Flashcards
The restless earth (Geography)
Cards in this deck (42)
- 1Distribution of plates
- 2continental crustolder- most over 1500 million year old
less dense
cannot sink
cannot be renewed or destroyed - 3Oceanic crustNewer - most less than 200 million years old
denser
can sink
can be renewed and destroyed - 4Constructive plateWhen plates move apart a constructive plate boundary results. this usually happens in the ocean. As the plates pull away from each other, cracks and fractures form between the plates where there is no solid crust. Magma forces it way into the cracks and makes its way to the surface to form volcanoes in this way new land is formed as the plates gradually pull apart
- 5Conservative plate marginsconservative plate margins (here the plates slide past each other) they move in similar direction (not the same) at different angles and speed. one is moving faster than the other and in a sightly different they tend to get stuck.the build up of the pressure causes them to be released.the sudden release of pressure causes an earthquake, crust is being neither made or destroyed.
- 6Destructive PlateConvection currents in the mantle cause and the plates to move together. the oceanic plate (denser) sink under the lighter continental plate know as subduction. pressure is created and the oceanic crust melts to form magma
- 7composite volcanoesAcidic lava
Alternate layer of rocks
Sticky lava
Lots of steam
Steep sided cones - 8Shield volcanoesAsh cloud
Hotspots
Runny lava
Basic lava
Wide cones - 9Shape of a supervolcanoA mega eruption where at least 1000 cubic km of material is erupted. Not classic volcano shape – tend to be sunken surrounded by area of higher land. Flat areas. May indicate size/ shape by contrasting with a volcano.
- 10Formation of a supervolcano1 destructive plate margin or on a 'hot spot' rises up through the cracks
2 because the layer of the crust is to thick the magma does not escape.
3 magma spread
4 the magma chamber collapses forming a depression called a caldera - 11how does supervolcano effect peopleEconomically: crushed buildings, infrastructure and crops being destroyed
Environmentally: reduce sunlight, trigger rainfall causing mudslides known as lavars, dirty water, climate changes in countries and volcanoes can inject sulfur gas into the upper atmosphere.
Social: kill and sicken humans and animals, houses broken, crops killed and vegetables, contaminated water and ash kills - 12Volcanoes case study: chances peak (Montserrat)the north american plate is being subducted under the Caribbean plate.
It was a composite volcano.
There were ash clouds, pyroclastic flows.
It erupted in June 1997.
people were evacuated on the august 1995
19 people died
66% of all houses were destroyed, 77% of the infrastructure was destroyed
population now is 8,000 (older people) - 13Fold MountainYoung fold mountains include ranges such ah Himalayas, Rockies, alps, Andes. older ranges of fold mountains that are used high due too erosion include the Cambrain mountain and Cumbrian mountain in the UK.
- 14Fold mountains 21) fold mountains are formed by all destructive plate margins.
2) At a zone of subduction the mountain are created when the lighter continental crust is pushed upwards.
3) Two continental crust meet and collide which formed the fold mountains.
4) Young fold mountains (those that have been formed in the last years) are the highest areas in the world. - 15ocean trenches1) Ocean trenches are formed by all destructive plate margins that collide.
2) ocean trenches form some of the deepest parts of the ocean at a zone of subduction the trenches are created when the continental crust goes on top of the oceanic crust - 16monitoring and predicting volconoesGlobal positioning system (GPS) use satellites to detect movement of as little as 1 cm - use satellites to detect minute movement.
Digital cameras placed on the him of craters can photograph events relatively safely.
The change in the temperature at the surface can be seen on satellite images.
Gases being emitted from the vent change before the eruption - there is an increasing amount of suphur dioxide.
Robots called 'spiders' are often to monitor changes. - 17Earthquake: sudden and brief period of intense ground shakingDestructive plate margins: pressure resulting from the subducting plate and its subsequent melting can trigger strong earthquake as this pressure is periodically released.
Conservative plate margins: earthquake tend to be of greater strength. plates slide past each other the plates tend to stick for periods of time. this causes stresses and pressure to build. the release of the pressure occurs in a sudden, quick release of the plates and the result is an earthquake.
Constructive plate margins: earthquake tend to be use severe than those at destructive or conservative plate margins. the friction and pressure caused by the plates moving a part is less intense then at destructive plate margins. - 18kobe earthquake 1Plate margin: destructive at a zone of collision
When: 5:46 am on 17 January 1995
Cause: the Philippines plate shifted uneasily beneath the Eurasian plate along nojima fault line that runs beneath kobe. the earthquake measured 7.2 on the richer scale with tremors lasting 20 seconds - 19kobe: primary effects6,434 people were killed
40,000 people were injured
Gas mains ruptured
Water pipes fractured
Sections of elevated road collapsed
2 million homes without electricity and one million had to cope without water for 10 days - 20KOBE: Secondary effectsFires engulfed parts of the city - specially the west of the port
Damages to road and water supply made attempts to extinguish them imposed.
people huddled in blankets on the streets and in tented shelters in the park in fear of returning to buildings damaged by the earthquake .
the damage caused was excess 220 billion pounds and the economy suffered.
companies such as Panasonic had to close temporary. - 21kobe respondsfriend and neighbours searched though the rubble for survivors.
hospitals struggled to cope with the injured, treating people and operating in corridors.
majors retailers such as 7-11 helped provide essentials and Motorola maintained phone charges - free charge - 22sichuanwhen:12 may 2008 2:28 pm
located: china
Cause: Indian plate colliding with the Eurasian plate pressure was released along the Longmenshan fault line that runs beneath Sichuan. this led to an earthquake measuring 7.9 on the richer scale with tremors lasting 120 seconds. - 23sichuan : primary effectsthe first death toll was 8,700
80% of the buildings collapsed about 5 million buildings collapsed.
