Name:____________________
Test: Core, Mantle, Crust;
Spheres of the Earth
Studying the Earth
Note:
 You must know all vocabulary words and be able to give an example of
each
 You must be able to accurately label a diagram of the layers of the
Earth (including the discontinuities)
 You must be able to answer question about any of the experiments
conducted in class.
Direct observation is when you can use
Direct Observation
your 5 senses, sight, hearing, touch,
taste and smell directly to study
Definition
something.
What do we study with it?
We can only study what is on or near
the first few kilometers of the crust
using direct observation.
Indirect observation is when you
Indirect Observation
cannot use your 5 senses directly to
study something so you must use
Definition
models or technology to study it.
What do we study with it?
We study the mantle and the core by
indirect observation – using a
seismograph and rock samples and
models.
We use a seismograph and study
the seismic waves. There are two
What type of machine do we use to
types of seismic waves: S-waves
study the core or the mantle?
stop in liquid and P-waves slow
down.
The Hydrosphere (all water on Earth),
What are the three spheres of the the Lithosphere (the hard rock surface
Earth?
of the Earth) the Atmosphere (all the
gases that surround Earth.
Our lithosphere is mostly made up of
What is our lithosphere mostly made rock, sand, and soil.
of?
What are the three main layers of
the Earth?
On/in which layer does all life exist?
The core, the mantle and the crust.
All life exists on or near the top of
the crust.
What are the two types of crust?
There is oceanic and continental
crust.
Which type of crust is thinner but
denser?
The oceanic crust is thinner but denser
(heavier) that is why it is on the
bottom!
Which type of crust is thicker but
lighter?
What two main elements is our crust
made of?
What type of rock is oceanic crust
mostly made of?
What type of rock is continental
crust mostly made of?
What are the segments of the
Earth’s crust that are moving called?
The continental crust is thicker but
less dense (lighter) that is why it is on
the top!
Our crust is mostly made of the
elements silicon and oxygen.
Oceanic crust is made up of a heavy
dense igneous rock called basalt (to
help you remember – salty oceans –
basalt!).
Continental crust is made up of the
lighter igneous rock – granite.
The segments of pieces that the Earth
is broken into are called plates. These
plates are floating on a semi-solid
asthenosphere (in the mantle).
What thin layer separates the crust
from the upper mantle?
The Mohorovicic discontinuity is the
thin layer between the crust and the
upper mantle.
What thin layer separates the lower
mantle from the outer core?
The Gutenberg discontinuity is the thin
layer between the lower mantle and the
outer core.
What is the property that gives part
of the mantle (the asthenosphere)
the ability to flow?
The property of plasticity allows our
asthenosphere to flow – which causes
our plates to move. This is the bottom
part of the upper mantle!
What is liquid rock that hardens
outside the Earth called?
Liquid rock that hardens outside of
earth is called Lava.
What is liquid rock that hardens
inside the Earth called?
Liquid rock that hardens inside of
earth is called Magma.
How does the Earth spin on its axis?
How do scientists know the “states”
of the layers of Earth that we
cannot use direct observation for?
The Earth wobbles as it spins on its
axis!
Scientists study the seismic waves that
return from the core and the mantle.
They noticed that p-waves slow down
when they reach the areas that we
believe are semi-solid or liquid
(asthenosphere and the outer core).
They notice that they stop when they
hit the lithosphere, the lower mantle
and the inner core, which we believe
are solid.