eruption.
When you approach a bridge, first look upstream. If a
mudflow is approaching or moving beneath the bridge, do
not cross the bridge. The power of the mudflow can
destroy a bridge very quickly.
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If eruption happens before you get away
If caught indoors:
Close all windows, doors, and dampers.
Put all machinery inside a garage or barn.
Bring animals and livestock into closed shelters.
If trapped outdoors:
Seek shelter indoors.
If caught in a rock fall, roll into a ball to protect head.
Avoid low-lying area where poisonous gases can collect and flash
floods can be most dangerous.
If caught near a stream, beware of mudflows.
Protect yourself:
Wear long sleeved shirts and pants.
Use goggles to protect eyes.
Use a dust-mask or hold a damp cloth over face to help
breathing.
Keep car or truck engines off.
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Afterwards
Listen to a battery-powered radio or television for the
latest emergency information.
Stay away from volcanic ash fall.
When outside:
Cover your mouth and nose. A number of victims of the Mount
St. Helens volcano died from inhaling ash.
Wear goggles to protect your eyes.
Keep skin covered to avoid irritation or burns.
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.
Avoid driving in heavy ash fall. Driving will stir up more
ash that can clog engines and stall vehicles.
Clear roofs of ash fall. Ash fall is very heavy and can
cause buildings to collapse.
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Homework
Imagine you are an advertising executive and
you want to attract people to visit or live on
your volcano (you might like to use your volcano
from last week?)
In a 3-slide PowerPoint
Explain
why it is really the one place they would like to come
to
how they will protected by monitoring
how they can prepare to survive any disaster
Keep it brief and punchy – this is an advert
remember –
Don’t let the font size go below size 24
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