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A slideshow on volcanoes

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  1. 1. Earthquake Information EARTHQUAKE INFORMATION An earthquake is when the ground is shaken caused by rocks releasing energy. Earthquakes, also known as tremors, are caused when the plates inside the earth move or crash into each other. Earthquakes normally occur over plate boundaries. Earthquakes cause many deaths. It is said that about 10,000 people die yearly from earthquake eruptions. Earthquakes can cause fires, mud slides, floods, and tsunamis. Usually after massive earthquakes little ones happen shortly after. Here is a few facts: -The worlds largest earthquake was a 9.5 earthquake in Chile on May 22, 1960. -The first earthquake that we know of was in California about 50 kilometres away from Los Angeles in 1769. -It is said that there are about 500,000 earthquakes around the world each year. About 100,000 of them we can feel and about 100 of them cause damage. Weird fact: Earthquakes can happen on the moon they are called moonquakes. They are not very big but they still do happen. Information from- and disasters/earthquake-profile/ and BC SCIENCE 7 Textbook and 01_ss_full-thumb-1200x791-62422.jpg
  2. 2. Faults FAULTS A fault is where the Earth has cracked open. This shows that there has been an earthquake. Big faults show that the tectonic plates have been pushing together very hard. There are three different types of faults that I will be talking about: -Normal Faults -Reverse Faults -Strike Slip Faults Interesting fact: -The fault in San Andreas California caused chaos, many people were injured during this time. Information from- and BC SCIENCE 7 Textbook and http://blogs-
  3. 3. Normal Faults NORMAL FAULTS A normal fault is where the rock above the fault moves down and the fault below moves up. Normal faults usually happen where the lithosphere is being stretched. Other times it happens near deltas, at the end of big lumps of sand or mud. information from- and and BC SCIENCE 7 Textbook and nce/ES_11.2A_files/slide0010_image022.jpg
  4. 4. Reverse Faults REVERSE FAULTS Reverse faults are cracks, in the crust, where one of the plates are pushing up into another plate. Or when the plate is folding up because it is being pushed by another plate. In a reverse fault the rock that is above the fault is pushed up and over the rock below the fault. Information from- and BC SCIENCE 7 Textbook and reversefault.jpg
  5. 5. Strike Slip Fault STRIKE SLIP FAULTS A strike slip fault is when the two rocky blocks rub side by side. If the block rubs to the left it is called a left lateral. If the block rubs to the right it is called a right lateral. The result of this fault’s motion is caused by strong cutting forces. The strike slip fault is studied the most out of all the faults. Strike slip faults are also the longest fault out of them all. Information from- and and and BC SCIENCE 7 Textbook and er_features/PublishingImages/strike-c.gif
  6. 6. Seismic Waves SEISMIC WAVES A seismic wave is a wave of energy that travels rapidly through the Earth, and causes an earthquake. Seismic waves are studied by seismologists and geophysicists. The speed of the waves depend on how dense they are. The speed starts to gain the deeper the wave is. it goes about 2 to 8 kilometres in Earth’s crust and about 13 kilometres in the mantle. Information from- and BC SCIENCE 7 Textbook and ter_diagram.gif
  7. 7. Primary Waves PRIMARY WAVES Primary waves are one of the kinds of body waves that happen during an earthquake. A primary wave is one of the main waves that occur after an earthquake. A primary wave is the fastest kind of seismic wave. Primary waves go as fast as 1450 miles per hour in the air and 500 miles per hour in granite. Primary waves move like a slinky. Fact -A primary wave is called that because it is the first wave to appear during an earthquake -Animals can actually hear the primary waves going through the air. Information from- and BC SCIENCE 7 Textbook and
  8. 8. Secondary Waves SECONDARY WAVES A secondary wave is another type of body wave that occur during an earthquake. Secondary waves move like waves in a rope. The secondary wave can only go through liquid not solid things like the primary wave can. Fact -A secondary wave is called that because it is the second wave to appear during an earthquake. Information from- and BC SCIENCE 7 Textbook and
