ACADEMIC YEAR SOCIAL STUDIES YR 9 CONCEPT REVIEW NOTES UNIT 2 : EARTHQUAKES & VOLCANOES What are volcanoes and earthquakes like?

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1 ACADEMIC YEAR SOCIAL STUDIES YR 9 CONCEPT REVIEW NOTES UNIT 2 : EARTHQUAKES & VOLCANOES What are volcanoes and earthquakes like? Pages ) What are you going to learn about in this unit? the distribution of volcanoes and earthquakes how the dangers may be reduced the causes and effects of the volcanoes and earthquakes 2) In what is this unit going to help you? Understand what can be done to reduce the worst effects Develop an interest in volcanoes and earthquakes Be aware of the problems that a disaster causes Where do volcanoes and earthquakes happen? Pages Volcanoes: A cone shaped mountain or hill often made up of lava and ash Active volcano: Volcano that has been erupted recently and is expected to erupt again Dormant volcano : A volcano that has been erupted in the last 2000 years but not recently Extinct volcano: A volcano that is not expected to erupt again Ring of fire: A circle of active volcanoes found around the edge of the Pacific Ocean Earthquake: A sudden movement or tremor of the earth s crust Seismograph: An instrument used to measure the strength of an earthquake Tsunami: An earthquake in the sea or ocean

2 Zones of activity: Areas, usually along plate boundaries where earthquakes and volcanoes are common 1) Mention the three types of volcanoes? Active volcano Dormant volcano Extinct volcano 2) What does the scientist still find it difficult? to predict exactly when and where an eruption will happen 3) where is the greatest volcanic activity? On Iceland 4) Give on example of a powerful earthquake? San Francisco 5) What can earthquake causes? Buildings to collapse and landslides to occur 6) Explain about the distribution of earthquakes around the world? Long narrow belts, one belt goes down the middle of the Atlantic Ocean another follows the west coast of North and South America and then goes all the way round the edge of the Pacific Ocean to new Zealand 7) Why does earthquakes and volcanoes often occur in the same place? Because they all lie in long narrow belts as well as whenever an earthquake will happen it will cause the volcano to erupt 8) Suggest reason for the name of ring of fire? Because it is a circle of active volcanoes that is found around the edge of the Pacific Ocean ( it is in a circle and the volcanoes are active) There are thousands of volcanoes around the world Wherever the volcanoes erupt there will be danger, and probably damage Most volcanoes occur in narrow belts or are grouped together in small clumps The Indian ocean earthquake of 2004 caused tsunami waves that killed more than 300,000 people Volcanic eruptions are confined to certain areas in the world

3 Earthquakes are happening all the time Scientists have concluded that volcanoes and earthquakes are usually found in long narrow zones of activity Note: study diagrams A and B from pages or from the portal homework week 2 ( Any 5 places) How do volcanoes and earthquakes happen? Pages crust: The thin outer layer of the earth plates: large section of the earth s crust plate boundary: The place where plates meet on the earth s surface and where most of the world s earthquakes occur and volcanoes may be found Mantle: The layer of the earth beneath the crust and above the core Core: The central part of the earth Magma: Molten rock below the earth s surface 1) How volcanoes and earthquakes happen? Plates move towards and is forced underneath South America plate then the plate will rub together and it will cause earthquake. Friction and heat from mantle melts the rocks then the hot liquid rock (magma) will rise and then the volcanic eruption will happen. 2) How does the movement of plates cause earthquakes? Plates scrapping together makes the ground shake and sets of earthquakes 3) Why does Britain have no active volcanoes or major earthquakes? Because Britain is far away from plate boundaries 4) Which two plates meet along the west coast of USA? Nazca plate South American plate

4 5) Why earthquakes happen in san Francisco? Because it s near the plates boundaries 6) On which plate does Britain lie? Eurasian plate 7) Explain how can a volcano happen? The plates move together the friction between them makes the rock melt. The liquid rock magma rises upwards and erupts on the surface volcano The earth was formed 4,600 million years ago Since it has been slowly cooling down a thin crust has formed round the outside Crust in not all one piece but is broken into several piece The plates float on this layer and move about very, very slowly just a few millimeters in a year What are volcanoes? Pages vent: An opening in the earth s crust through which material is forced upwards during a volcanic eruption Lava: Molten rock (magma) that usually flows from the crater of an active volcano Volcanic bombs: large rock fragments thrown out by an erupting volcano Magma chamber: where molten rock is found deep below the earth s surface Crater: A roughly circular opening at the summit of a volcano

