Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Earthquakes An earthquake is one of the worst natural disasters on our earth. We think that the cause = the reason for something crust = the top part of the earth decade = ten years disaster = when something very dangerous happens and a lot of people die ground we stand on is very stable, but it isn’t. It moves quite a lot. In the last few decades scientists have been able to find out why earthquakes happen. Earthquakes happen when there is a sudden vibration in the earth’s crust. It’s like a large lorry that travels down your street. When it passes by, you feel your house shake. Earthquakes can be caused by a lot of things : + Volcanoes that suddenly erupt erupt = to break out or explode + Meteorites that hit the earth + Undergrounds explosions fault = where two plates meet + Buildings that fall apart lorry = a car that carries lots of goods But most earthquakes happen because the earth’s plates move. magma = rock in the inner part of the earth that is liquid In the middle of the 20th century scientists found out that continents do not always plate = the earth’s crust broke up into many plates and the continents move on these plates earth’s surface is made up of many such plates. Where two plates meet magma reach = get to HOW PLATES MOVE release =let go stay in the same place. They have been moving on plates for millions of years. The comes out of the inner part of the earth . These areas are called faults—breaks in the earth’s crust. When two plates move away from each other lava or slide =move, go down magma comes out of the earth. Most of this happens at the stable = it doesn’t move bottom of oceans, where the earth’s crust is very thin. Lava sudden =unexpected, quick cools down when it reaches the water and underwater mountains are formed. surface =the top layer towards each other =here: two objects move to each other When plates push towards each other—one of them slides under the other. Rocks are pushed up and new mountains are formed. Some plates slide past each other— for example, one moves north and the other moves south . When these plates move along faults a lot of energy is released and the biggest earthquakes happen. 1 Earthquakes We only hear about earthquakes once in a while , but they really happen every edge =border ,outer part of day. There are more than 3 million earthquakes every year—about 8,000 every day occur = happen or one every 11 seconds. once in a while = sometimes But most of them are very weak or they happen in places where nobody lives. Some take place = happen of them take place on the sea floor. volcano = a mountain that often explodes and rock, gas and lava come out of it WHERE DO EARTHQUAKES HAPPEN ? weak = not very strong zone = places, areas Earthquakes occur all over the world but there are places where they happen more often. Big earthquakes can be found where plates meet. 80% of the world’s earthquakes happen around the Pacific Ocean—near the east coast of Asia and the west coast of America. Japan has over 2,000 earthquakes every year and California and South America are also very active earthquake zones. The edge of the Pacific Ocean is also called the “Ring of Fire” because there are also many active volcanoes in this region. The Ring of Fire around the Pacific Ocean 2 Earthquakes compare = to exchange the information you have with others damage =destruction direction =way magnitude = tells us how strong an earthquake is man-made = something caused or made by a person medium-sized = not so big and not so small EARTHQUAKE WAVES When there is a sudden movement in the earth’s crust, energy moves in the form of waves . It’s like dropping something into water. Body waves move through the inner part of the earth and surface waves travel over the earth’s surface. Body waves can travel very fast—up to 8 km a second. They travel through rock , water and gas . When they reach other places on the earth’s surface they can be registered there. They are usually the first waves to get to the surface. Surface waves cause the most damage, but they move very slowly. These waves come at the end of an earthquake. MAN-MADE QUAKES movement =when something moves Sometimes people can make earthquakes happen. They can fill man-made lakes rate =rank, measure how strong something is these tests can help scientists find out how quakes happen. reach =go from .... to registered = recorded spread out = to move with water after building a dam—or they test atomic bombs underground. Some of HOW EARTHQUAKES ARE MEASURED With a machine called a seismograph scientists can tell where an earthquake happened and how strong it was. The place in the earth where the movement takes place is called the focus or Epicentre hypocentre. From here, waves start to spread out in all directions. This focus can be very near to the surface or it can be hundreds of km below it. The area on the surface exactly above the focus is Focus called the epicentre. This is the place where the waves hit first and where the most damage is done. Whenever an earthquake hits us you hear how powerful it is. The Richter Scale is used to rate the magnitude of earthquakes. Small quakes have a rating of under 4. You won’t see a lot of damage here. Medium-sized earthquakes reach between 5 and 7 on the scale, and the really big ones are above 7. The largest earthquake that has ever been registered was at 9.5 on the Richter scale. There are more than 100 seismograph stations all over the world. When the earth shakes seismologists compare the information they get and then they can tell where the earthquake really happened. 