Geosphere7th 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 PHYSICAL LAYERS

EARTH’S COMPOSITIONAL LAYERS ←←→→

THE CRUST:

•Solid, outermost layer

•Thick and made of lightweight materials

THE MANTLE:•Middle layer•Made of dense, iron-rich minerals

THE CORE:•Hot, dense nickel and iron at the center of Earth

LITHOSPHERE:•Cool, rigid, outermost layer•Contains the crust and upper mantle •Divided into tectonic plates

ASTHENOSPHERE:

•Solid, plastic layer of the mantle

•Made of rock that flows very slowly

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 What seismic waves are are Seismic waves are waves of Seismic waves are waves of

energy that break through layers energy that break through layers of earths interior and tells you of earths interior and tells you what they are made of.what they are made of.

Danielle VassDanielle Vass

How do seismic waves How do seismic waves give information to give information to scientists.scientists. The scientist The scientist

uses a tool called uses a tool called a seismograph.a seismograph.– The seismograph The seismograph

has different has different frequencies for frequencies for each layer it goes each layer it goes through.through.

– http://science.howstuffworks.chttp://science.howstuffworks.com/earthquake4.htmom/earthquake4.htm

Danielle Vass Danielle Vass

• 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.

GeosphereEffects of a large-scale volcanic eruption on

the global climate

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 volcanic eruptions most

often occur!

David

Hudson

EarthquakesEarthquakes

• 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://imagecache5.art.com/p/LRG/27/2707/RR1ND00Z/melissa-farlow-a-rock-formation-shaped-by-wind-erosion-overlooks-the-grand-canyon.jpg

http://media.photobucket.com/image/plant%20on%20a%20sidewalk/freakshow745/Best%20Pics/100_0029.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