A school collapsed which killed 900 pupils/ parents angry - cheap building material used.
communications were stopped neither land nor mobile phone worked. - 24sichuan: secondary effectsdeath troll rose from 8,700 to 55,000 to 69,000.
18,000 were rising
5 million (some say 11) homeless
roads were blocked by landslides and some landslides also blocked rivers, leading fears of flooding.
the cost was predicted to be $75 million - 25Sichuan earthquake responses20 helicopters were assigned to rescue.
thousands of army troops were deployed.
immediate needs were clean water, food supplies and tents to shelter people from the spring rains.
Teams from Japan, Russia and South Korea joined the joined the rescue effort.
Donations to the Red cross exceeded 100 million pounds in the fortnight after the earthquake.
medicine and doctors were available.
one million temporary small houses will be built house those made homeless. - 26mercalli scaleused after the earthquake
visual use picture/ images
description of damage
1-12 - scale in I to XII
example - III - slightly felt indoors as through a large truck were passing
subjective - 27richer scaleLogarithmic scale - increases by 10 so 2 is 10 times more powerful then 1 , 3 is 100 times more powerful than 1.
Based on scientific recordings of the Amount of movement
No upper limit to this scale
objective - 28the three P'sPrediction
protection
preparation - 29predictionattempts to forecast an aren't - where and when it will happen - based on current knowledge
- 30protectionconstructing buildings so that they are safe to live in and will not collapse
building to an appropriate standard and using designs to withstand movement is the main way of ensuring protection. - 31preparationorganising activities and drills so that people know what to do in the event of an earthquake.
involves hospitals, emergency services and inhabitants practicing for major disasters.
including having drills in public building and code of practice so that people know what to do to reduce the impact and increase their chance of survival. - 32earthquake proof building:
- 33AndesAre fold mountains dominate the western coast of southern America.
- 34Andes AgricultureFraming on steep slops at high altitudes takes a lot of planning and inventive thinking
Farmers - terraces - steps cut in the hillside to create flat land
Flat land retains water and prevents soil movement
Female llamas used for meant, milk and wool to make rugs - 35Andes tourismthere are many natural attractions i the Andes such as mountain peaks, volcanoes, glaciers and lakes. some tourist attractions show how people settled in these inhospitable areas.w
- 36Andes hydroelectric powersthe steep slopes and narrow valleys that limit farming are an advantage for hydroelectric power (HEP). they can be more easily dammed than wider valleys and relief encourages the rapid fall (flow) of water needed to ensue the generation of electricity. the melting snow in spring increase the supply pf water.
- 37Andes miningthe Andes had a range of important minerals and the Andean countries rank in the top 10 for tin, nickel, silver and gold. more than half of Peru's exports are from mining.
This brings with in alternative sources of jobs. However, this growth also bring many problems, including lack of services and an increased crime rate. - 38Tsunami Indian oceandate: 26 December 2004
Cause: results of the indo - Australian plate subducting the Eurasian plate. the earthquake measured 9.1 on the Richer scale according to the US Geological survey, but others have estimated in at 9.3. - 39Tsunami primary effectsThe highest wave to come ashore was 25cm. It was estimated that more than 220,000 people had died and 650,000 were seriously injured. many public buildings including schools and hospitals were wiped out in some areas.
- 40Tsunami Secondary effectsUp to 2 million people were made homeless. Many people posted photos of loved ones in hope that they had survived. Treating the injured must have been hard as public buildings such as hospitals were wiped out in some areas. Identifications of the dead on such a massive scale was a real issue. Some 1,500 settlement are believed to have been wiped out completely in Banda Aceh, the scene was of widespread devastation.
- 41Tsunami short term responsesRescue services and emergency teams were swamped by the scale of the disaster. Injured people were untreated for days as wounds gangrenous and conditions worsened. Bodies littered the streets before being buried in mass graves.
There was an immediate response from the international community. Fresh water, water purification tablets, food, sheeting and tents all poured in as aid. Medical teams and forensic scientists arrived. The UK government promised 75 million pounds and public donations of 100 million followed. - 42Tsunami long term responsesA year later 372 million pound had been donated by the British public, but on 128 million pounds had been spent be the Disasters Emergency Committee (DEC). There were organisational issues following the collection of such large sums of money. Rebuilding was progressing and DEC has spent 40 million pounds on projects in Sri Lanka and Indonesia. there were plan to spend a further 190 million pounds in the seconds year building 20,000 houses for 100,00 0 homeless people. there was till concerns about the numbers still homeless one year on.
Before the tsunami there had been no early - warning systems in the Indian ocean. The Indian ocean tsunami warning system was set up in June 2006.
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