3 Earthquakes EFFECTS OF EARTHQUAKES collapse = to fall down concrete = a very hard material made of cement developing countries = the poorest countries in the world Earthquakes make the ground move. Buildings shake and many of them collapse. Landslides also happen when rocks get loose. Another danger is fire. In 1906 San Francisco was hit by a big earthquake and many houses burned down because they were made of wood. especially =above all injured = hurt landslide = rocks move down mountains and destroy houses or block roads lead to =to be the reason for loose =movable, to come free, not fixed occur = happen safe water = clean water The San Francisco earthquake of 1906 destroyed supplies =reserves treat =care for, take care of most parts of the city When an earthquake occurs on the sea floor, big waves - called tsunamis—hit the coast. They often come without any warning and they kill many people and destroy buildings and streets near the coast. Earthquakes also can lead to diseases, especially in developing countries. When water supplies are destroyed people don’t have safe water to drink. Sometimes earthquakes also hit hospitals where injured people are treated. DEALING WITH EARTHQUAKES We understand earthquakes a lot better today than we did 50 years ago, but we still can’t do very much about them. They are so powerful, that we cannot control them. Scientists can tell us in which regions earthquakes will probably happen, but they can’t tell us exactly where. So what can we do about earthquakes ? We can make our houses we live in and buildings we work in safer. Today architects use materials that won’t collapse when an earthquake hits—like steel and concrete. 4 Earthquakes destroy =damage , ruin height =how high something THE BIGGEST EARTHQUAKES IN HISTORY 856 200,000 people are killed in one of the deadliest earthquakes in history in is Damghan, Iran. magnitude = how strong or powerful an earthquake is . It is measured on the Richter 1138 An earthquake in Aleppo, Syria kills 230,000 scale record =write down, keep 1556 The deadliest earthquake in history hits Shensi province in China. Almost 1 information million people are killed. serious = dangerous 1755 The most serious earthquake in Europe hits Lisbon, Portugal. The whole city is destroyed. About 70,000 people get killed. 1906 The city of San Francisco is hit by a large earthquake. A big fire destroys most of the city. About 500 people die. 1908 Messina, Sicily is totally destroyed by a large earthquake . About 70,000 people are killed. 1923 Tokyo, Japan is destroyed by an earthquake with a magnitude of 8.3 . 150,000 people are killed. 1960 The strongest earthquake ever recorded hits Chile. It reaches 9.5 on the Richter scale. 20,000 people die. 1964 The strongest earthquake in North America hits Anchorage Alaska. Ocean waves reach a height of 20 metres. 200 people are killed. 1976 The biggest earthquake ever recorded in China leaves 242,000 people dead. 5 Earthquakes What can earthquakes be caused by . Give some examples 1. ______________________________________________________________________________________________ 2. ______________________________________________________________________________________________ 3. ______________________________________________________________________________________________ 4. ______________________________________________________________________________________________ What do continents move on ? __________________________________________________________________________ What happens when plates come together ? _______________________________________________________________ ____________________________________________________________________________________________________ ____________________________________________________________________________________________________ Why don’t we hear about most of the earthquakes ? ________________________________________________________ ____________________________________________________________________________________________________ ____________________________________________________________________________________________________ What is the “Ring of Fire “ ? ____________________________________________________________________________ ____________________________________________________________________________________________________ ____________________________________________________________________________________________________ There are two types of waves . Describe them ! Body waves Surface waves How do people cause earthquakes ? _____________________________________________________________________ ____________________________________________________________________________________________________ ____________________________________________________________________________________________________ 6 Earthquakes Complete the following text with the words from the box ! damage surface recorded crust seismograph hypocentre seismologists scale epicentre magnitude directions With a machine called a __________________ , scientists can tell us where an earthquake occurred and its ____________________ . Every earthquake starts at the focus or _______________ . This can be near the earth’s __________________ or many hundred kilometres in the earth’s ______________ . From here waves travel in all ________________ . The area directly above the focus is called the earthquake’s _________________ . This is the area where most ________________ is done. The Richter ______________ tells us how powerful an