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Plate Tectonics Revision
By Hannah Jeanes…read more

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Also called Plates moving
tensional or slowly apart Conservative
Also called
Often Plates slide past
Magma rises underwater, each other causing
from mantle, can form earthquakes
and solidifies volcanic
Earthquakes and forming islands
volcanoes igneous rock
Plate Boundaries
Same type of crust The Earth
·Forced upwards and fold
mountains created Plates
Made up of
oceanic or
Destructive four layers
Oceanic and Continental Crust Split into plates
Plate moving
towards each ·Oceanic plate is denser and thinner
other ·Oceanic is subducted at subduction zone Plates move due to
convection currents in the
·Oceanic plate melts, forming magma
Also called earth's mantle
compressional or ·Earthquakes as plates move
convergent ·Volcanoes as magma collects in magma chamber,
and as pressure builds up it rises through cracks in
crust and eventually erupts…read more

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On a minor fault (Nojima) Philippines plate Ground moved 05:46 on 17th Lasted 20 seconds
above a destructive plate (oceanic) is subducted 18cm horizontally January 1995
Focus near
margin by Eurasian and 12cm vertically
Causes (continental) The facts to surface
7.2 on Richter scale Death toll 5,500,
Volcanic activity has Japan at risk of epicentre
injuries 40,000, near Kobe
created Japan
Nearly 200000
earthquakes Kobe Earthquake houses totally
destroyed 180,000
buildings 1km stretch of Hanshin Kobe's infrastructure
Expressway collapsed Area worst affected by fire cleared of
collapsed fully operational by July rubble but little rebuilding.
Several trains Most central, commercial
derailed Primary Effects buildings replaced Months Afterwards
Numerous bridges along 120 of 150 quays Year later 80% of port
130km section of Bullet in port of Kobe Railways back in working but Hanshin
Train route collapsed destroyed service by August 1995 Expressway closed
Shortage of Jan. 1999 134,000 housing
Electricity, Roads at gridlock, units constructed, but some Replacement buildings
gas and delaying blankets, clean had to meet stronger
water and food still in temporary
water emergency accommodation earthquake resistance
disrupted services standards
Industries like Panasonic
Secondary Effects forced to close
High rise buildings had
716 aftershocks, Seismic to have flexible steel
Fires due to broken gas frames, smaller
230000 people 74 felt by humans instruments
and electricity raged for buildings concrete
homeless living installed
several days, Kansai International frames and reinforcing
in temporary
destroying 7500 mostly Airport and Akashi bars,
shelters with
wooden houses. At one bridge with high tech
point the wall of fire earthquake proof Buildings on solid Not built with brick or
temperatures at
extended for over 400 construction survived rock, not clay wood
metres…read more

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Collision boundary Eurasian and Iranian Took three days for news of the event to reach the capital Kabul
Plate (both continental)
6.1 on Richter scale 4th February 1998
Causes The Facts
Forced up to form high Movement of Iranian Remote northern Afghanistan province of Takhar
fold mountains (Hindu plate cause frequent
Kush, western part of earthquakes Death toll of around 4000, 10 000 27 villages destroyed
Himalayas go 7600m in injuries, 15 000 homeless
east Afghanistan)
Afghanistan Earthquake
Events Why couldn't Afghanistan cope?
8th Feb- relief team arrived, after long
journey by donkey and horse due to In 1991 UN introduced human development index to measure
rough mountain tracks, landslides, and qualities of life. Afghanistan rated 171 out of 173 countries, one
snow higher than in 1993. Since then drought, civil war and
9th Feb- still no food or medical supplies earthquakes have made it unranked due to lack of info
due to bad weather, blocked mountain
tracks and war with the Taliban Doesn't have technology
to predict earthquakes
10th Feb- Relief agencies flights still held No money for trained and available
up. Survivors living without shelter in emergency services e.g. lack of
sub zero conditions, facing starvation. Poorly built houses, helicopters, ambulances, hospital space
Hundreds of villagers leaving. even in capital and fire engines
16th Feb- Helicopters finally dropped
supplies to 3 isolated villages. So for
488 blankets, 220 tents, 800 quilts, Many remote areas without Mountainous terrain and
1500 tonnes of food and 1.7 tonnes of telephones or electricity severe climate (long, cold
medical kits hindering communication snowy winters) disrupt
transport and aid…read more

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On a plate Dormant since Erupted at 08:32 on 18th May 1980 Erupted at 08:32 on
boundary between 1840's and 50's 18th May 1980
the Juan de Fuca 18th May 1980 largest The largest
Causes earthquake yet (5.1 on Richter landslide ever The Facts
scale) shook free the bulge recorded, moving
15th March 1980 small
earthquakes as magma rose which slid down the mountain at 100mph 57 people died, mostly
from poisonous gases
April and May bulge appeared The cryptodome was exposed,
on north side and quickly grew pressure was released and lava Heard 700
burst out the side of the mountain miles away
370miles2 (lateral blast)
Lateral blast killed
destroyed everything in 17mile Lava flows sucks in air, heats it, air
radius expands and rises, so it gains momentum
Mount St. Helens
Ash fell up to 930 reduced in size by at
miles away least 1300 metres
Mount St. Helens
Effects Ash in the air made it dark at
midday in surrounding area
10's millions trees flattened- Tourism increased as people
livelihood of loggers lost came to see destruction and new
Barges transport on coverage
Columbia river ruined
by sediment
Lava filled Spirit Lake
Flooding from blocked rivers Volcano more
Crops destroyed destroyed roads and railway carefully monitored
Soil fertility improved
by ash…read more

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Indonesia part of island Destructive Plate margin- Considered sacred and has killed people ten times since
arc consisting of over Indian Plate (oceanic) and 1920
13000 islands Eurasian (continental) Facts Destroyed several villages
Causes Turgo, 6km away was worst hit
and killed over 60 people
Indonesia has third (130) of world's most active
volcanoes- 34 on Java, including Merapi
(mountain of fire) which is the most active Merapi Volcano
Sudden and violent, before Ash collapsed houses
November 1994 Eruption
everyone escaped the area and burnt exposed
was covered in red-hot ash, See risk as worth taking Fertile soil- mineral rich
making it dark, so no one so high crop yield
could see
Survivors fled to
Why People live there
Lahars (mudflows) caused by emergency shelters,
Hot wet climate allows High pop. density and
heavy monsoon rains picking up provided in case of
three crops a year farmland shortage, so
ash and loose volcanic material. such events
farmers have to return
Prediction-monitoring future eruptions Protection-
·Activity monitored with simple seismometers e.g. kerosene smoke mudflow dams Responses
covers paper with carbon. Roll of paper turned by car battery under ·Over 70 dams built
needle, which jumps if earth moves in valleys to trap
·Data from stations is collected mud from lahars, Evacuation
·Every month summit is visited to check changes in pressure and which is later ·Some local people
temp. spread over fields, specially trained to
Resettlement and water slowly give emergency
·Settlement is not allowed right by summit, but farming is released treatment and
·Villagers evacuated for prohibited area or summit have option of- organise transport
to evacuation
·Living in relocation settlements in safer concrete houses with electricity camps and
·Moving (arranged by government) to less crowded islands like Sumatra temporary
·Few people elect to move and return to villages despite risk accommodation…read more

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