Download 6th - inside earth study guide1

Name: ____________________________________
Test Date: ____________________________________
6th Grade Earth Science – Earth Layers, Magnetism & Plate Tectonics
Understand the following vocabulary terms:



















crust – the layer of rock that forms Earth’s outer surface
lithosphere – a rigid layer made up of the uppermost part of the mantle and crust
mantle – the layer of hot, solid material between Earth’s crust & core
asthenosphere (convecting mantle) – the soft layer of the mantle on which the lithosphere
floats
outer core – a layer of molten iron and nickel that surrounds the inner core of the Earth
inner core – a dense sphere of solid iron and nickel at the center of the Earth
magnet – a material that attracts steel, iron, cobalt, and nickel
Earth as a magnet – the Earth acts like a magnet because of the liquid outer core made of iron
and nickel which spins as the earth rotates and creates a magnetic field and the north & south
poles on earth
compass – an instrument composed of a small, light-weight magnet called a needle, that is
balanced on a frictionless bearing
continental drift – the hypothesis that the continents slowly move across the Earth’s surface
sea-floor spreading – the process by which molten material adds new crust to the ocean floor
subduction – the process by which ocean floor sinks beneath a deep-ocean trench and back
into the mantle.
plate tectonics – the theory that pieces of Earth’s lithosphere are in constant motion, driven
by convection currents in the mantle
divergent boundary – a plate boundary where two plates move away from each other
convergent boundary – a plate boundary where two plates move toward each other
transform boundary – a plate boundary where two plates move past each other in opposite
directions
earthquake – when plate boundaries slide past each other , build up pressure & cause a
sudden, violent shift
volcano – forms where plates diverge and magma reaches earths surface & where plates
collide and one subducts into the mantle forming molten material
mountain building – when two plates collide & crush together causing land to be pushed up,
resulting in the folding and breaking of Earth’s crust
Be prepared for questions similar to those below: See bold for suggested answers.
1. In the table below, study what you know about each layer including its location, composition (iron,
nickel, rock, crust & upper mantle) and state of matter (solid or liquid). Also, be able to identify
where each layer is located (from an image).
Crust
Location on Earth: Top layer also part of the lithosphere
Composition (made of): Rock
State of Matter: Solid
Lithosphere
Location on Earth: part crust, what the tectonic plates are made of
Composition (made of): crust & upper mantle, rock (hard like jolly
rancher)
State of Matter: Solid
Upper Mantle
Location on Earth: part of the lithosphere
Composition (made of): Rock
State of Matter: Solid
Middle Mantle/
Asthenosphere
Location on Earth: Under the lithosphere, the lithosphere floats on this
(where the convection currents are)
Composition (made of): Rock (soft like laffy taffy)
State of Matter: Solid
Lower Mantle
Location on Earth: Below the asthenosphere
Composition (made of): Rock
State of Matter: Solid
Outer Core
Location on Earth: Under the mantle
Composition (made of): Metal (iron & nickel)
State of Matter: Liquid
Inner Core
Location on Earth: Under the mantle
Composition (made of): Metal (iron & nickel)
State of Matter: Solid
2. List all the ways in which the Earth is like magnet.
i. both have poles (north & south)
ii. both are composed of (nickel & iron)
iii. both create a magnetic field
iv. both attract iron & nickel
3. What creates Earth’s magnetic field?
The rotational forces within the Earth’s liquid iron layer (the outer core)
4. Why is a compass composed of a frictionless bearing & a lightweight magnet?
To allow the needle to turn easier because Earth’s magnetic field is very large
5. Where can a compass be used for navigation & why?
On land & at sea because the magnetic field of earth is so large it can be used by a
compass anywhere
6. The tectonic plates are part of this Earth layer
Lithosphere
7. On average, the Earth’s lithospheric plates move about how far each year?
A few centimeters
Complete the plate boundary table below:
Plate Boundary
Definition
Is crust created
or destroyed?
destroyed
What geologic
event occurs?
Volcanoes and
Earthquakes
Mountain
Building
Convergent
Where two plates
come together,
collide, when one
goes beneath the
other it is
subduction
Divergent
Where two plates
move away from
one another,
divide, separate
created
Volcanoes,
Earthquakes
Mountain
building
Transform
Where two plates
move past each
other, slide
neither
Earthquake
8. At what type of plate boundary do mountains form?
Convergent, (underwater – divergent)
9. At what type of plate boundary do volcanoes occur?
Convergent & Divergent
10. What is the cause of an earthquake?
When plates slide past one another at a transform boundary and energy stored in
the Earth’s crust is suddenly released.
11. What is it called when an oceanic plate dives beneath a continental plate?
Subduction
Use the map below to answer the questions that follow.
12. Describe what happens at the two plate boundary locations between the Pacific Plate & the North
American Plates?
 Where the arrows move in opposite directions past one another, this is a transform
boundary and earthquakes may occur here.
 Where the arrows move towards one another, the plates are converging (i.e.
colliding) & one must subduct (the pacific) beneath the other (the North American).
A mountain range occurs here.
13. Describe what happens between the American Plate and the Eurasian plates?
 Where the arrows move away from one another, the plates are diverging
(separating) & new crust is created here (and possibly volcanoes).
14. Compare what happens between the Cocos & Caribbean Plates to what is happens between the
Antarctic & South American Plates.
 Both plate relationships are convergent. One plate in each will subduct beneath the
other causing volcanic activity or mountain formation.