Download The Earth is Moving Big Book

The Earth is Moving & Changing
By: Karen Hernandez
The Earth is moving and
changing!
I just thought you might like
to know.
Page 1
What is inside the Earth?
What are the forces behind all the
change?
The basis for science is discovery
based on what is actually observable.
But since humans have only sampled
Earth’s deep interior up to 12
kilometers, geologists have to use
indirect methods to hypothesize what
Earth’s interior layers may be like.
Most of the evidence comes from
observing geologic structures and
activity on the surface of the Earth.
Other evidence used to understand
Earth’s interior structure comes from
the study of seismic waves.
Through the scientific process,
theories have been proposed about
Earth’s interior and the causes of
change on the exterior.
Page 2
Earth’s interior is made up of layers
with different compositions. The
temperature and pressure in these
layers increases with the depth.
The inner core of our planet is
believed to be a solid iron ball about
as hot as the surface of the sun. It is
pressed into a dense solid state by
tremendous pressure.
High temperatures with slightly less
pressure seem to cause the metallic
elements of the outer core’s metal to
be molten.
Scientists call the thick middle
layer of the Earth the mantle. Even
within the mantle, there are distinct
layers ranging from partly melted
convecting rock to a more brittle rock
nearer the surface.
The thin, rocky, outer layer of the
Earth is called the crust. By sampling
the crust, geologists know with more
certainty its composition, density,
physical state, and convection
tendencies.
Page 3
Observation of the Earth’s
continents and how they fit together
started a scientists’ hypothesis of
continental drift in the early 1900’s.
Alfred Wegener supported his
hypothesis that the continents had
once been attached and were now
drifting slowly apart with evidence
through fossils, rock types, and
ancient climatic zones.
Since then, technological advances,
such as the GPS (Global Positioning
System), sonar and deep sea drilling
have helped scientist study the
lithosphere, which is the upper mantle
and the crust. They have used the
evidence to develop new hypothesis
for what is now called plate tectonics.
Page 4
The Earth’s lithospheric plates are
constantly moving and colliding at
their boundaries, creating stresses
that cause interesting geologic
formations and catastrophic natural
phenomenon.
Geologic formations at the
boundaries in the sea are ocean
trenches and mid ocean ridges.
Boundaries on the continents result
in lithosphere being uplifted into
mountain ranges and sinking to form
rift valleys.
Dramatic movements between
plates shake land during earthquakes,
send molten lava out of volcanoes, and
send humungous tsunamis onto the
land. The results are destructive and
deadly to the people living where
these natural disasters occur.
Page 5
Within the state of California, lies a
boundary between the North
American Plate and the Pacific Plate.
This transform boundary has shaped
California’s topography through its
strike-slip fault called the San
Andreas Fault.
The Transverse Ranges and Coastal
Ranges have formed as chunks of the
lithosphere have been uplifted.
Humungous blocks of rock have
dropped down, forming The Los
Angeles Basin and San Francisco Bay.
The subduction and melting of the
oceanic plate has formed the volcanic
mountains of the Cascade Range:
Mount Shasta and Lassen Peak.
Page 6
Thanks to many years of research
by dedicated scientists, we can now
predict when a volcano will blow its
top.
Although we still can't predict when
an earthquake will happen, we have
learned much about earthquakes as
well as the Earth itself from studying
them.
Seismologists can determine the
focus and epicenter of an earthquake
through comparing seismic waves
recorded by seismographs.
The Richter Scale and Moment
Magnitude Scale have been developed
to describe an earthquake’s
magnitude. The Mercalli Scale is used
to describe its destructibility.
Page 7
Architects have learned how to
build flexible structures that can
withstand the strong shaking
produced by earthquakes.
In poor underdeveloped countries,
builders are limited to the materials
they can afford and often can’t take
advantage of this knowledge of
earthquake safe construction. The
destruction which occurs in those
places is exponentially greater.
People who live in earthquake or
tsunami zones are being educated as
to the signs of these disasters and
how to react to save their lives.
Page 8
Earthquakes and tsunamis have
destroyed whole regions and claimed
countless lives, leaving devastation
and despair. The economy of the
affected region is often crushed and
unable to support its citizens.
Homeless people are left with the pain
of having lost family members, yet
they need to keep on living and rebuild
their lives from nothing.
However, out of the midst of this
hopelessness, rise incredible tales of
survival and acts of heroism and
generosity. The rallying together of
the world to help the victims has
renewed faith and hope to many.
Page 9
Someday you can go yourself to help
or become a scientist to help discover
ways to predict and warn people of
destructive phenomenon.
You can make a difference where
you are right now by donating to
organizations which send food, water,
medical supplies and workers to help
in the tremendous task of rebuilding
lives.