Download TAKS Review

TAKS Review
Objective 5
The student will demonstrate an understanding
of earth and space systems.
Plate Tectonics History
• Wegener’s theory of Continental Drift—
continents move slowly from Pangaea to
present day
• Sea Floor Spreading—magma wells up
forcing the sea floor apart and forming
the mid-ocean ridge
• Theory of Plate Tectonics—Earth’s crust
is broken into parts called plates that
move or float on top of the mantle
Continental Drift
• Same “fresh water” reptile fossils
along South American & African
coastlines
• Similar rock formations on both the
South American & African coastlines
• Similar glacier evidence on both
continents
Sea Floor Spreading
Sea Floor Spreading Evidence…
 Rocks close to the midocean ridge are very young
and the age of these
rocks continues to
increase the farther you
get from the ridge
 Iron bearing minerals
show a record of Earth’s
magnetic field reversing;
these rocks show the
same field direction an
equal distance on either
side of the mid ocean
ridge
Continental Plates
Divergent Plate
Convergent
Transform
Boundary
Boundary
Boundary
Trench-formed where
Sea Floor Spreading
one plate subducts
under another
Subduction Zone
Plate Tectonics
Rift Valley
A rift valley is a long,
deep valley bounded by
normal faults. It forms
where the earth’s crust
is being pulled apart. A
rift valley can appear on
land or beneath bodies
of water, where two
continental plates are
separating, or on the
ocean floor along the
crest of a mid-ocean
ridge, where new ocean
crust is forming.
Rotation
Earth rotates
or spins on its
axis, taking
~24 hrs to
make one
rotation. This
is what gives
us day and
night.
Revolution
The revolution of the Earth around the sun
takes 365.25 days. This is what brings us the
seasons.
The Moon
• Rotates on its axis
once every 29 days
• Revolves around
the Earth once
every 29 days
• Therefore, we
always see the
same side of the
moon
Moon Phases
New Moon = no
reflected light
• We see the moon because it
reflects light from the sun
Full Moon = full • phases caused by moon’s
circle of reflected revolution around the Earth
light
• phases are named for the lit
portion of the moon
•Waxing = getting lighter; Waning
= getting darker
• Crescent & Gibbous refer to the
shape of the light being reflected
Condensation
Precipitation
Evaporation
Evaporation
Runoff &
Groundwater
The SUN is the
Precipitation can be
driving energy force
in the form
of
rain,
Condensation
= thecycle
formation of clouds
of the water
sleet, snow, Water
or hail
Water on the ground
can either RUNOFF
into streams, rivers,
lakes, etc. or
percolate through
the soil to become
GROUNDWATER
Cycle
Evaporation = liquid
water to gaseous
water or water
vapor
Renewable vs. Nonrenewable
• Renewable resources are replaced
naturally in a relatively short period of
time (such as plants)
• Nonrenewable resources cannot be
replaced as they are used (such as iron &
fossil fuels)
• Inexhaustible resources are renewable
resources with an almost limitless supply
(such as wind and sunlight)
Endangerment of Species
• Can result from human activities
having negative effects on the
environment
• Modification of the water, nitrogen,
and/or carbon cycles
• Not only can these lead to species
endangerment, but also extinction
For Example…
• Deforestation: the destroying and cutting
down of forests
– Loss of habitat for millions of species
results in their extinction
– Fewer trees to take in CO2 and trees
are burned producing even more CO2
– Annually, there is an approximate net
loss (difference between trees cut down
and those planted) of 23.2 million
acres…that’s like cutting down a little
more than an acre of trees for every
single person in Texas. (about the size
of a football field)
For Example…
• Modifying the Carbon Cycle by increasing the
amount of CO2 in the air from the burning of trees
and fossil fuels for electricity and vehicles of
transportation
– CO2 is a greenhouse gas; by increasing the levels of CO2,
it acts as a blanket on the Earth raising the average
global temperature
– On a global scale C02 makes the biggest contribution to
global warming (about 64%). The C02 concentration in the
atmosphere is now about 30% higher than 200 years ago.
If it continues to increase at the same rate it could
nearly double by the year 2035. Burning of oil, coal and
natural gas and the clearing and burning of vegetation are
the main causes of the increased levels of this gas.
For Example…
• Modifying the Nitrogen Cycle can result in the
formation of nitric acid and ground-level ozone
– Human health concerns include effects on
breathing and the respiratory system, damage to
lung tissue, and premature death. Small particles
penetrate deeply into sensitive parts of the lungs
and can cause or worsen respiratory disease such
as emphysema and bronchitis, and aggravate
existing heart disease
– Nitrogen pollution can result in acid rain causing
the destruction and possibly extinction of native
plant species which in turn can lead to the
extinction of those animal species that depend on
the native plants
For Example…
• Demands for water both for consumption
and irrigation continue to rise faster than
the population rate
– Use of rivers causes the flow to be reduced
downstream and lakes to dry up resulting in a loss of
habitat for native species
– Pumping out of water from groundwater sources
such as aquifers leads to land subsidence destroying
habitat
– Rising levels of pollution in water result in less
consumable water by living organism causing loss of
habitat and possible extinction of species
– Draining of water-covered lands such as swamp
lands also result in habitat destruction and loss of
species
Reminders…
• Plate tectonics is the movement of crustal
plates which can lead to sea floor spreading,
formation of rift valleys, mountain building,
and other landform changes
• The moon goes through a cycle of changes
both visually (phases) and forces acting on
the Earth (tides)
• Species endangerment/extinction can be the
result of human activities as well as natural
events modifying nature’s cycles
• Energy from the sun drives our weather as
is an almost inexhaustible resource
»Any questions???