EARTHQUAKES

What is an Earthquake? FAULT PLANE EPI CENTRE HYPER CENTRE An earthquake is what happens when two blocks of the earth suddenly slip past one another. The surface where they slip is called the fault plane. The location below the earth’s surface where the earthquake starts is called the hypocenter, and the location directly above it on the surface of the earth is called the epicenter. The ground shakes during an earthquake because the plates underneath are continuously moving at a slow pace, but as they are moving they are rubbing against each other and eventually on plate will slip under another and this sudden 'shift' causes an earthquake. The primary waves are the ones that come first then the next movement are the secondary waves. FAULT PLANE EPI CENTRE HYPER CENTRE

What causes an Earthquake? Earthquakes are caused by the movement of the earth's tectonic plates. Earthquakes occur where the earth's plates meet along plate boundaries. Earthquakes occur at three types of plate boundaries: convergent, divergent, and transform. Convergent: An earthquake occurs at a convergent fault line when tectonic plates collide. Divergent: During an earthquake at a divergent fault line, tectonic plates separate. Transform: In an earthquake at a transform fault line, energy stored in tectonic plates is released. This release of energy causes the two plates to rub against each other. 20113034@my.nd.edu.au pw Chelsea#! Tectonic boundaries tra http://econtent.thelearningfederation.edu.au/ec/viewMetadata.action?id=L5833&q=tectonic+transform&topic=%22Science%22&start=0&sort=relevance&contentsource=&v=text&field=title&field=keyword.text&field=description&field=id&field=topics.all.text&contenttype=%22Interactive%20resource%22&userlevel=all&kc=any&lom=true&scot=true&follow=true&topiccounts=true&rows=20&fromSearch=true

Affects on the Environment/People Injuries or death Loss of homes Landslides Fires Tsunami??? http://www.neok12.com/php/watch.php?v=zX06611b03056651036a0141&t=Natural-Disasters

What instruments are used to measure an Earthquake? Seismograph: A seismograph is an instrument used for recording the intensity and duration of an earthquake. A short wiggly line that doesn’t wiggle very much means a small earthquake, and a long wiggly line that wiggles a lot means a large earthquake Richter scale: Richter Scale is a scale that is used to gauge the intensity of an earthquake. A Richter Scale ranges from one to ten. The lower the scale reads, the lower the intensity of the earthquake is.

Tsunami A tsunami is a large ocean wave usually caused by an underwater earthquake. With typical waves, water flows in circles, but with a tsunami, water flows straight. This is why tsunamis cause so much damage.

ACTIVITY In Groups of 3-4, you will need to research an Earthquake/Tsunami of your choice and report your findings back to the class. You will need to include the following information: - Name of the Earthquake/Place where it happened? - The magnitude of the earthquake - A brief summary of how it occurred, and - The effect it had on the environment/ people

Extension Activity- building a seismograph What you will need: Cereal box Cardboard sheet (size of cereal box) Plastic cup with cover Pencil Scissors Strip of paper (2" wide, by 2' long) Piece of string Rubber bands Instructions: Cut a rectangle out of both sides of a cereal box, leaving 1 inch wide edges. Cut in the middle of the bottom edge, two narrow horizontal slots about 2 inches wide through which you can slide the 2 foot long strip of paper. Pierce a hole at the center of the top cup cover and another at the bottom of the cup. Push a pencil, point down, through the two holes. Fill the cup with sand around the pencil. Thread string through the holes near the top of opposite sides of the cup.  Hang the cup from the center of the cereal box by tying the string around a small stick at the center at the box top. Adjust the length of the string so the tip of the pencil touches the strip of paper threaded through the bottom cuts of the box. Glue the bottom of the cereal box to one of the sheets of cardboard. Shake the cardboard base back and forth.  The weighted pencil should stay put and will make a mark on the paper strip you have moved through the cardboard base.  You will need a friend to guide the strip of paper through the slits.

Conclusion What are 3 things you learnt about earthquakes?