Capter+4+Section1

__Chapter 4 section 1__

__By:Ryan Callenbach__ __Earth__ __The Earth consist of 4 parts.These parts ar____e mantle,inner core, and outer core.The crust is the top layer .The mantle is the biggest part It__ __is under the crust.Then goes the outer core surrounding the inner core at the middle of the earth.__

__ The crust!! __ __ Your jorney begins in the crust.The crust is the layer at the top that forms around the earth.The crust is a layer of soild rock that includes both dry land and the ocean floor.On the crust you will find mountains water and soil on the earths surface.The crust is m ____ uch thinner than the mantle that lies beneath it.The crust is thickest under high mountains and thinnest beneath the ocean.The crust beneath the ocean is called the oceanic crust.The Oceanic crust is mostly rocks.The types of rocks are basalt and granite. __ __ The Mantle __ __ Your journey downwards continues.About 40 kilometers beneath the surface,you cross a boundary.Below it you find a solid substance called the mantle.The mantle is a layer of hot rock under the crust that is very hot but still solid.Different layers of the hot mantle have many physical characteristics.The mantles thickness is 2,867km.Its temp is 870c -4,400c. __

__ The lithosphere __ The uppermost part of the mantle and the crust together form a rigid layer called the lithosphere.The lithosphere averages about 100 kilometers thick.

__The Asthenosp____here__ __Below the cold brittle lithosphere,you encounter material that is hotter and under increasing pressure.As a result,the part of the mantle just beneath the lithosphere is less rigid than the hot rock above.This part of the mantle is kind of soft ant can bend like plastic.This soft layer is called the asthenosphere.Although it is softer if you were is kick part of it you would stub and hurt your toe.__

__The Core__ __After travling through the mantle you reach Earths dense metallic core.It consists of two parts a liquid outer core and a solid inner core.Together,the inner and outer core are 3,486 kilometers thick.__

__Outer core and Inner core__

The outer core is a layer of molten metal that goes around the inner core.The Inner Core is a Dense ball of metal.In the inner core extreme pressure squeezes the atoms of iron and nickel so much that they can not spread out and become liquid.Most of the current evidence suggest that both parts of the core are made if iron and nickel.

__ Seismic waves __ Geologists have used two main types of evidence to learn about earths interior direct evidence from the rock samples and indirect evidence from seismic