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1.1 Notes
Earth has several layers
What causes a material to
sink or float?
Think About…
Vegetable oil/water/alcohol
demo
Think About…
http://www.youtube.com/watch?v=oCkacB_72i0
Watch…
Which has more mass?
Density
Density depends on both the
size of the object and the matter contained inside
Density
Density is the amount of mass per unit
volume of a substance. The bricks are more dense than the
feathers. The water bottle is more dense than
the balloon.
Density
Density
Density depends on the
material an object is made from, NOT its size.
Density
An object will float if the density of
the object is LESS than the density of the liquid it is in.
Sinking and Floating
An object will sink if the
density of the object is MORE than the density of the liquid it is in.
Sinking and Floating
What is more dense?Coke vs. Diet CokeWater vs. Salt Water
Think About…
4.6 billion years ago, Earth
formed as material collided and stuck together.
The planet grew larger as more and more material stuck together.
Earth is made up of materials with different
densities
Over time, denser
materials such as iron and nickel sank toward the center of the Earth, and less dense materials rose to the surface.
Earth is made up of materials with different
densities
Slowly, Earth’s main layers
formed-the core, the mantle, and the crust.
Earth is made up of materials with different
densities.
How can we know what Earth’s
interior is like? No one has seen it.
Earth’s layers have different properties
Scientists study the energy
from earthquakes or underground explosions they set off.
This energy moves slower through less dense materials or liquids and faster through denser materials or solids.
Earth’s layers have different properties.
The core is Earth’s densest
region and is made up of two parts.
Core, Mantle, Crust
The inner core is a
ball of hot solid metals.
The pressure from the layers above is so great that the inner core is a solid despite the fact that it is extremely HOT!
Core, Mantle, Crust
The outer core is a layer of
liquid metals that surrounds the inner core.
Core, Mantle, Crust
The mantle is Earth’s thickest
layer-about 2900 km (1700 mi)!
Core, Mantle, Crust
The mantle is
hot rock that is less dense than the core.
The very top part of the mantle is cool and rigid.
Core, Mantle, Crust
The crust is a thin layer of cool
rock.
Core, Mantle, Crust
There are two basic types of crust:
Continental crust-includes the continents and major islands
Oceanic crust-includes all the ocean floors
Core, Mantle, Crust
Earth’s crust and the very top
of the mantle together form the lithosphere. Greek prefix litho=“stone” or
“rock”
Lithosphere and Asthenosphere
The lithosphere sits on top of the
asthenosphere-a layer of hotter, softer rock in the upper mantle.
Lithosphere and Asthenosphere
The asthenosphere is
soft enough to flow slowly, like hot tar.
Imagine the lithosphere as solid pieces of pavement resting on hot tar.
Lithosphere and Asthenosphere
The lithosphere does NOT form
a continuous shell around Earth.
The lithosphere is made up of many
plates
The lithosphere is broken into
many large and small slabs of rock called tectonic plates.
The lithosphere is made up of many
plates.
We do not now how or when
these giant plates formed.
The lithosphere is made up of many
plates
Most large tectonic plates
include both continental crust and oceanic crust.
Remember, when you’re looking at a map, you’re only seeing the part of Earth’s crust that rises above the ocean.
The lithosphere is made up of many
plates.
All of this information leads us to
2 questions. Have the continents always been
where they are today? If not, how did they move to their
present positions?
To be continued…
Think About…
1.Which of the following best
describes Earth’s mantle?A.The densest of Earth’s layersB.The home of all life on EarthC.The thickest layer of hot rockD.The thinnest and hottest
layer
Review
2. Tectonic plates make up Earth’sA.lower mantleB.lithosphereC.asthenosphereD.inner core
Review
3. Density is a measure of the amount ofA. matter in a given volumeB. volume that a substance takes upC. space between objectsD. pressure in a given volume
Review
