Eyjafjallajöku
ll April 2010, Iceland.
The Eyjafjallajökull volcano
What’s it look like?
There it is! A shield volcano!
Where is it?
Volcano location
The wider landscape of
Eyjafjallajökull ….
What were the effects?
• Volcanic eruptions are not uncommon in Iceland – one occurs every five or so years but in April 2010 the largest eruption of Eyjafjallajökull in history occurred.
• With wind direction blowing southerly, the ash cloud spread into northern Europe causing some 100,000 flights to be cancelled and some 7 million people to be stranded.
• Although the volcano actually started erupting in late March 2010, on April the 14th it started giving out huge amounts of ash into the atmosphere (some scientists estimate 140 million cubic metres).
• Scientists are particularly worried because Eyjafjallajökull shares a magma chamber with its nearby sister volcano Katla, which historically has always erupted soon after Eyjafjallajökull.
• As Katla is much bigger than Eyjafjallajökull it has the potential to do huge amounts of damage…luckily it’s not gone off…yet.
• But luckily scientists are keeping an eye on it and it is one of the most monitored volcanoes in the world now.
Roads washed away Total loses to Iceland of £80million Local water supplies were contaminated
with fluoride
100,000 flights cancelled over 8 days Sporting events were cancelled or affected
due to cancelled flights
Eyjafjallajökull has become a new Icelandic
tourist attraction with its own visitors
centre giving a boost to tourism.
It felt like day turned to night due to the
ash blocking out the sun
A Jökulhlaup or GLOF (glacial lake outburst
flood) was caused when the glacier on top
of the volcano melted
Rocks given out by the volcano can be used
for building
Homes and roads damaged and services
(like schools!) disrupted
Lava and ash are rich in nutrients making
the soils in volcanic areas very fertile and
good for agricultural use
Crops were damaged by ash and unable to
be grow
Rescuers wore face masks to prevent them
choking on the clouds of ash
Industries were affected by a lack of
imported raw materials for example fresh
food imports stopped.
The Jökulhlaup caused bridges to become
warped and collapse
Jewellery has been created from the ash
given out and is now a big hit with tourists.
Roads were reconstructed with bridges
being strengthened and raised higher.
The temperature of the nearby river rose
to between 50°C and 60°C killing fish
within the river.
Local flood defences needed rebuilding 500 people were evacuated from homes
and hotels nearby
Aircraft now are able to fly through much
thicker ash clouds than in 2010.
The mountain and glacier and now one of
the most monitored sites in Europe.
Other countries exporting in to, and
around, northern Europe were affected –
for example Kenya had to throw away 10
million flowers that were due to be
exported to Europe, while Italy lost
$14million per day as it was unable to
export anything.
The cost to airlines was well over $1.7
billion
Over to you…
1. Complete the hexagon revision sheet for
Eyjafjallajökull.
2. Draw a diagram of what a shield volcano looks like
3. Explain how a shield volcano is different to a
composite volcano.
Eyjafjallajökull
Causes Details / Facts
Primary Effects
Secondary Effects
Responses
Location
Supervolcanoes
• Supervolcanoes are smaller in number, there’s only
7 that have been discovered, as shown in the map
below, but much bigger in terms of size and impact.
• They are located mostly on destructive plate
boundaries, but are
also located in hot
spots – areas where
magma rises up in
cracks in the mantle.
How Supervolcanoes are created
Where is Yellowstone?
• Yellowstone National Park is home to a supervolcano
which last erupted 640,000+ years ago. Some
scientists believe that this last eruption triggered an
ice age.
• The Yellowstone Caldera sits on a hotspot
underneath the North American Plate. 3 eruptions
have occurred in the last 2m years – meaning (some
scientists believe) it is due to erupt soon
(geologically speaking that could by anytime from
now to the next couple of thousands of years).
• The magma chamber is 80km long, 40km wide and
8km deep. If it erupts it would eject 5,000km³ of
material (5x the minimum size for a supervolcano).
• There are signs of increasing activity within the
caldera – the geysers are becoming more active and
the ground has risen 70cms in places. However no-
one knows if this is just part of the natural cycle.
If it erupts It is predicted
that if Yellowstone erupts
then: • 10,000km² of land would be blasted away.
• 87,000 people would die – some from their injuries in the blast, others from the effects of lack of food and water. 1 in 3 people affected by the ash would die.
