Presentation on theme: "Restless Earth Revision Revise the topic Practice exam technique"— Presentation transcript:
1 Restless Earth Revision Revise the topic Practice exam technique
2 Practice drawing these diagrams. Get into groups of four and number yourselves.Draw your plate boundary:1. destructive2. collision3. constructive4. conservative2 minutesPractice drawing these diagrams.Use them in the exam.
3 Diagrams Four plate boundaries Convection currents Shield and composite/strato- volcanoesStructure of Earth (probably won’t be asked to draw this one; need to be able to interpret it)
4 Review and Rate Read the summary of the topic. Rate each section: how confident do you feel with each part?
5 The Earth’s StructureEarth’s interior has a layered structure, with different composition and physical properties.Interpreting a cross-section of the Earth, with details (temperature, density, composition, physical state) of layered structure (including the asthenosphere)
6 Different types of crust. Contrast continental and oceanic crust.CONTINENTALOCEANICThis is heavy (density of 3.0), made ofMinerals rich in Iron and MagnesiumIs about 6-10 km thick on average and isusually under 200 million years old.This is lighter (density of 2.6), made ofminerals rich in silica and aluminium,is about 30-70km thick and is mainlyover 1500 million years old.
7 Convection cell in the mantle Convection CurrentsSolidCrustConvection cell in the mantlePlumes of heat rise in the mantleConvection in the liquid outer core
8 Earth’s Tectonic Plates and their Boundaries Mapping the distribution of the three plate margin types, and naming major plates.
10 Types of Volcano A shield volcano e.g. Mauna Loa, Hawaii Very hot, runny, basaltic lava.Eruptions rarely violent.A composite or stratovolcanoe.g. Mount Pinatubo, PhilippinesThick, viscous, andesitic lava.Explosive eruptions.
12 Contrasting earthquake effects in named locations Impacts on property versus people. Loma Prieta earthquake, USADate: Tuesday 17 October 1989, at 17.04Magnitude: 6.9 on the Richter ScaleEpicentre: in a mountainous part of Santa Cruz County, 90 km south-east of San FranciscoDeath toll: 63Injured: 3,757Homeless: 12,000Property cost: $10 billionKashmir, PakistanDate: Saturday 8 October 2005Magnitude: 7.6 on the Richter ScaleEpicentre: Muzaffarabad, the capital of Pakistani-administered KashmirDeath toll: 75,000Injured: 75,000Homeless: 2.8 millionProperty cost: $440 millionImpacts worst on propertyin developed countries.Impacts worst on peoplein developing countries.
13 Contrasting economic and social volcanic hazard impacts Mount St Helens, USADate: Sunday 18th May 1980 at 8.33 am.Magnitude: 5 on the Volcanic Explosivity Index 5 (paroxysmal).Homes destroyed: 200Death toll: 61 (most as a result of poisonous gases which accompanied the blast).Evacuated: 2,000 peopleProperty cost: $1.1 billion.Mount Nyiragongo, DR CongoDate: 17th January 2002.Magnitude: Gentle; 1 on the Volcanic Explosivity Index (VEI).Homes destroyed: 12,500Death toll: 100 (mostly from poisonous gas and getting trapped in lava).Evacuated: 400,000Lava: hot, runny, basalticHomeless: 120,000Economic impacts worsein developed countries.Social impacts worsein developing countries.
14 Predicting Earthquakes Earthquakes are not as easy to predict as volcanic eruptions. However, there are still some ways of monitoring the chances of an earthquake:Laser beams can be used to detect plate movement.A seismometer is used to pick up the vibrations in the Earth's crust. An increase in vibrations may indicate a possible earthquake.Radon gas escapes from cracks in the Earth's crust. Levels of radon gas can be monitored - a sudden increase may suggest an earthquake.
15 Preparing for Earthquakes People living in earthquake zones need to know what they should do in the event of a quake. Training people my involve holding earthquake drills and educating people via TV or radio.People may put together emergency kits and store them in their homes. An emergency kit may include first-aid items, blankets and tinned food.Earthquake proof buildings have been constructed in many major cities, eg The Transamerica Pyramid in San Francisco. Buildings such as this are designed to absorb the energy of an earthquake and to withstand the movement of the Earth.Roads and bridges can also be designed to withstand the power of earthquakes.
16 Earthquake-proof building design Developed countryDeveloping country
17 Predicting Volcanic Eruptions Warning signsMonitoring techniquesHundreds of small earthquakes are caused as magma rises up through cracks in the Earth's crust.Seismometers are used to detect earthquakes.Temperatures around the volcano rise as activity increases.Thermal imaging techniques and satellite cameras can be used to detect heat around a volcano.When a volcano is close to erupting it starts to release gases. The higher the sulfur content of these gases, the closer the volcano is to erupting.Gas samples may be taken and chemical sensors used to measure sulphur levels.
18 Predicting and Preparing for Volcanic Eruptions
19 Preparing for Volcanic Eruptions Creating an exclusion zone around the volcano.Being ready and able to evacuate residents.Having an emergency supply of basic provisions, such as food.Funds need to be available to deal with the emergency and a good communication system needs to be in place.
20 Haiti, 2010 Impacts Response Problems Death toll: 200,000 (estimated) Homeless: 1.5 million (estimated)Tens of thousands without food, water and medical suppliesPort-au-Prince port badly damagedUS took control of Port-au-Prince airportUN World Food Programme increased food aid to survivors, e.g. 2 million meals delivered on one dayUS carried out air dropsThe Haitian authorities were not prepared for the earthquakePort-au-Prince airport has limited capacityLack of fuel
21 Glossary You need to be familiar with these words so that you can: understand what questions mean (easier)define them (harder)Use the glossary sheet as a check list. Tick them off once when you when you understand them and again when you can define them.Concentrate at first on the terms in bold.
23 (a) Identify one advantage and one disadvantage that Sakurajima has brought to Japan. (2)
24 (b) Explain one reason way in which the impact of a volcanic eruption might be different in a less developed country. (2)More deaths/greater impacts on people. Accept other reasonable suggestions.Explanation:People more likely to live in risky locationsCan’t afford safe, well-built houses so buildings often collapseCommunications poor, so warning and evacuation may not happen (so effectively)PovertySlow/inadequate relief effort may lead to lack of shelter, clean water and food. Disease may spreadGovernments don’t have the money or resources to provide aid
25 (c) Using examples, explain how eruptions can be predicted. (4)
26 (c) Using examples, explain how eruptions can be predicted. (4) Warning signsMonitoring techniquesHundreds of small earthquakes are caused as magma rises up through cracks in the Earth's crust.Seismometers are used to detect earthquakes.Temperatures around the volcano rise as activity increases.Thermal imaging techniques and satellite cameras can be used to detect heat around a volcano.When a volcano is close to erupting it starts to release gases. The higher the sulfur content of these gases, the closer the volcano is to erupting.Gas samples may be taken and chemical sensors used to measure sulphur levels.