Unit 1 Dynamic Planet Topic 1 Restless earth

Transcription

1 Unit 1 Dynamic Planet Topic 1 Restless earth Instructions Complete this revision sheet using your exercise book and text book. Store this revision sheet in your revision folder once it has been checked by your teacher. Fill in the sheet in as much detail as possible to help you when you revise for your GCSE exams. If you would like to achieve a grade B this sheet needs to be completed to that level. Write neatly so that is easy to read when you revise. There is a completed copy of this sheet in the ilab if you would like to check your work. Ask at the counter for the geography revision folder, it is only available for reference work in the library not to take home. 1. The Structure of the earth. Label the diagram below (page 8) 2. Define the following words. (Page 8/Glossary) A. Lithosphere = It is the uppermost layer of the earth. It is cool and brittle. It includes the very top of the mantle and above is the crust B. Asthenosphere = Part of the earth s mantle. It is hot semi-molten layer that lies beneath the tectonic s, it is between 20 and 70 km thick. 3. Complete the table below to show the details of each layer. (page 9) Layer Sub Layer Density (grams/ cm3) Physical state Composition Temperature (ºC) Lithosphere Continental crust 2.7 Solid Granite 900 Oceanic crust 3.3 Solid Basalt 900 Mantle Asthenosphere Partially molten Peridotite Lower mantle Solid Peridotite Core Outer Core Liquid Iron and nickel

2 4. Use the diagram below to explain why the earths tectonic s move (page 10 and 11) The inner core is so deep and is under such huge pressure that it stays solid. The outer core is liquid because it is under lower pressure. As heat rises from the core it creates convection currents in the liquid outer core and mantle. These vast mantle convection currents are strong enough to move the tectonic s on the earths surface. The convection currents move as fast as you finger nails grow. Radioactivity in the core and the mantle is the engine of tectonics. The inner core is so deep and is under such huge pressure that it stays solid. The outer core is liquid because it is under lower pressure. As heat rises from the core, it creates convection currents in the liquid outer core and mantle. (see diagram) These vast mantle convection currents are strong enough to move tectonic s on the Earths surface. This in turn causes different tectonic hazards. The convection currents move about as fast as your fingernails grow. Radioactivity in the core and mantle is the engine of tectonics. 5. Label the map below to identify the major tectonic s (page 13)

3 6. Complete the table below to show the type of volcanic and earthquake hazards found at each. (page 14 and 15) Plate Example Earthquakes Volcanoes Diagram 1. Conservative. San Andras fault in California, USA, north American and Pacific s sliding past each other. -Destructive earthquakes up to a magnitude of 8.5. Small earth tremors almost daily. No volcanoes 2. Constructive Iceland on the mid-atlantic ridge. The Eurasian (continental) and North American (oceanic) s pulling apart 3. Destructive Andes mountains in Peru and Chile. Nazca oceanic is subducted under the South American Continental. 4. Collision Himilayan mountains (fold mountains) Formed as the Indian and Eurasian (continental s) push into each other. -Small earthquakes up to on the richter scale -Very destructive up to a magnitude of 9.5 on the richter scale. -Destructive earthquakes up to a magnitude of 9.0 -Landlsides are triggered. -Not very explosive or dangerous. -occurs in fissures (cracks in the crust ) -Erupt basalt lava at 1200 degrees. Basalt lava is very runny creating shield volcanoes. -Very explosive (including water and steam) and destructive volcanoes. -steep sided cone shaped created by thick/viscous lava. -Lava at degrees -Volcanoes are very rare 7. Montserrat an example of a Volcanic hazard. Name of Volcano : Chances Peak Date of eruption :1996 to present Location : Montserrat, Caribbean Type of volcano : Destructive Type of Lava : Granite Name of tectonic s : The Caribbean (oceanic) is being subducted below the North American (continental) Type of : Destructive

4 8. Type of volcanic hazards (e.g. Lava, Pyroclastic flows) Pyroclastic flow which is hot fragment of rock, ashes and lava particles. 800 degrees. Lava, ash clouds covering the skies. Rock fragments. Pumice stones. 9. Impacts of Montserrat eruption Primary Secondary Economic Social Environmental Half of the fertile land was burned and destroyed -Impact of lava on people -Impact on people s poverty -21 people died - Inhalation of dust and ash causes respiratory (breathing) illnesses. -Pyroclastic flow clouds and its effects on people and property. -forests burned - large areas of land covered in lava flows, ash and dust = destruction of habitats. -Disruption to infrastructure/airport closed -Disruption to employment (capital city destroyed) -Decline in income -Decline in agricultural output used to export food. -Port closed so export and import prevented -Capital city Plymouth totally destroyed along with hospital, schools, government building etc. -Income from volcano tourism -Disruption to travel -Homelessness (people had to live in temporary accommodation in the north or emigrate to Antigua/UK) -Fire outbreaks -Danger zones people were not allowed to work on their farms -3/4 country was uninhabitable -Forest took a long time to recover. -Beautiful Caribbean landscape damaged/ impacts on tourism industry? 10. Risk reduction in Montserrat (describe how they reduce the risk of the volcano under the headings below) (page 17 and your exercise book) A. Prediction. There were natural warning signs that it was going to erupt Some preliminary earthquakes were recorded for 2-3 years before the 1st eruption Initial steam and ash from chances peak 1 month before the big eruption The Montserrat volcano observatory (MVO) now monitors the volcano regularly using modern high tech equipment. B. Warning Radio warnings given on Radio Montserrat for example to stay under a heavy roof or wear a mask if a heavy ash fall is predicted. Visual signs from the volcano for example smoke and steam. The MVO issue warnings online. C. Evacuation The UK government offered 2500 to help people emigrate and start a new life in a safe country Church and other public buildings set up as a shelters for homeless Conditions for evacuees were cramped, 12 people sharing 1 room, 33 people sharing 2 toilets Residents of the capital Plymouth were evacuated to the safety of the north.