• 15cms of ash would cover buildings within 1,000km.
• The ash would affect transport so there would be no planes.
• Electricity and water supplies – major impact on our ability to survive in the USA in particular but ash would have a more widespread effect eg UK.
If it erupts It is predicted
that if Yellowstone erupts
then: • Lahars would form where the ash mixes with water and would
flow across the land and then set like concrete destroying farmland and making towns uninhabitable.
• The ash would reach the UK after 5 days and affect us here.
• Global climates would change because of the ash and gases ejected into the atmosphere. Temperatures are likely to fall by 12-15°C.
• Parts of Europe would see constant snow cover for 3 years. Monsoon rains would fail affecting Asia.
• Crops would fail causing food shortages - it is estimated that 40% of the global population would face severe shortages. There would be loss of plant and animal species.
Over to you…
1. Describe the distribution (location!) of
supervolcanoes.
2. Explain in no more than 50 words how a
Supervolcano is formed.
3. Complete the revision sheet for Yellowstone
National Park
Yellowstone Impacts
Short Term Impacts Long Term Impacts Local / Regional Impacts National / International Impacts
Where is Haiti?
Gulf of Mexico
Pacific
Atlantic
Caribbean
Mexico
Belize
Guatemala
Columbia Venezuela
Guyana
French Guiana
Cuba
Jamaica Dominican Republic
Key Info
Haiti
Main Location Port-au-Prince
Date, time 12/01/2010, 16:53pm
Magnitude 7.0
Distance of epicentre from main location 13km South West
Focus 13km
Summary Statistics
316,000 people killed, 300,000 injured, 1.3 million
displaced, 97,294 houses destroyed and 188,383
damaged.
Haiti Info
Haiti shares the island
Hispaniola with the Dominican
Republic in the Caribbean. The
Haiti earthquake was caused
by the North American Plate
sliding past the Caribbean
Plate at a conservative plate
margin.
Both the North American plate
and the Caribbean plate move
in the same direction, but one
moves faster than the
other. This causes pressure to
build up.
The friction between the two
tectonic plates eventually
released causing a magnitude
7 earthquake on the Richter
Scale with an epicentre 16 kms
south west of Port-au-Prince
and a shallow focus of 5 miles.
Haiti was struck by an
earthquake 16:53 (4:53pm)
local time on Tuesday 12
January 2010. At the time
there were 3 million people
living in the capital city Port-
au-Prince. Most people lived in
slums.
The earthquake struck in a
densely populated area killing
250,000 people and 1.3 million
people were made
homeless. 3 million people
were affected by the
earthquake.
250,000 homes and 30,000
other buildings, including the
President’s Palace and 60% of
government buildings, were
either destroyed or badly
damaged.
The estimated cost of damage
was $14 billion. Transport and
communication links were also
badly damaged by the
earthquake
Hospitals (50+) and schools
(1,300+) were badly damaged,
as was the airport’s control
tower
The main prison was destroyed
and 4,000 inmates escaped
1 in 5 people (20%) lost their
jobs because so many buildings
were destroyed. Haiti’s largest
industry, clothing was one of
the worst affected
The large number of deaths
meant that hospitals and
morgues became full and
bodies then had to be piled up
on the streets
The large number of bodies left
lining the streets meant that
diseases, especially cholera,
became a serious problem.
It was difficult getting aid into
the area because of the
damage to the airport and
generally poor management of
the situation. Aid was left at
the airport and the port was
also badly damaged.
People were squashed into
shanty towns or onto the
streets because their homes
had been destroyed leading to
poor sanitation and health, and
looting became a real problem
$100 million in aid given by the
USA and $330 million by the
European Union. 1 million
people had to live in temporary
camps. 600,000 people moved
away from their homes and to
countryside areas in Haiti.
4.3 million people provided
with food rations in the weeks
following the earthquake
Over 115,000 tents had to be
provided for people to live in.
There were many internally
displaced people (IDP).
Lack of immediate aid through
poor planning, management
and access meant that people
had to try and rescue each
other
Medical teams treated people
in make shift hospitals
organised mainly by the red
cross. Many people had to try
and dig out survivors with their
hands.
After 1 year re-building of
homes and services had begun
but it is believed there are still
1,300 camps full of people
without homes.