earthquake is. The biggest earthquakes ever __________________ on earth were at 9.5 on this scale. When an earthquake happens _________________ all over the world compare their information . Explain in English : magma _____________________________________________________________________________________________ ____________________________________________________________________________________________________ disaster _____________________________________________________________________________________________ ____________________________________________________________________________________________________ tsunamis ____________________________________________________________________________________________ ____________________________________________________________________________________________________ collapse _____________________________________________________________________________________________ ____________________________________________________________________________________________________ volcano _____________________________________________________________________________________________ ____________________________________________________________________________________________________ magnitude ___________________________________________________________________________________________ ____________________________________________________________________________________________________ 7 Earthquakes TRUE OR FALSE ? T F Big earthquakes can be found where plates meet. The Ring of Fire is around the Atlantic Ocean. Most of the world’s biggest quakes occur here. In 1906 many houses in San Francisco burned down because they were made of wood Earthquakes that happen on the ocean floor are called tsunamis. The earth’s crust is thinnest under the continents. Faults are places where two plates meet. they can be hundreds of kilometres long. Earthquakes can also be caused by underground explosions. Most earthquakes happen after big volcanoes erupt. When there is a sudden movement in the earth’s crust, energy moves in the form of waves. Body waves are fast and travel through all kinds of material A machine made to find out how strong earthquakes are is called a hypocentre. the Richter scale tells you how many people died in an earthquake. The place above the earth where the most damage is done is called the epicentre. Today , it is important to use wood when you build houses or buildings. 8 Earthquakes Write a newspaper report about the picture below ! ____________________________________________________________________________________________________ ____________________________________________________________________________________________________ ____________________________________________________________________________________________________ ____________________________________________________________________________________________________ ____________________________________________________________________________________________________ ____________________________________________________________________________________________________ ____________________________________________________________________________________________________ ____________________________________________________________________________________________________ ____________________________________________________________________________________________________ ____________________________________________________________________________________________________ ____________________________________________________________________________________________________ ____________________________________________________________________________________________________ ____________________________________________________________________________________________________ ____________________________________________________________________________________________________ ____________________________________________________________________________________________________ 9 Earthquakes 1 2 3 4 5 6 7 8 9 10 Across 1. Down city in North America that was destroyed 1. machine that tells scientists how strong by a big earthquake an earthquake is 5. centre of an earthquake 6. rock in the inner part of the earth that is buildings that are protect people from liquid earthquakes place on the surface of the earth where 3. name of the scientist who made a scale the earthquake waves hit first to measure earthquakes 7. 9. Oberfläche 2. 4. material that is used to build houses and big ocean wave that is caused by earthquakes 10. what the continents move on 5. where two plates meet 8. the top part of the earth 10 Earthquakes 1 S A N F R A E 3 I R S I 6 M C M A O H G T 7 8 R E P I C A R R 9 P S U H S 10 P L A T 2 N C I S C O O 4 N T 5 F O C U S G M A R U U E N L T A E N T R E M I R F A C E E 11 Earthquakes Find 12 words in the grid that have to do with earthquakes ! P D Z D M A G M A P T D O A I O I O C O L L A P S E M I K B R S E I S M O G R A P H T M P F A U L T D V N M Y I L D B G S S H R Z P F I P R C D O Q A D T H W F L T T V Q E R I O E Y E Q A R A F U J U N A U T C M R A V K T C D P Z T Z H S U Q F N E A E O E J G R H G K T A Y Z S V S R R E D E C M J L 12 Earthquakes Find 12 words in the grid that have to do with earthquakes ! P D Z D M A G M A P T D O A I O I O C O L L A P S E M I K B R S E I S M O G R A P H T M P F A U L T D V N M Y I L D B G S S H R Z P F I P R C D O Q A D T H W F L T T V Q E R I O E Y E Q A R A F U J U N A U T C M R A V K T C D P Z T Z H S U Q F N E A E O E J G R H G K T A Y Z S V S R R E D E C M J L 13