5 11. Evaluate the immediate response and relief efforts in Montserrat. A. Immediate response (i) The Relief efforts to the eruption of chances peak was to.. Warn people Help people evacuate to the North Provide temporary accommodation in public buildings People were given vouchers to buy food as their farm land had been destroyed. The UK provided financial support as Montserrat is an ex UK colony. (ii) The Relief efforts was poor/good/very good because. Good because only 21 people died which is very low for such a large eruption in a LEDC. However people were housed in very overcrowded conditions. Imported food was very expensive. But no diseases broke out due to unsanitary conditions. B. Immediate response (i) The relief efforts after the volcanic eruption included Actions taking by the people and government as the disaster was happening see above. (ii) The Immediate response were poor/good/very good because.. See above 12. annotate the 2 diagrams below to show how the buildings are designed to withstand an earthquake. (page 21 and 23) LEDC Earthquake proof Building MEDC Earthquake proof building

6 13. Complete the table below to compare the tectonic hazards you have studied Summary of Tectonic Hazards Example Location Type of Hazard Level of development Magnitude/ Type of eruption Death toll Homeless Economic impact/ Cost Other /Notes Montserrat Caribb ean Island Volcano LEDC Destructive Very powerful volcano (VEI 4 = large) 21 (19 primary/2 after) More than people left Haiti 2010 Kobe January 1995 Japan Tsunami Haiti, Caribbean Earthquake LEDC 7.0 Focus = 13km deep Epicenter 25km from Port au Prince (capital = pop 2.5 million) Japan EQ MEDC 7.2 Focus = 16km Epicenter 20km Kobe (pop 1.5 million) Soft ground made the shaking worse injured 5000 Dead injured (v. high pop density and people still in bed when it struck at 5.46am) 1 million poorly built houses Japan Tsunami MEDC , ,000 evacuated because of lots of homes The port, communication links and major roads were destroyed. Rubble from buildings blocked roads. -clothing factories closed/ damaged. They provided 60% of exports. -1/5 jobs lost. 250, billion damage caused to roads, houses, factories and infrastructure (gas, electric, water and sewage pipes) Bridges and roads, train lines were damaged disrupting transport and communication links. billions Secondary = Cholera outbreak killed year later 1 million still displaced and living in refugee camps 190,000 building Fires broke out = secondary cause of death Businesses effected/ port closed Homelessness/ disrupted schooling, unemployment, stress.

7 Summary of Tectonic Hazards Example Location Type of Hazard Level of development Magnitude/ Type of eruption Death toll Homeless Economic impact/ Cost Other/ Notes Montserrat 1995 onwards Caribbean Volcano LEDC GNP = V. High V. Explosive Destructive Atlantic subducted below Caribbean Pyroclastric Flows 21-V. low. put in exclusion zones to reduce death toll. Warning (e.g. steam and ash) People forced to live in overcrowded north e.g. 33 people living in a church sharing showers Plymouth Capital city destroyed (port/ hospital/ industry) 2/3 of island uninhabitable Sakurajima 1950 onwards Sichuan 12 May 2008 East coast of Japan Province in central China Volcano MEDC GNP= V. Explosive Composite cone volcano Erupts 200x a year Destructive Pacific subducted below Eurasian EQ LEDC/FCC GNP = 6 Richter scale 200 aftershocks Collision Eurasian and Indian Plate - - Positive = Tourist attraction/ hot springs/ volcano tourism Negative= Potential cost of eruption Cost of manage- ment- Damage to property Dead injured 5 Million $75 Billion 700 Schools 80% of buildings in Wenchuan V. mountainous/ Heavy rain/ landslides effected rescue efforts/ soldiers = rescue effort Aid UK = $2 Million China $1.5 Billion San Francisco/ Loma Prieta October 17 th o clock California San Francisco and Oakland EQ MEDC 6.9 Richter Scale 15 seconds Conservative Pacific and North American 67 Dead 600 homes damaged/ destroyed 2000 homeless $4.4 Billion