Download Earth`s Interior

Earth’s Interior
https://www.youtube.com/watch?v
=mOSpRzW2i_4
Seismic waves are measured by
seismometers
The study of
seismic waves
(seismology)
enables us to
infer the
composition of
the earth.
The Four Layers
The Earth is composed of
four different layers. The
crust is the layer that you
live on, and it is the most
widely studied and
understood. The mantle is
much hotter and has the
ability to flow. The outer
core and inner core
are even hotter with
pressures so great you
would be squeezed into a
ball smaller than a marble if
you were able to go to the
center of the Earth!
Earth’s Interior
• Within the Earth
density,
pressure, and
temperature all
increase with
depth
ESRT Page 10
Heat is created by the radioactive
decay and primordial energy
(left over from Big Bang)
The Crust
The crust is composed of two rocks. The
continental crust is mostly granite. The oceanic
crust is basalt. Basalt is much denser than the
granite. Because of this the less dense continents
ride on the denser oceanic plates.
The Lithosphere
The crust and the rigid outer shell of the
mantle together make up a zone of rigid,
brittle rock called the Lithosphere.
• Moho
discontinuity –
the boundary
between Earth’s
crust and mantle
– Seismic waves
speed up here
due to there being
different material
Asthenosphere
• Part liquid, part solid layer of the mantle,
referred to as the plastic mantle
The Mantle
The Mantle is the
largest layer of the
Earth. The middle
mantle is composed of
very hot dense rock that
flows like asphalt under
a heavy weight. The
movement of the middle
mantle
(asthenosphere) is the
reason that the crustal
plates of the Earth
move.
The Outer Core
Molten, Iron-rich,
layer
Is this a solid or
liquid?
Liquid layer
Earth’s magnetic field is generated
by convection in outer core
The Inner Core
Solid, iron rich
A zone on the
opposite side of the
earth from where an
earthquake has
occurred where no
seismic waves are
recorded.
Due to the way that
seismic waves travel
through the different
materials within the
Earth.
P and S waves get
refracted (bent)
when they hit
different materials
within the earth
Shadow Zones
• http://www.iris.edu/hq/programs/education
_and_outreach/animations/18