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Geosphere. 7 th Period. Earth’s Composition and Structure. The composition and structure of Earth are very different among the numerous layers. The differentiation of the earth is due to the occurrences in the formation of the solar system 5.5 billion years ago. EARTH’S COMPOSITIONAL
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Geosphere 7th Period
Earth’s Composition and Structure The composition and structure of Earth are very different among the numerous layers. The differentiation of the earth is due to the occurrences in the formation of the solar system 5.5 billion years ago.
EARTH’S COMPOSITIONAL LAYERS EARTH’S PHYSICAL LAYERS → ← • LITHOSPHERE: • Cool, rigid, outermost layer • Contains the crust and upper • mantle • Divided into tectonic plates • THE CRUST: • Solid, outermost layer • Thick and made of lightweight materials • ASTHENOSPHERE: • Solid, plastic layer of the mantle • Made of rock that flows very slowly • THE MANTLE: • Middle layer • Made of dense, iron-rich minerals • THE CORE: • Hot, dense nickel and iron at the • center of Earth • MESOSPHERE: • “the middle sphere” • OUTER CORE: • Outer shell of Earth’s core • Made of liquid nickel and iron • INNER CORE: • Sphere of solid nickel and iron • at the center of the Earth
By: Hunter Tolley -Asthenosphere: the major importance of this layer is to hold the earth’s tectonic plates. -This layer is the upper part of the mantle. It is very hot but not liquid at a temperature of 1600 degrees Celsius -And this layer is roughly 250km thick
By: Hunter Tolley -Earths tectonic plates are huge and have jagged edges. -They move very slowly at an inch per year if that -Most geologic activity occurs at plate boundaries -Convection current deep in the mantle causes the plates to move
Main Cause of Earthquakes • The major cause of earthquakes is the stress that builds up between two tectonic plates. They collide together and therefore cause an earthquake • Another major cause of earthquakes is from volcanic eruptions Shannon Bratton
The Effects on Land • Can cause buildings to collapse • Ground shaking • Landslides • Floods Shannon Bratton
The effects on life in surrounding areas • Loss of life • Building collapse • Loss of basic necessities – water, electricity, shelter • Fires • Disease • Road/bridge damage Shannon Bratton
What seismic waves are • Seismic waves are waves of energy that break through layers of earths interior and tells you what they are made of. • Danielle Vass
How do seismic waves give information to scientists. • The scientist uses a tool called a seismograph. • The seismograph has different frequencies for each layer it goes through. • http://science.howstuffworks.com/earthquake4.htm Danielle Vass
GeosphereEffects of a large-scale volcanic eruption on the global climate • Can change Earth’s climate for several years. • Less sunlight can get to Earth’s surface because of ash and gases that are spread across the atmosphere. • This can drop the surface temperature. Emily Hunter
Mount Pinatubo • Mt. Pinatubo erupted in 1991 • The amount of sunlight that got to Earth’s surface went down by 2-4%. • Because of this, the average global temperature decreased by many tenths of a degree Celsius over a span of many years after 1991. Emily Hunter
Where earthquakes and volcaniceruptions most often occur! David Hudson
Earthquakes • The largest and most active earthquakes lie along the tectonic plate boundaries. David Hudson
Volcanoes • Volcano eruptions occur most frequently along the Pacific Ring of Fire, which accounts for about 80% of the earth’s total volcanic eruptions. David Hudson
Geosphere: Erosion Ethan Rogers • Erosion is the removal and transport of surface material. • Erosion is what makes rocks in bodies of water smoother • Erosion can be used in relative dating, such as the round-topped Appalachian Mountains, which are older than the jagged Rocky Mountains http://www.superiorstonemfg.com/yahoo_site_admin/assets/images/New_River_Rock.24191148.jpg
Geosphere: Erosion Ethan Rogers • Constant erosion cause rocks to gradually shrink which causes them to sink below the Earth’s crust; this means the Earth’s surface is constantly changing • Water, wind and plants are the most common form of natural erosion http://media.photobucket.com/image/plant%20on%20a%20sidewalk/freakshow745/Best%20Pics/100_0029.jpg http://imagecache5.art.com/p/LRG/27/2707/RR1ND00Z/melissa-farlow-a-rock-formation-shaped-by-wind-erosion-overlooks-the-grand-canyon.jpg
Geosphere: Erosion Ethan Rogers • Wind Erosion • Loose soil, sand, and other lightweight materials can be blown away by the wind. • This can form amazing “sculptures” http://a.abcnews.com/images/Technology/nm_Vermilion_080326_ssh.jpg
Geosphere: Erosion Ethan Rogers • Water Erosion • Waves can wash away a coastline • Rivers can create gorges and canyons http://jimmyng.files.wordpress.com/2009/06/grand_canyon6.jpg