Transcript A Model of Earth`s Interior

A MODEL OF EARTH’S INTERIOR
Scientists infer most if the properties of
the Earth’s interior through the study of
seismic (earthquake) waves.
Through many studies and experiments,
scientists have found that seismic waves
refract, reflect, change velocity, and
become absorbed by various parts of the
Earth’s interior.
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ZONES OF EARTH
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The studies of seismic waves indicate that the Earth is
composed of many layers.
The crust is the outermost part of the Earth below the
atmosphere or hydrosphere. This layer is mostly solid rock,
but includes soil and eroded/weathered rock.
~ The crust is divided into two major divisions:
continental
crust and oceanic crust.
~ The continental crust is usually much thicker and less
dense than the oceanic crust .
~ Continental crust is made up of granitic rocks, oceanic
crust is made up of basaltic rocks.
Below the crust, is the mantle. This layer is mostly solid
rock and the thickest layer. This layer is also separated from
the crust by a thin boundary called the Moho.
Together the crust and the upper portion of the mantle is
called the lithosphere. The lithosphere is divided up into
sections called plates.
ZONES OF EARTH CONT.
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Below the lithosphere, is the other portion of the
upper mantle called the asthenosphere. In this
section, seismic waves decreased in velocity. The
asthenosphere is said to be plastic like, that is at least
partly molten. Much of the magma and lava is
thought to originate here.
Beneath the mantle,
the Earth’s core is
divided into two parts –
the inner core and
the outer core.
EARTH’S CRUST
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The earth’s crust is divided into two major
divisions: continental crust and oceanic crust
The continental crust makes up the continents and
larger islands. This crust is made largely of
granitic rocks and it is less dense than oceanic
crust.
The oceanic crust makes up the crust beneath the
oceans. This crust is made largely of basaltic rocks
and it is more dense than continental crust.
The Earth’s crust is composed of low-density rocks
with a mixture of granitic and basaltic
compositions.
Granite
Basalt
ALL OF THE OCEANIC AND CONTINENTAL
PLATES