Restless Earth Revision Sheet (UNIT 1 topic) Key Idea Content Case Studies The Earth’s crust is unstable, especially at plate margins. Distribution of plates; contrasts between continental and oceanic plates. You can locate and name the main different plate margins on a world map. You can give examples of famous locations such as the San Andreas Fault or where in Iceland you can walk between the Pacific and Eurasian plate (Constructive plate boundary). Destructive, constructive and conservative plate margins. You can use Iceland as an example of a country at a plate boundary and you can describe how it has formed though millions of years of eruptions. Unique landforms occur at plate margins. Location and formation of fold You can name and locate the Andes, The mountains, ocean trenches, composite Alps and the Himalayas. You can locate volcanoes and shield volcanoes. ocean trenches on a world map describe their formation in relation to destructive plate margins. You can give an example of a composite cone (Mt St Helens or Eyjafjallajökull). And a Shield volcano (Kilauea on the island of Hawaii). You can explain what determines the shape Revised /Date of the volcanoes (viscosity of lava). People use these landforms as a resource and adapt to the conditions within them. A case study of one range of fold mountains. The Andes case study. The ways in which they are used – farming, hydroelectric power, mining, tourism and how people adapt to limited communications, steep relief, and poor soils. Link to the Andes case study from textbook. Volcanoes are hazards resulting from tectonic activity. Their primary and secondary effects are positive as well as negative. Responses change in the aftermath of an eruption. Characteristics of different types of volcanoes. Shield and composite cone volcanoes. You can draw and label these from memory. A case study of a volcanic eruption – Mt St Helens case study. its cause; primary and secondary Eyjafjallajökull, Iceland (See new text book). effects; positive and negative impacts; immediate and long-term responses. Monitoring and predicting volcanic eruptions. You know 4 ways we can monitor volcanoes and can comment on their effectiveness, Supervolcanoes are on a much bigger scale than other volcanoes and an eruption would have global consequences. The characteristics of a supervolcano and the likely effects of an eruption. You can explain the formation of a supervolcano and know their features. Earthquakes occur at constructive, destructive and conservative plate margins. Location and cause of earthquakes. Features of earthquakes – epicentre, focus, shock waves and the measurement of earthquakes using the Richter and Mercalli Scales. The effects of earthquakes and responses to them differ due to contrasts in levels of wealth. A case study of an earthquake in a rich part of the world and one from a poorer area – their specific causes; primary and secondary effects; immediate and long-term responses – the need to predict, protect and prepare. Contrasts in effects and responses will be clear. Yellowstone National Park, USA. You know the local, national, international and global impacts of a possible eruption. You are good at describing the location of earthquakes around the world. You can explain the locations of these earthquakes in relation to plate boundaries. Kobe Japan 1995 or Tohoku Japan 2011 (MEDC) and Haiti 2010 (LEDC) detailed case studies. You can describe and explain these case studies giving an explanation for the differences between them referring to wealth. Tsunamis are a specific secondary effect and can have devastating effects in coastal areas. A case study of a tsunami – its cause, effects and responses. Japan 2011 Tsunami. You have a detailed case study on the causes, effects and responses to this tsunami. Restless Earth Key Words Key words Crust Plate Plate margin Mantle Convection currents Oceanic crust Continental crust Destructive plate margin Constructive plate margin Subduction Collision Volcano Conservative plate margin Earthquake Fold mountains Ocean trenches Composite volcano Shield volcano Definitions The outer layer of the earth. A section of the earths crust. The boundary where two plates meet. The dense, mostly solid layer of the earth between the outer core and the crust. The circular currents of heat in the mantle. Newer, denser, cans sink, can be renewed and destroyed. Older, less dense, cannot sink, cannot be renewed or destroyed. A plate margin where two plates are moving towards each other resulting in one plate sinking beneath the other. A plate margin where two plates are moving apart. When oceanic crust sinks under continental crust at a destructive margin When two plates of continental crust meet head on and buckle. An opening in the earth’s crust through which molten lava, ash and gases are ejected. A plate margin where two plates are sliding alongside each other. A sudden and often violent shift in the rocks forming the earths crust, which is felt at the surface. Large mountain ranges where rock layers have been crumpled as they have been forced together. Deep sections of the ocean, usually where an oceanic plate is sinking beneath a continental plate. A steep sided volcano that is made up of a variety of materials such as lava and ash. A broad volcano that is mostly made up of lava. Subsistence farming