Download Tectonic Cycle

REFERENCE: The Blue Planet
An Introduction to Earth System
Science. Brian J. Skinner and
Barbara W. Murck (2011) Third
Edition. John Wiley and Sons Inc.
It is the solid Earth composed primarily of:
: Any naturally formed, nonliving, firm
coherent aggregate mass of solid matter that
constitutes part of a planet.
: The irregular blanket of loose,
uncemented rock particles that covers the solid
Earth.
Understanding plate tectonics and the
rock cycle is the key to understanding the
geosphere's role in the Earth system.
Layers of Different
Composition
The oceanic crust is
composed mainly of
basalt, rich in iron and
magnesium.
The continental crust
is composed mainly of
granite, rich in
aluminum.
Although they are
both rich in oxygen
and silicon, the rocks
that compose the
oceanic crust are of
higher density than
the rocks that
compose the
continental crust.
Tectonics is the study of the movements and deformation
of the lithosphere. Such motions involve complicated
events, both seen and unseen. The study of the processes
by which the lithospheric plates move and interact with
one another is called plate tectonics.
• In 1508 Leonardo da Vinci discovered fossil seashells high in
the mountains of Italy.
• In the 1800s James Hutton incorporated the idea of uplift and
erosion into the concept of the rock cycle.
• In the 1830s Charles Darwin made important observations in
South America that were key pieces to the rock cycle.
A final piece of the rock cycle
puzzle was answered:
What is the “force” which has
lift up the mountains?
Answer: Plate Tectonics
World’s landmasses were
formed together in a single
huge continent called:
PANGAEA.
Pangaea was somehow
disrupted and its fragments
(the continents of today)
slowly drifted to their
present position.
It is hypothesized that convection also
occurs in the interior of the Earth due
to the geothermal gradient.
This geothermal gradient
and convection are
responsible for rising hot
rocks and side-ways flow,
which are the factors that
control the positions of
ocean basins and continents.
Therefore, these processes
determine the shape of the
Earth's surface.
The source of the Earth’s
magnetism lies in the
molten outer core.
As a result of the Earth’s
rotation, the molten iron
of the outer core flows
continually around the
solid inner core.
The flowing stream of
molten iron causes an
electrical current in turn
creates the magnetic field.
Paleomagnetism is the magnetism in rocks that records the
directions of ancient magnetic fields at the time of rock formation.
Lava extruding
along a midocean
ridge forms new
oceanic crust.
As the lava cools,
it becomes
magnetized with
the polarity of
the Earth's
magnetic field.
A & B - Divergent
C & E - Convergent
Subduction
D - Convergent
Collision
F - Transform Fault
Watch the YouTube video called
“Plate Tectonics”
Convergent Margins
Himalaya
Los Andes
Divergent Margins
ten Brink U S et al. Geological Society of America Bulletin
2009;121:1522-1536
©2009 by Geological Society of America
Geodesy, also called geodetics, a branch of earth
sciences, is the scientific discipline that deals with
the measurement and representation of the
Earth, including its gravitational field, in a threedimensional time-varying space.
GPS is funded by and controlled by the U. S.
Department of Defense (DOD). While there are
many thousands of civil users of GPS worldwide, the system was designed for and is
operated by the U. S. military.
GPS is the only system today able to show us
the exact position on the Earth anytime and
anywhere.
The first GPS satellite was called GPS Block I and
it was launched in 1978. The launch of the 24th
satellite in 1994 completed the system.
All 24 GPS satellites orbit at 11,000 nautical
miles above the Earth.
Four GPS satellite signals are used to compute
positions in three dimensions and the time
offset in the receiver clock.
New GPS Technology
goes from meters to cm
… or even mm
20 mm/yr
Mann,et. al., 2002
Involves the firing of a laser
(Light Amplification by
Stimulated Emission of
Radiation) pulse through a
telescope at passing satellites
and measuring the time taken
for the pulses to return to earth.
Watch the YouTube video called
“The Early Earth and Plate Tectonics”