Cash for work programs have
been introduced; paying
Haitian people to rebuild and
clear away rubble.
Where is New Zealand?
What type of plate boundary is
it on?
• But some parts of the plate are moving away from each other too – so it’s on a destructive AND constructive plate boundary.
What was it like?
Over to you
1. Separately describe the location of both Haiti and
New Zealand.
2. Explain what type of plate boundary they are on.
3. Complete the revision spider diagram handouts.
a) Highlight in one colour the similarities between the two
earthquakes.
b) Highlight in a different colour the differences between
the two earthquakes.
Haiti
Causes
Responses
Primary Effects
Secondary Effects
New
Zealand
The structure of the Earth
• The crust is where we live and it’s
divided into seven major tectonic
plates plus about 40 smaller
ones.
• There are two different types of
crust – continental crust and
oceanic crust which have
different characteristics.
• Tectonic plates float on the semi molten rock of the asthenosphere, on average the plates move at about 5cms a year in the direction of the convection currents below them in the mantle.
• Convection currents are the movement of the heated up mantle away from the core before then cooling and sinking again.
• Plate margins or boundaries are where tectonic plates meet or pull apart because of these convection currents.
• The mantle has the hottest rock when it is nearest to the core (5,000°C). It is coolest near to the surface but even then the rock is semi molten here - just underneath the crust in the area. This is known as the asthenosphere.
• The area heating all of these up is the core - a dense area made up of rocks containing iron and nickel. The inner core is solid and has a temperature of 6,000°C, as hot as the surface of the sun.
• The convection currents are created by the heat of the outer core – about 5,000°C.
Oceanic Crust Vs
• Oceanic Crust is:
– Newer – most is less than 200
million years old
– Denser – so therefore can
sink
– Can be renewed and
destroyed
• Continental Crust is:
– Older – most is over 1,500
million years old.
– Less dense – so cannot sink
– Cannot be renewed or
destroyed
Continental Crust
Conservative
• At conservative plate margins two plates are sliding past each other in slightly different directions and at slightly different speeds.
• They do not move smoothly and tend to get stuck.
• Pressure builds up along the fault until one plate jerks past the other as the pressure is released – an earthquake.
• The movement has caused the land to become ridged and crumpled.
• There is no volcanic activity because land is neither being created or destroyed.
Constructive
• Constructive plate boundaries are usually found at two oceanic crusts that are moving apart.
• As the plates move apart the gap in the seafloor between them is filled with magma rising up from the mantle below. This creates an underwater volcanic ridge.
• An example of this is the Atlantic Ocean which is getting wider as the seafloor is spreading.
• Sometimes the volcanoes grow high enough to reach the surface and so create volcanic islands like Iceland. It too is growing wider as magma fills in the gap as the plates move apart.
• Shield volcanoes are created here.
Collision
• At collision margins two continental crusts are forced together.
• Neither can be destroyed so the rocks between them are forced upwards under huge pressure.
• It is this forcing upwards that can cause mountain ranges and large earthquakes such as the 2005 Pakistan earthquake.
Destructive
• At destructive plate margins two plates are
moving together – the oceanic and continental
crust meet.
• Where this happens the oceanic crust which is
denser than the continental crust is forced to
sink under the continental plate.
• The oceanic crust is pushed down (subducted)
into the mantle in a place called the subduction
zone.
• The oceanic plate does not slide smoothly under
the continental plate. It moves in a series of
jerks because of friction and so there is a build
up of pressure in the subduction zone.
• An earthquake is caused when this pressure is
released all of a sudden. They can be very high
magnitude.
Destructive
• Pressure builds up in the magma
which will escape through any lines
or cracks of weakness in rocks of
the continental crust. When it comes
to the surface it erupts as a volcano.
• The most common type of volcano
on a destructive margin is a
composite volcanoes which are very
explosive because the lava is acidic
and contains water and gases.
• A deep ocean and fold mountains
are created here.
Collision margin: Two continental
plates collide, they are both the same
density and so they crash and the
land buckles into fold mountains. The
Indo-Australian plate is colliding with
the Eurasian plate and has formed
the Himalayas.
Destructive margin:Subduction
Nazca plate (oceanic crust) is
being subducted under the South
American plate (continental
crust).
Constructive margin: Mid Atlantic Ridge is
marked by an underwater chain of volcanoes
and fissures (cracks) where the North
American plate is being pulled away from the
Eurasian plate. Iceland has been formed
where these volcanoes have built up to the
surface.