Terraces Irrigation Hydroelectric power Natural hazard Primary effects Secondary effects Aid Lahar Hazard maps Supervolcano Caldera Geothermal Geyser Hot spot Focus Richter scale Epicentre Farming to provide food and other resources for the famers own family. Steps cut into hillsides to create areas of flat land more suitable for growing crops and for machinery. Artificial watering of the land. To use of flowing water to turn turbines to generate electricity. An event over which people have little control, which threatens peoples lives and possessions. The immediate effects of the eruption caused directly by it. The after effects that occur as an indirect effect of the eruption on a longer timescale. Money, food, training and technology given by richer countries to poorer ones, either to help with an emergency or for long term development. Mudflows resulting from ash mixing with melting ice or water- a secondary effect of a volcanic eruption. A map which shows areas tat are at risk from hazards such as earthquakes, volcanoes, landslides, floods and tsunamis. A mega colossal volcano that erupts at least 1000km3 of material. The depression of the supervolcano, marking the collapsed magma chamber. Water that is heated beneath the ground, which comes to the surface in a variety of ways. A geothermal feature in which water erupts into the air under pressure. A section of the earth’s crust where plumes of magma ruse, weakening the crust. These are away from plate boundaries. The point in the earth’s crust where the earthquake begins. A scale ranging from 0-10 used for measuring earthquakes, based on scientific recordings of the amount of movement. The point at the earths surface directly above the focus. Shock waves Mercalli scale The three Ps Prediction Protection Preparation Tsunami Seismic waves generated by an earthquake that pass through the earth’s crust. A means of measuring earthquakes by describing and comparing the damage done, on a scale of I to XII. The collective term for prediction, protection and preparation. Attempts to forecast an event- where and when it will happen- based on current knowledge. Constructing buildings so that they are safe to live in and will not collapse. Organising activities and drills so that people know what to do if an earthquake happens. A special type of wave where an event, often an earthquake moves the entire depth of the water above it. Restless Earth Case Studies The Andes (Young fold mountain range) Context and link to syllabus A case study of one range of fold mountains. Content The ways in which they are used – farming, hydroelectric power, mining, tourism and how people adapt to limited communications, steep relief, and poor soils. See key word list for words in bold below: Farming: Many subsistence farmers grow a variety of crops on the steep slopes. They adapt by using terraces. These flat areas retain water and stop the soil moving downslope. Most crops are grown in the lower valleys, some cash crops (crops grown to sell) such as soya beans, rice and cotton are grown. Hydroelectric power (HEP): The steep slopes and narrow valleys are ideal for HEP as they can be dammed and the rapid flow of water ensures the generation of electricity. Melting snow provides a surplus of water, but this varies throughout the year. In 2009 the El Platanal HEP power plant began generating electricity. Mining: The Andes has a range of important minerals (tin, silver and gold). More than half of Perus exports are from mining in the Andes. The Yanacocha gold mine is the largest in the world, however it causes water pollution as the rock must be sprayed with cyanide. The nearby towns have grown in size due to the mining but this also brings problems such as lack of services and crime. Tourism: There are many natural attractions in the Andes such as mountain peaks, volcanoes, glaciers and lakes. Attractions such as Machu Picchu and the Inca Trail attract many tourists. Other adaptations: Llamas are used as pack animals to reach inaccessible areas. They can carry over 25% of their bodyweight; they are also used for meat, milk and wool. Mt St Helens A case study of a volcanic eruption – its cause; primary and secondary effects; positive and negative impacts; immediate and long-term responses. Use either Mt St Helen’s OR Eyjafjallajökull, Iceland. You only need to know 1 case study. Mt St Helens Erupted at 8.32am on the 18th May 1980. Causes: Destructive plate margin. Oceanic crust subducting beneath continental crust. Mt St Helens is a composite cone volcano. Primary effects: Landslide, pyroclastic flow, trees uprooted, 57 people died. Secondary effects: Roads blocked, water contaminated with ash, machinery/air conditioning systems damaged by ash. Spirit lake filled in. Positive impacts: Ash increased fertility of the soil. Negative impacts: Tourist industry destroyed. immediate responses: Mobilising helicopters to search and rescue. Emergency treatment at nearby towns. Long term responses: Buildings and bridges needed rebuilding. Drainage assessed, forest replanted, removal of fallen timber. Eyjafjallajökull, A case study of a volcanic Iceland eruption – its cause; primary and secondary effects; positive and negative impacts; immediate and long-term responses. Eyjafjallajökull erupted from March to May 2010. Causes: Iceland lies on the Mid Atlantic