Earthquake!! Year Four http://www.youtube.com/watch?v=4Y-62Ti5_6s
Today’s Lesson What you will learn: The structure of the Earth What this has to do with earthquakes How and why earthquakes form How earthquakes move How an earthquake damages land and structures How earthquakes are measured http://www.ucmp.berkeley.edu/geology/tectonics.html
Tectonic Plates Tectonic plates form part of one of the earth’s layers. They are like pieces of a jigsaw They are constantly being pushed around, bumping and grinding into each other - when this happens, an earthquake usually occurs Tectonic plates move continents at approx 50-100mm each year notes!
Now lets watch it again…… http://www.ucmp.berkeley.edu/geology/tectonics.html
Australian Earthquakes? Where do you think the most earthquakes would occur? Do we get earthquakes in Australia? http://www.ga.gov.au/bin/drawquake_foyer.pl http://www.ga.gov.au/bin/listQuakes
The Layers of the Earth Does anyone know any of the names of the layers of the Earth? http://earthquakesyearfour.blogspot.com/
The Inner Core Hottest part of the Earth Possibly as hot as the Sun Solid sphere 2500km across – the distance from Sydney to Cairns! notes! http://earthquakesyearfour.blogspot.com/ Outer Core
The Outer Core Liquid layer which is 2200km thick Temperature approximately 5000 degrees Made up of hot, molten lava notes! http://earthquakesyearfour.blogspot.com/ Mantle
The Lower and Upper Mantle Lithosphere Lower – made from solid rock Upper - also known as the lithosphere 200km thick Broken into the tectonic plates – oceanic and continental notes! http://earthquakesyearfour.blogspot.com/ Crust
The Crust 25km of loose rock Makes up less than 1% of the Earth We live on the top of the crust This is the part of the Earth that gets broken and split in an earthquake notes!
Blanket Activity Two helpers needed Each to push the ends of the blanket towards each other What happens? What is this representing?
A bridge across a tectonic plate that has divided How did this happen?
How? So how does an earthquake happen? Using all of this new knowledge – you tell me! notes!
Faults Fault- an area or line along a tectonic plate that the released energy from an earthquake travels along. The earth’s crust is pushed up or down, or over or under when this happens, creating different size faults – like scars on rock or even mountains! notes! http://earthquake.usgs.gov/learning/animations/animation.php?flash_title=Normal+Fault&flash_file=normalfault&flash_width=220&flash_height=320
Focus and Epicenter The underground starting point of the earthquake is called the focus The above ground starting point of an earthquake is called the epicentre notes!
Seismic Waves Waves of force that start from the focus and travel outwards There are primary (p-waves) and secondary waves (s-waves) p-waves occur first, then s-waves Seismic waves are what causes the shaking and splitting of the earth Watch this animation to see how they can travel ALL over the world! notes! http://www.pbs.org/wnet/savageearth/animations/earthquakes/index.html
Richter Scale Earthquake strength is classified on the Richter Scale
2004 Earthquake On Boxing Day, 2004, a 9.3 earthquake occurred along Sumartra’s west coast This was one of the deadliest natural disasters of all time – but not because of the earthquake The focus was on an oceanic tectonic plate, which caused a deadly tsunami that hit Indonesia, Sri Lanka, India and Thailand the hardest http://en.wikipedia.org/wiki/File:2004_Indonesia_Tsunami_Complete.gif
Questions? Check the question chart – have we answered everything? http://earthquake.usgs.gov/learning/kids//