Download Predicting and preparing for volcanoes

Volcanos
When a volcano in Iceland erupted in April, it caused huge disruption in parts of
Europe.
Lots of British tourists were stranded abroad and couldn't get home because it
was too dangerous for planes to fly through the huge ash cloud the volcano
emitted.
Volcanoes: the facts
• A volcano is a piece of land (usually a mountain) which molten rock (magma)
erupts from
• They're like safety valves that release the pressure that builds up inside the
Earth
• 300 million, or 1 in 20, people in the world live
within 'danger range' of an active volcano
Lava that flows from
• About 1,500 different volcanoes have erupted over volcanoes is so hot it
the past 10,000 years, but only about 60 erupt each burns everything in its
year. On any given day, there are about 20 volcanoes path
erupting somewhere in the world
• Some volcanoes are under the sea
• In the past 500 years, 250,000 people have been killed as a direct result of
volcanic eruptions
• The Earth's rigid outer layer is made from huge slabs
called tectonic plates that fit together like a jigsaw
puzzle. When two of them collide, one is pushed
below the other, causing melting at depth that leads
to volcanic eruptions when the molten rock (magma)
finds its way to the surface
• Volcanoes can also erupt at sites where two plates
are being pulled apart, like Iceland, or at special 'hot The world's largest active
volcano is Mauna Loa in
spots' like Hawaii
• The world's largest active volcano is Mauna Loa in Hawaii
Hawaii
• Lava flows can reach 1,250 degrees Celsius and burn everything in their path - a
glass thermometer would just melt if you tried to measure it
• Ash and toxins from eruptions can be dangerous
and cause lung damage, particularly for babies and
old people
• People often set up home on the slopes of
volcanoes because the soil there is rich and fertile
• 90% of all volcanoes are in the 'Ring of Fire' which is
along the edges of the Pacific Ocean
• The word volcano probably comes from the name of The volcanic eruption in
Iceland
Vulcano, which is an island off Sicily named after
Vulcan, the Roman God of Fire
The eruption in Iceland
• It's in south-west Iceland, it's near the sea, and it covers around 40 square miles
• It's 1,666 metres tall
• The volcano has erupted TWICE. Once in March 2010, which meant 500 people
were evacuated from the area, and then again in April (much more powerful than
the March eruption) which caused Europe so much disruption
• It's underneath a glacier which causes two
problems: 1) flooding when the heat from the volcano
melts all the ice, which is why those people were
evacuated, and 2) it makes the eruption highly
explosive. When the water leaked into the insides of
the volcano, the magma turned the water to steam.
The resulting explosion shattered the magma into tiny
The Eyjafjallajökull
fragments called 'volcanic ash' and shot them high
volcano erupts in Iceland
into the sky
• The ash cloud reached 55,000 feet
• Iceland is a volcanic hot spot on the Mid-Atlantic Ridge, which is the dividing
line between the Eurasian and North American plates
• There are 35 active volcanoes in Iceland
• There is another volcano nearby and people are worried this eruption could set
it off. It's called Katla
The disruption caused by the volcano
• British airspace was closed for six days, which meant no planes could fly at all
• 120,000-150,000 Brits were stranded abroad,
including loads of teachers and pupils on their Easter
holidays
• The disruption has cost airlines across the whole
world £1.1 billion
• 1.2 million passengers a day were affected by the
closure
British airspace was closed
for six days
CBBC - Newsround - Volcanoes (2011)
More on the impact on residents
Authorities moved 800 residents away from the Eyjafjallajokull glacier as rivers rose by up to
three metres. Rognvaldur Olafsson, a chief inspector for the Icelandic Civil Protection
Agency, said no lives or properties were in immediate danger.
Emergency officials and scientists said the eruption under the ice cap was 10 to 20 times
more powerful than an eruption that happened in the area late last month, and carried a
much greater risk of widespread flooding.
"This is a very much more violent eruption because it's interacting with ice and water," said
Andy Russell, an expert in glacial flooding at the University of Newcastle in northern
England.
"It becomes much more explosive, instead of a nice lava flow oozing out of the ground."
The volcano, about 120 kilometres east of Reykjavik, erupted March 20 after almost 200
years of silence.
Pall Einarsson, a geophysicist at the University of Iceland, said magma was melting a hole in
the thick ice covering the volcano's crater, sending water coursing down the glacier.
Iceland's main coastal ring road was closed near the volcano, and workers smashed a hole in
the highway in a bid to give the rushing water a clear route to the coast and prevent a major
bridge from being swept away
CBC News World (2010)
Predicting and preparing for volcanoes
It's not possible to prevent earthquakes and volcanic eruptions. However,
careful management of these hazards can minimise the damage that they
cause. Prediction is the most important aspect of this, as this gives people
time to evacuate the area and make preparations for the event.
Unfortunately volcanic eruptions and earthquakes cannot be prevented.
Managing hazards such as earthquakes and volcanoes can be done by:
prediction and preparation.
Predicting eruptions
As a volcano becomes active, it gives off a number of warning signs. These
warning signs are picked up by volcanologists (experts who study volcanoes)
and the volcano is monitored.
Key techniques for monitoring a volcano
Warning signs
Monitoring techniques
Hundreds of small earthquakes are caused
as magma rises up through cracks in the
Earth's crust.
Seismometers are used to detect
earthquakes.
Temperatures around the volcano rise as
activity increases.
Thermal imaging techniques and
satellite cameras can be used to
detect heat around a volcano.
When a volcano is close to erupting it starts Gas samples may be taken and
to release gases. The higher the sulfur
chemical sensors used to
measure sulfur levels.
content of these gases, the closer the
volcano is to erupting.
The techniques available for predicting and monitoring volcanic activity are
becoming increasingly accurate. Volcanoes such as Mount St Helens in the
USA and Mount Etna in Italy are closely monitored at all times. This is because
they have been active in recent years and people who live nearby would
benefit from early-warning signs of an eruption. However, as well as
prediction, people need to be prepared for an eruption.
Preparing for an eruption
A detailed plan is needed for dealing with a possible eruption. Everyone who
could be affected needs to know the plan and what they should do if it needs
to be put into action. Planning for a volcanic eruption includes:




creating an exclusion zone around the volcano
being ready and able to evacuate residents
having an emergency supply of basic provisions, such as food
funds need to be available to deal with the emergency and a good
communication system needs to be in place
BBC GCSE Bitesize (2014)
Some safety procedures when a volcano erupts
• If you live near an active volcano, keep goggles and a mask in an emergency
kit, along with a flashlight and a working, battery-operated radio.
• Know your evacuation route. Keep gas in your car.
If a Volcano Erupts in Your Area
• Evacuate only as recommended by authorities to stay clear of lava, mud
flows, and flying rocks and debris.
• Avoid river areas and low-lying regions.
• Before you leave the house, change into long-sleeved shirts and long pants
and use goggles or eyeglasses, not contacts. Wear an emergency mask or hold
a damp cloth over your face.
• If you are not evacuating, close windows and doors and block chimneys and
other vents, to prevent ash from coming into the house.
• Be aware that ash may put excess weight on your roof and need to be swept
away. Wear protection during cleanups.
• Ash can damage engines and metal parts, so avoid driving. If you must drive,
stay below 35 miles (56 kilometers) an hour.
© 1996-2014 National Geographic Society