Ridge, a constructive plate margin (The Eurasian plate moving away from the North American plate). As the plate moves apart magma rises to the surface to form several active volcanoes. Eyjafjallajökull is located beneath an ice cap in southern Iceland, 125km south of the capital city Reykjavik. Eruptions in March were mostly lava eruptions; they were spectacular and fiery but presented little threat. On April 14th a new phase began which was much more explosive. Violent eruptions belched huge quantities of ash into the atmosphere. Primary effects: Day turned to night due to the ash blocking out the sun., rescuers wore face masks to prevent them choking on the clouds of ash. Homes and roads damaged and services disrupted, crops damaged by ash, roads washed away. 100,000 flights cancelled over 8 days. Total loses of £80million. Secondary effects: Sporting events were cancelled or affected due to cancelled flights. Fresh food imports stopped and industries were affected by a lack of imported raw materials. Local water supplies were contaminated with fluoride. Flooding was caused as the lacier melted and torrents of water flowed out from beneath the ice. International Impacts: The eruption of Eyjafjallajökull became an international event in mid April 2010 as the cloud of ash spread eastwards towards Europe. Large sections of European airspace closed down. The knock on effects were felt globally. Business people and tourists were stranded, industrial production was affected as raw materials could not be flown in. Positive impacts: Eyjafjallajökull has become a new Icelandic tourist attraction with its own visitors centre. The eruption gave the country a tourism boost (we travelled there in July 2013 and we are returning in February 2015). For those who went on the trip we did stop at a view point of Eyjafjallajökull but it was unfortunately too cloudy to see the top of the volcano. Lava and ash are rich in nutrients making the soils in volcanic areas very fertile and good for agricultural use. The rocks can be used for building. Geothermal energy is a very valuable resource in Iceland and is used for hot water and to heat swimming pools. Immediate responses: Evacuation. Long term responses: Further research into the effects on ash on aircraft. Reconstruction of roads, local flood defences needed reconstructing. Yellowstone. The characteristics of a supervolcano and the likely effects of an eruption. Exam questions related to supervolcanoes: (Foundation and higher) Describe the size and shape of a supervolcano (2m) (Foundation and higher) Describe the likely worldwide effects of a supervolcano eruption. (6m) Read the case study below and then answer the exam questions. Answers can be found at the bottom of this article. Click on links to get additional information from around the internet. What is a supervolcano? Supervolcanoes are on a much larger scale than ordinary composite cone volcanoes (such as Mt St Helens and Eyjafjallajökull). They can be 1000-2500 times bigger than the Mt St Helens eruption!. Supervolcanoes do not look like composite cone volcanoes. They have depressions in the ground called calderas which are often identifiable by a rim of higher land around the edges. The Yellowstone Supervolcano. The very forces that created such a unique area such as Yellowstone could also be responsible for its destruction and threaten the existence of people. There is evidence that the huge magma chamber is even more colossal than first expected and that it is shifting. Eruptions have happened in the past, 2 million years ago, 1.3 million years ago and 630,000 years ago. Locally the land would be completely destroyed and everything living thing killed. Nationally there will be a loss of 100,000km2 of land and around 90,0000 people may die. The ash would affect transport, electricity, water and farming. Lahars (mud flows) are likely. Internationally the ash would reach the UK in about 5 days. Globally climates would change dramatically, crops would fail and many people would die of starvation. Kobe Japan 1995 (MEDC) A case study of an earthquake in a rich part of the world and one from a poorer area – their CASE STUDY 1: KOBE, JAPAN 1995: GREAT HANSHIN EARTHQUAKE (MEDC). specific causes; primary and secondary effects; immediate and long-term responses – the need to predict, protect and prepare. Contrasts in effects and responses will be clear. CAUSES: At 5.46am on January 17th 1995 the Phillipines plate was pushing beneath the Eurasian plate along the destructive fault line that runs beneath Kobe. The plates had become stuck and pressure began to build up beneath the crust and was finally released leading to an earthquake measuring 7.2 on the richter scale, with tremors lasting 20 seconds. PRIMARY EFFECTS: 6434 people dead and 40,000 injured. Gas mains ruptured, water pipes fractured, sections of elevated road collapsed and railway lines buckled. SECONDARY EFFECTS: 300,000 homeless.2 million people left without electricity and 1 million people had to cope without water for 10days. Fires engulfed the city, devouring the wooden structures, damage to roads restricted access and the fires burned out of control. The economy suffered as there was $220 billion in damage. Companies like Panasonic had to close temporarily. RESPONSES: Friends and neighbours searched through the rubble