Conservative margin: The
North American plate and the
Pacific plate are sliding past
each other. This is the San
Andreas Fault.
Over to you…
1. Draw a diagram of the structure of the earth.
Annotate all around it what each area is like.
2. Create a table of what the differences between
oceanic and continental crust are. Give at least 3
reasons why / when these become important.
3. Explain in no more than 50 words EACH how shield
volcanoes, composite volcanoes and earthquakes
are formed.
What causes a tsunami?
• A tsunami (a Japanese word meaning harbour wave)
is a massive movement of water caused often by
earthquakes that take place underwater or volcanic
eruptions.
• It can also be created by landslides into water, or
underwater explosions.
• The earthquake (at a destructive or conservative
plate boundary) sends out a huge amount of energy
through the sea; and at a destructive plate boundary
– the plates themselves move; this causes the water
to move out in all directions.
• These waves move out increasing in length to
around 200km and speed, up to 800km a hour but
start off relatively small in height, at about 1 metre
high.
• As the waves near the coast and the sea shallows
the amount of water in contact with the base of the
sea the amount of friction increases and the waves
slow down in speed to about 80km an hour.
• As the waves slow down, more and more of them
bunch up together and raise up in height – from
anywhere between 10m and 30m – this gives the
impression that the sea is retreating, when in reality
the water is being pulled back to add to the giant
tsunami wave.
Our case study…
• Is the 2004 Boxing Day Tsunami.
• It was caused by an earthquake measuring between 9.1 and 9.3 on the Richter scale
• It killed over 230,000 people in fourteen countries.
• It was to be the fifth deadliest earthquake in history.
http://upload.wikimedia.org/wikipedia/commons/8/89/2004_Indian_Ocean_earthquake_-_affected_countries.png
• Scientists have predicted that the power unleashed
by the wave was similar to that of 1500 atomic bombs
being released.
• It was made worse was the fact that countries in the
Indian Ocean had no tsunami warning system (unlike
places like Hawaii for example) as it was too
expensive for them to afford.
• Waves reached a maximum height of 24 metres in
Ache province in Indonesia,
the worse hit of all the countries.
• On average the height of the tsunami waves at
their worse were around 10m.
http://upload.wikimedia.org/wikipedia/commons/5/57/Tsunami_size_scale_26Dec2004.png
Over to you…
1. Describe where the Boxing Day Tsunami hit.
2. Explain what caused the Boxing Day Tsunami and
why it was so bad (hint – link to development here)
3. Complete the hexagon revision sheet.
Boxing Day Tsunami
Causes Details / Facts
Primary Effects
Secondary Effects
Responses
Location
Glacial landforms
• Are made up of processes including:
• Accumulation – when snow gathers at the top of a mountain and fails to melt. Over time through compression this will become glacial ice.
• Compression – when snow is pushed down under the weight of fresh snow having fallen on top of it to create glacial ice.
• Freeze Thaw - Water in a crack freezes and expands. This puts pressure on surrounding rock. It thaws and contracts repeatedly to weaken joints in the rock. The rock eventually breaks off.
• Abrasion - Abrasion is the process where rock fragments in the ice grind against the rock over which the ice is moving (like rough sandpaper) wearing away the land.
• Plucking - Plucking is where meltwater at the base of the glacier freezes on the rock surface. As the glacier moves forward it extracts pieces from the rock surface.
Types of Moraine
• Lateral moraine is deposited on both sides of a valley.
• Medial moraine is formed when two glaciers meet and is deposited in the centre (middle) of a valley.
• Ground moraine is deposited unevenly across a valley floor as a glacier retreats.
• Terminal moraine is deposited at the snout (front) of a glacier and marks the furthest point reached.
• name these?
Can you
name
and explain
these?
U Shaped Valleys /
Glacial Troughs
• Are a glacial landform of erosion.
• Created over thousands of years.
• Found in Wales and the Lake District.