5 1) Give example of an active volcano? Mount Etna 2) Why Mount Etna is an active volcano? Because it has erupted as recently as 1971,1983, 1994, 2000,2002 and 2005 and is expected to erupt again in the near future 3) Why dormant volcanoes may be dangerous? Because it is difficult to predict when they are going to erupt again 4) Why extinct volcanoes are called extinct? Because they are dead and their volcanic activity is finished 5) Give examples of extinct volcanoes? The Edinburgh volcano in Scotland and Snowdon in Wales 6) What will happen when volcano erupts? When a volcano erupts, the magma from below the earth s surface rises up the vent to the volcano s crater. It then explodes into the air as ash, dust and volcanic bombs, and flows out as molten lava. 7) What was the greatest volcanic explosion of modern? The greatest volcanic explosion of modern times happened when the Indonesian island of Krakatoa erupted in The noise from that was so loud that it could be heard over 4,700 km (3,000 miles) away in Australia 8) Give example of peaceful volcanoes? Mauna Loa

6 The magma may appear as flows of molten lava, as volcanic bombs, as fragments of rock or simply as ash and dust There are over 700 active volcanoes around the world Britain s last volcanoes erupted over 50 million years ago and have mostly been worn away by erosion Note: STUDY DIAGRAMS A AND B FROM PAGES STUDY DIAGRAMS A,B,C,D FROM PAGES What happens when a volcano erupts? Pages Natural hazard: A good force of nature such as: earthquake, floods or storms, which it is a threat of danger to people and their way of life 1) Give four examples of natural hazard? Earthquakes, floods, storms or strong winds 2) Why do volcanic areas often have a lot of people living in them? Because ash and lava turn into rich fertile soil which is good for farming. Good farming areas are attractive places 3) Why Mount Etna is called an active volcano? Because it has been erupting for the last 100 years (1971,1983,1992,2000,2002 and 2005) and is expected to erupt again for the near future 4) What were the problems caused by Mount Etna erupting? Ski slopes and cable car stations are damaged Research observatory near the summit was completely wiped out Millions of Tonnes of lava gushed out the crater and engulfed a hotel,three restaurants and 25 houses and numerous orange groves and vine yards

7 5) What happens when Mount Etna erupts? Volcano gently rumbles and steams Loud explosion as volcano erupts Ash, dust and lava blasted out of the volcano Lava pours down the mountain side Buildings and property are destroyed Rescue services goes into action When volcano erupts it can cause serious problems. People are in danger and their surroundings can be several damaged The largest and most active volcano in Europe is the 3,340 high Mount Etna, it is located in Italian island of Sicily How can be earthquake danger be reduced? Pages Predict: to estimate when or where an earthquake will occur 1) What are the three Ps policy? Predict, protect and prepare 2) Why the state has adopted the three Ps policy? To reduce the worst effects of this natural hazard Predict: Earthquakes are most likely after long periods without any plate movement There will be many small foreshocks before the main quake. It can be measured with seismograph Animals will act strangely, snakes and rats crawl out of their holes and dogs howl

8 Protect: All new buildings must comply with strict earthquake planning regulations Building regulations must be adhered to and frequent safety checks carried out Existing buildings, roads and bridges should be strengthened Prepare: Prepare disaster plans and carry out regular practices Train emergency services such as: police, fire and ambulance crew Organise emergency supplies of food, water and power in advance Most towns and cities in California have been built in active earthquakes zone along the san Andreas fault Two earthquakes compared. Pages Give reason: 1) Despite the best preparations and well- practiced, earthquakes still kill people? Because it is impossible to predict when and where exactly an earthquake will happen and how powerful it is going to be 2) The San Francisco quake of 1989 was very powerful but yet there few deaths? Because they have followed the three Ps policy which are predict protect and prepare California is one of the world s most wealthy regions and has the resources and huge sums of money that a successful disaster plan requires The Indian government was seriously short of money, and had to ask for 1 billion of international aid to support the rescue effort

9 San Francisco, USA 1989: Highly trained rescue teams reached the disaster areas within minutes Helicopters were used to transport rescuers and evacuate the injured Hospitals were put on red alert and saved many lives Several huge fired were quickly brought under control by well- trained fire crews Gujarat, India 2001: Badly designed and poorly built houses collapsed, crushing people inside Emergency electricity supplies and telephone links failed to work Local rescue workers were poorly prepared and arrived too late to save many lives over a million homeless people had no shelter, warm clothing or food Note: study diagram d page 35 study diagram e page 39