for survivors, joined by the emergency services when access was possible. Hospitals struggled to cope with the large amount of injured people. Major retailers provided supplies for people and Motorola maintained mobile phone connections free of charge. The recovery longer term was quick. Railways were 80% operational within just a month, most roads were back to normal by July that year. A year later the port was 80% operational again. Buildings which survived the quake had been built to stricter regulations from 1981 onward. Buildings which were older than this were not and collapsed easily. New buildings were built further apart to prevent the domino effect should they fall. High rise buildings are now built with flexible steel frames and rubber blocks put under bridges to absorb shock. The Japanses practice earthquake drills every year to prepare them for another similar event. Over 800,000 people took part in a drill in August 2006. THINKING POINT: HOW DID BEING AN MEDC HELP KOBE RECOVER FROM SUCH A BIG EARTHQUAKE? Haiti 2010 (LEDC) CASE STUDY 2: THE HAITI EARTHQUAKE 2010 (LEDC). CAUSES: The earthquake happened along a conservative plate margin marking the bounder between the North American plate and the Caribbean plate. At 16:53 on January 12th 2010 the island of Haiti was struck by a powerful 7.0 magnitude earthquake. The earthquake was caused by stress building up along the conservative plate margin, when this stress was released there was a sudden slip along the fault. The earthquake was followed by several large aftershocks of up to 5.0 on the Richter scale. EFFECTS:The earthquake devastated large parts of the capital Port-au-Prince and resulted in massive loss of life making it one of the most destructive earthquakes of all time. PRIMARY EFFECTS: 230,000 people were killed. 180,000 homes destroyed by the ground shaking. SECONDARY EFFECTS: 2 million people were affected and 1.5 million were homeless. The homeless were accommodated in over 1100 squalid camps with limited services such as water and sanitation. People lived in these camps for over a year. Cholera claimed the lives of several hundred people mainly children. Storms and flooding caused further hardship in the camps. 19 million chic metres of rubble and debris created- a huge job to clear up. 5000 schools damaged or destroyed. Service such as electricity, water , sanitation and communications were badly disrupted or destroyed. Total damage bill was $11.5billion. RESPONSES: Search and rescue was the immediate response. Assistance was required and so specially trained medics with sniffer dogs and high tech heat sensitive equipment were flown in from MEDCs. Local people made up the majority of the rescuers. Aid arrived from abroad in the form of food, water, medical supplies and temporary shelters (from the USA and Dominican Republic at first.) The United Nations and the USA provided security to maintain law and order and ensure a fair distribution of aid. The UK’s Disasters Emergency Committee (DEC) raised over £100million. This money was used for emergency shelter, medical consultations, clean drinking water and sanitation Temporary shelters became home for more than a year for the homeless, while medical care was very limited. LONGER TERM RESPONSES: 3/4 of damaged buildings were inspected and repaired. 200,000 people have received cash or food for public work such as clearly rubble. Several thousand people have decided to move away from Port au Prince to stay with family, some have emigrated to other countries. The world bank pledged $100million to support reconstruction and recovery programmes in Haiti. How to revise: Japan 2011 Tsunami. A case study of a tsunami – its cause, effects and responses. Make a table to compare the effects and responses of the 2 earthquakes. What do you notice? Case Study: The Tohoku Tsunami, Japan 2011 On the 11th March 2011 a powerful earthquake measuring 9.0 on the Richter scale occurred around 100km east of Sendai on Honshu, Japan, In just 30 minutes a wall of water up to 40m high hit the coast of north western Japan. It was followed in places by up to 9 additional waves up to 10m in height. 3000km of coastline was affected by the waves, which tore through coastal defences. Causes of a tsunami (BBC bitesize) The earthquake that triggered the tsunami occurred at a destructive plate boundary where the Pacific plate was being subducted (pushed under)the North American plate. A segment of rock around 200km long slipped suddenly and flicked upwards by around 5-10m. This sudden uplift displaced (pushed up) the water creating the tsunami. Effects • 200000 people killed • 500km2 coastal plains hit, destroying farmland, settlements and communications. • Ruptured gas pipes led to fires. • Explosions at the Fukushima nuclear power plant- this led to nuclear contamination and the possibility of meltdown as the cooling systems failed. • Electricity lost in 6 million homes, 1 million had no running water, • Further problems were caused by heavy snow and blocked roads. Responses • • • • 100,000 Japanese soldiers sent out to search and rescue. Specialist search and rescue teams flown in from overseas. Exclusion zone set up around Fukushoma, people evacuated from area. Longer term: Re-building, re construction. Port facilities rebuilt, tsunami defence system reconsidered and extended.