U Shaped Valleys – Before the
Ice Age
U Shaped Valleys – During the
Ice Age
U Shaped Valleys – After the
Ice Age
Corrie
Arm chair shaped hollow that snow and ice accumulate in, carved by a glacier
Tarn formed in the deepest part of the corrie as it was scooped out by erosion (abrasion)
Steep back wall caused by freeze-thaw and plucking
Rock lip at the edge of the corrie formed by deposits as the glacier rotated out of the basin
Pyramidal Peak: Steep mountain formed as three corries retreat backwards
Corrie back-wall steepened by freeze-thaw and abrasion
Pyramidal Peak
Ribbon Lake: Long, thin lake
Area of softer rock found in the middle of two areas of harder rock
As the glacier melted water got stuck in areas previously eroded by abrasion.
Arete
Sharp knife edged ridge between TWO corries.
Formed as two corries are eroded and weathered backwards.
Corrie
An arm chair shaped hollow widened and deepened by a glacier.
Steep back wall created by freeze-thaw and plucking
Named example
Striding Edge on Helvellyn in the Lake District
A hanging valley is a smaller side valley left 'hanging' above the main u-shaped valley.
A waterfall is often seen as the smaller valley meets the bigger one
The bigger valley is caused by a larger glacier eroding down further.
Where the smaller hanging valley has been cut is known as a truncated spur.
Drumlins
• Drumlins are formed of glacial till – the name
given to moraine after the ice has melted.
• They are long features that can reach a
kilometre or more in length, 500m or so in
width and over 50m in height.
Drumlins form when…
• Moraine collects in front of an immovable object
before spilling over the top and down behind the
immovable object.
• The glacier shapes and moulds the drumlin with a
blunt end facing up valley and a pointed tail end
facing down the valley, in the direction that the ice
travelled.
• When the glacier melts a drumlin is left behind.
• An erratic is a boulder
that is different to the
bedrock upon which it
is sitting.
• They have been
transported and
deposited by a glacier.
• Therefore erratics are
useful indicators of
patterns of former ice
flow.
Over to you…
1. Draw, define and (where necessary) explain the
different processes that take place in glacial
environments.
2. Choose three different landforms of erosion and
explain how they are created.
3. Choose one landform of deposition and explain
how it is created.
A Retreating Glacier – The
Rhone Glacier
• Our example is the Rhone Glacier in Switzerland, it’s
in the south of the country and is one of a number of
glaciers in Switzerland. It is also a good example of
one that is retreating quickly, and the potential
impact of this on the surrounding area.
• Since 1860 the thickness of the Rhone glacier has
reduced by 34m.
• The length of the glacier changes over the course of
the year (with it retreating in the summer, and
advancing in the winter) shown by the red line.
• The overall length of the glacier (shown by the green
line) shows a significant reduction, around 1.2km
has been lost.
• The fastest reduction has been from 1950 onwards
(shown by the steeper, declining green line).
Year
Len
gth
of
Gla
cier
(M
etre
s)
//upload.wikimedia.org/wikipedia/commons/4/48/Rhone_glacier_stats.svg
• Glacial retreat is particularly important in
Switzerland, for starters if it continues there is the
potential in the short term for catastrophic flooding,
while long term the tourist industry could suffer a
significant drop.
• The glacier is also hugely important for
Switzerland’s water and electricity supply, as during
the summer much of the melted ice is either treated
and used for drinking water, or used to produce
around half of Switzerland’s energy.
• Scientists have suggested that glacial retreat has been causes by the warming up of the earth, with an increase in temperature of 0.74°C since 1900.
• This may be in part may be linked to the increased use of fossil fuels (like oil and coal) or the increased emissions (releasing of) carbon dioxide in the atmosphere, which has caused a greenhouse effect, and raised temperatures in the world.
• As a result it is too warm for snow to fall, instead falling as rain, meaning a lack of glacial ice being created, and the chance for flooding increased.
Over to you…
1. Describe the location of the Rhone glacier.
2. Describe why it is important to the area.
3. Explain how you know it is retreating referring to
specific evidence / examples.
4. Explain the causes of its retreat.
Chamonix and the Alps
• Are a good example of tourism in a mountainous
area (for Ice on the land) and uses of a fold mountain
(for Restless Earth).
• One BIG case study – two uses.
• Result eh?
The Alps!
Over to you…
1. How are the Alps used? Make a spider diagram of all the different uses on some A3 paper – use different colours to show each of the different uses and add detail from each use.
2. What can tourists do in Chamonix? Use the information sheets to help you.
3. What problems does living in the Alps have?
4. How have people overcome problems with living in mountainous areas?