Tectonics case studies

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  • Created by: 13cr240
  • Created on: 07-08-19 18:54

Describe Philippines as a multiple hazard zone

  • Sitsss on a convergent plate boundary so volcanoes and earthquakes 
  • North and east coast face the Pacific ocean which is worlds most tsunami prone zone 
  • Lies in south east Asian typhoon belt with around 15/ year 
  • Steep topography with high deforestation and high rainfall means landslides are common
  • It has 47 volcanoes 
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Facts about Philippines

  • 25% of population live in poverty
  • 22 volcanic eruptions since 1960 
  • 22% of its volcanoes are active 
  • Rapid urbanisation 
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Give an example of a shield and composite volcano

Shield volcano: 

  • Mount Kilauea on Hawaii on constructive plate boundaries

Composite volcanoes:

  • Mount Fuji in Japan they are at destructive plate boundaries above 8000ft 
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Where is the deepest place on Earth

"Challenger deep" which is 11km deep 

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Give example of.......

Oceanic meets continetal margin: 

  • Andes mountains between Nazca and south america 

Rift valley:

  • The east African rift valley 

Conservative plate boundary:

  • San andreas fault between North america and pacific plate 
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Give example of.......

Contintal meets continetal:

  • Himilyan mountains

Mid- ocean ridges:

  •  Mid atlantic ridge 

Intraplate location:

  • Yellow stone national park 
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List some tectonically safe and unsafe regions.

Safe regions:

  • Australia 
  • UK
  • North/central Africa 
  • Central russia

Unsafe regions:

  • South america 
  • Japan 
  • Philippenes
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Describe the Hawaii hotspot

It extends over 5000km along emperor seamount chain from Kauai to hawaii and it is an island arc in the pacific ocean connected to no plate boundary. 

They are located as a concentraion of radioactive elements inthe matle eat at plate above creating a stationary hotspot which plate moves over creating volcanoes which eventually collapse into sea mounts.  

4 of the volcanoes are active and more than 123 are extinct 

Just under 2000 miles from nearest plate boundary

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Thickness of oceanic and continental shelf and tem

Oceanic crust is 6-10km thick 

Continental crust is 45-50km thick 

Temperatures of 6000 degrees 

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Impacts of Japans tsunami

  • Fukishema nuclear power plant posed a threat from flooding as the nuclear core needed time to cool 
  • Susidence of the coast caused it to sinkby 1m so more flooding and it meant flood defences werent as successful
  • Overnight fires from gas, oil, electricty, leaks
  • Impacted more countries than Japan with 230'000 deaths in 12 countries. 
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Describe the Japan Tsunami

  • Happened on 11/3/11 
  • 9.0 magnitude 
  • 22'000 deaths 
  • Quake was 6km underwater 
  • Caused by Pacific plate under Eurasion 
  • Earthquake lasted 5 minutes 
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Reasons why Japan earthquake was not a major disas

  • Automatic warning system within seconds of the P-waves arriving
  • earthquake proof buildings 
  • Education schemes in schools 
  • Flood defences eg 10m wall built along the coast 
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Impacts of South East Asian tsunami

  • 5 million affected 
  • 1.7 million homeless. 
  • 20 islands in the maldives were totally destroyed 
  • in some villages 70% of people were killed 
  • Andaman and Nicobar islands were cut off as jetties linking islands were washed away 
  • Economies devasted espeically fishing, tourism and agriculture 
  • In Sri Lanka 60% of fishing fleet destroyed 
  • Ecosystems eg Coral reefs destroyed 
  • Fresh water supplies. and soil contammination by seawater 
  • Economic cost of 10billion 
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Reasons why the south East Asian tsunami was major

  • Epicentre close to coastal villages who had no warning/time to react
  • No education on tsunami warning signs 
  • No early warning systems 
  • Tsunami retreated inland for many miles as low altitidue 
  • Mangroove forests had been removed 
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Describe the south East Asian tsunami

  • Boxing day 2004 
  • 290'000 dead/missing 
  • 9.0 magnitude 
  • 15 minutes from hypocentre waves were 17mhigh 
  • reached 3km inland in India 
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Impacts of Eyjajalljakull

  • 100'000 commercial flights cancelled and 10 milion were stranded as ash threatened to clog airoplane engines 
  • Areas flooded as volcano melted glaciers above volcano 
  • Agricultural land damaged by heavy ash fall. 
  • People asked to remain in doors 
  • Airlines across the world were hindered from flying so they lost 1.7billion revenue 
  • Kenya lost up to 3million per day as EU flights were cancelled which 20% of its economy relies on exproting vegtables and flowers 
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Describe Eyjafjallaajokull

  • March 2010 
  • 500m fissure opened up 
  • Ash flume rose to around 9km 
  • 4 on volcanic explosivity index 
  • Happened under an icesheet 
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Impacts of Nyriagongo

  • Destroyed 1/3 of Gorma city
  • 350'000 people fled
  • 14 villages destroyed 
  • Larva covered airport and cut off roads 
  • Lava took a long time to cool 
  • Cholera spread due to a lack of sanitation
  • Business and jobs suffered 
  • Aviation fuel stores exploding killing 50 people 
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Reason why Nyriagongo was a major disaster

  • Unrest in congo meant it was difficult to monitor volcano and put repsonses in place 
  • Many people live near volcano and there is no exclusion zone as many people work on rich volcanic soil for agriculture 
  • Lack of sanitation meant cholera spread 
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Facts about Nyriagongo

  • January 2002 
  • Most volumous lava lake in the world 
  • Divergent plate boundary at East african rift valley
  • 3 streams of lava drained side
  • Reached speeds of 60km/h 
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Reasons why Lomo pieta was not a major disaster

  • Hit when baseball was on so freeway was less conjested so reduced death 
  • Many homes were unaffected as they were bolted to foundations
  • 12000 people had power restored in 2 days 
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Impacts of Lomo prieta

  • Land was manmade landfill of soft, sandy soil which amplified the ground shaking so lots of damage 
  • Soil liquified causing buildings to collapse 
  • The Cypress freeway collapsed causing 42 deaths on lower level 
  • 4000 landlsides. 
  • 12000 homes damaged 
  • $6 billion property damage 
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Describe Lomo Prieta.

  • October 1989 
  • 6.9 magnitude. 
  • Near san fransisco on san andreas fault 
  • 62 deaths 
  • 15 seconds of shaking 
  • Broadcast when world series of baseball was on 
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Describe the Nepal earthquake

  • At midday so most people were working in the fields so fewer deaths 
  • Most of nepal has low population density. and it happened in rural areas
  • 7.8 magnitude 
  • April. 2015 
  • Between indian and eurasian plate boundary 
  • 9000 killed 
  • 3 million homeless 
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Impacts of Nepal earthquake

  • One of worlds poorest countries 197/229th on the GDP per capita
  • Very unprepared with weak infrastructure so lots of building collapse 
  • Many large aftershocks add to destruction 
  • Himilyan aarea. which. is verymountanous so landslides devastating rural areas and leaving places isolated so resuce was difficult 
  • nepals emergancy services were uable to cope so relied on foreign aid 
  • Tourism reduced rapidly
  • Economy expected to have lost $5billion which is 25% of its GDP 
  • 6.6 billion required for rebuild. 
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