  9. 9. Surface Waves A surface wave is yet again another type of body wave that occurs during an earthquake. A surface wave is the slowest wave that occurs. Surface waves cause the most damage during an earthquake. Surface waves move just like secondary waves. Information from- and BC SCIENCE 7 Textbook and 1.php
  10. 10. Locating an Earthquake LOCATING AN EARTHQUAKE When an earthquake occurs the first question asked is where was the earthquake? Scientists use the time of the seismic waves to show the locations. Well primary waves are faster than secondary waves. So it is possible to determine where the earthquake was by measuring the time when they got there. The further the waves are the further the earthquake stretches. Information from- 118/index.html and BC SCIENCE 7 Textbook and ring_french_nationa_seismic_survey_institute_seismic_wav es_seismograph_m_16574.jpg
  11. 11. Hypocentre HYPOCENTRE Where the earthquake happens in the Earth is where the hypocentre is, also known to be called the focus. The primary and secondary waves come out of the hypocentre. Information from- epicenter.htm and and BC SCIENCE 7 Textbook and urficialGeologyandHazards/Earthquakes/Publishi ngImages/eq-2b.gif
  12. 12. Epicentre EPICENTRE Where the earthquake starts on the surface it is called the epicentre. The epicentre is directly above the hypocentre. The epicentre is directly above the place where the fault begins. The surface waves come from the epicentre. Information from- epicenter.htm and and BC SCIENCE 7 Textbook and http://earthquakesandplates.files.wordpress.c om/2008/05/epicenter.gif
  13. 13. Seismograph SEISMOGRAPH A seismograph is an tool used to measure earthquakes. Seismographs have a heavy pendulum with a needle out above a revolving drum. The drum has a device that makes the needle move and make drawings. This is how it records earthquakes. Information from- and BC SCIENCE 7 Textbook and ph
  14. 14. Bedrock BEDROCK Earthquakes happen along faults, tectonic plate boundary zones or along the mid oceanic ridges. At these spots there are big amounts of rock that slide past each other and can become stuck because of friction. The friction is overpowered when the stress has enough force to cause a slip in the rock. Information from- and BC SCIENCE 7 Textbook and ock
  15. 15. Seismogram SEISMOGRAM When an earthquake occurs a seismograph takes a reading on everything that happened the results of the readings and measurements is called a seismogram. Many years ago a seismogram was a pencil connected to a spinning drum the pencil would draw a lot of lines. All of these lines show you the seismic waves and other activity during the earthquake. Information from- arths_movement.html and BC SCIENCE 7 Textbook and
  16. 16. Measuring Earthquakes MEASURING EARTHQUAKES The size of the earthquake depends on the size that the fault was and the size of the slip on the fault. Scientists can not just measure earthquakes with a measuring tape since the faults are kilometers deep in the Earth’s crust. Scientists use seismogram readings made on a seismograph at the Earth’s surface to show how large it was. When a small line is drawn that shows that is was a small earthquake and when a big line is drawn it shows that there was a big earthquake. Information from- and BC SCIENCE 7 Textbook and 6.f1.gif
  17. 17. Richter Scale RICHTER SCALE Seismologists use a method called the Richter scale. This scale shows the magnitude that the earthquake was. The scale shows all earthquakes magnitude from 0 to 10. Information from- and BC SCIENCE 7 Textbook and /richter-scale.gif
  18. 18. Tsunamis TSUNAMIS Some earthquakes happen under water, this causes the water to get disrupted so the waves start to get bigger. The waves will get very massive after a little while and start coming towards land and cause major damage where the massive wave hits. Information from- cs/earthquake.html and BC SCIENCE 7 Textbook and
  19. 19. Liquefaction LIQUEFACTION When an earthquake occurs the ground shakes and causes wet soil to act like it is now liquid. The liquid like soil will start to sink down underneath buildings and cause them to collapse. This does not always happen underneath buildings it can happen anywhere. Information from- hazard/earthquakes/pages/liquefaction-information.aspx and BC SCIENCE 7 Textbook and ction_at_Niigata.JPG/400px-Liquefaction_at_Niigata.JPG and
  20. 20. Thanks for watching myslideshow.I hope you enjoyed it.